draft-ietf-detnet-security-13.txt   draft-ietf-detnet-security-14.txt 
Internet Engineering Task Force E. Grossman, Ed. Internet Engineering Task Force E. Grossman, Ed.
Internet-Draft DOLBY Internet-Draft DOLBY
Intended status: Informational T. Mizrahi Intended status: Informational T. Mizrahi
Expires: June 14, 2021 HUAWEI Expires: August 5, 2021 HUAWEI
A. Hacker A. Hacker
MISTIQ MISTIQ
December 11, 2020 February 1, 2021
Deterministic Networking (DetNet) Security Considerations Deterministic Networking (DetNet) Security Considerations
draft-ietf-detnet-security-13 draft-ietf-detnet-security-14
Abstract Abstract
A DetNet (deterministic network) provides specific performance A DetNet (deterministic network) provides specific performance
guarantees to its data flows, such as extremely low data loss rates guarantees to its data flows, such as extremely low data loss rates
and bounded latency (including bounded latency variation, i.e. and bounded latency (including bounded latency variation, i.e.
"jitter"). As a result, securing a DetNet requires that in addition "jitter"). As a result, securing a DetNet requires that in addition
to the best practice security measures taken for any mission-critical to the best practice security measures taken for any mission-critical
network, additional security measures may be needed to secure the network, additional security measures may be needed to secure the
intended operation of these novel service properties. intended operation of these novel service properties.
This document addresses DetNet-specific security considerations from This document addresses DetNet-specific security considerations from
the perspectives of both the DetNet system-level designer and the perspectives of both the DetNet system-level designer and
component designer. System considerations include a threat model, component designer. System considerations include a taxonomy of
taxonomy of relevant attacks, and associations of threats versus use relevant threats and attacks, and associations of threats versus use
cases and service properties. Component-level considerations include cases and service properties. Component-level considerations include
ingress filtering and packet arrival time violation detection. ingress filtering and packet arrival time violation detection.
This document also addresses security considerations specific to the This document also addresses security considerations specific to the
IP and MPLS data plane technologies, thereby complementing the IP and MPLS data plane technologies, thereby complementing the
Security Considerations sections of those documents. Security Considerations sections of those documents.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
skipping to change at page 2, line 4 skipping to change at page 2, line 4
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on June 14, 2021. This Internet-Draft will expire on August 5, 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Abbreviations and Terminology . . . . . . . . . . . . . . . . 6 2. Abbreviations and Terminology . . . . . . . . . . . . . . . . 7
3. Security Considerations for DetNet Component Design . . . . . 7 3. Security Considerations for DetNet Component Design . . . . . 8
3.1. Resource Allocation . . . . . . . . . . . . . . . . . . . 7 3.1. Resource Allocation . . . . . . . . . . . . . . . . . . . 8
3.2. Explicit Routes . . . . . . . . . . . . . . . . . . . . . 8 3.1.1. Inviolable Flows . . . . . . . . . . . . . . . . . . 8
3.3. Redundant Path Support . . . . . . . . . . . . . . . . . 8 3.1.2. Design Trade-Off Considerations in the Use Cases
3.4. Timing (or other) Violation Reporting . . . . . . . . . . 9 Continuum . . . . . . . . . . . . . . . . . . . . . . 9
3.1.3. Documenting the Security Properties of a Component . 10
3.1.4. Fail-Safe Component Behavior . . . . . . . . . . . . 10
3.1.5. Flow Aggregation Example . . . . . . . . . . . . . . 10
3.2. Explicit Routes . . . . . . . . . . . . . . . . . . . . . 11
3.3. Redundant Path Support . . . . . . . . . . . . . . . . . 11
3.4. Timing (or other) Violation Reporting . . . . . . . . . . 12
4. DetNet Security Considerations Compared With DiffServ 4. DetNet Security Considerations Compared With DiffServ
Security Considerations . . . . . . . . . . . . . . . . . . . 10 Security Considerations . . . . . . . . . . . . . . . . . . . 13
5. Security Threats . . . . . . . . . . . . . . . . . . . . . . 11 5. Security Threats . . . . . . . . . . . . . . . . . . . . . . 14
5.1. Threat Model . . . . . . . . . . . . . . . . . . . . . . 11 5.1. Threat Taxonomy . . . . . . . . . . . . . . . . . . . . . 15
5.2. Threat Analysis . . . . . . . . . . . . . . . . . . . . . 12 5.2. Threat Analysis . . . . . . . . . . . . . . . . . . . . . 16
5.2.1. Delay . . . . . . . . . . . . . . . . . . . . . . . . 12 5.2.1. Delay . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2.2. DetNet Flow Modification or Spoofing . . . . . . . . 12 5.2.2. DetNet Flow Modification or Spoofing . . . . . . . . 16
5.2.3. Resource Segmentation (Inter-segment Attack) . . . . 12 5.2.3. Resource Segmentation (Inter-segment Attack)
5.2.4. Packet Replication and Elimination . . . . . . . . . 13 Vulnerability . . . . . . . . . . . . . . . . . . . . 16
5.2.4.1. Replication: Increased Attack Surface . . . . . . 13 5.2.4. Packet Replication and Elimination . . . . . . . . . 17
5.2.4.2. Replication-related Header Manipulation . . . . . 13 5.2.4.1. Replication: Increased Attack Surface . . . . . . 17
5.2.5. Controller Plane . . . . . . . . . . . . . . . . . . 14 5.2.4.2. Replication-related Header Manipulation . . . . . 17
5.2.5.1. Path Choice Manipulation . . . . . . . . . . . . 14 5.2.5. Controller Plane . . . . . . . . . . . . . . . . . . 18
5.2.5.2. Compromised Controller . . . . . . . . . . . . . 14 5.2.5.1. Path Choice Manipulation . . . . . . . . . . . . 18
5.2.6. Reconnaissance . . . . . . . . . . . . . . . . . . . 14 5.2.5.2. Compromised Controller . . . . . . . . . . . . . 18
5.2.7. Time Synchronization Mechanisms . . . . . . . . . . . 15 5.2.6. Reconnaissance . . . . . . . . . . . . . . . . . . . 19
5.3. Threat Summary . . . . . . . . . . . . . . . . . . . . . 15 5.2.7. Time Synchronization Mechanisms . . . . . . . . . . . 19
6. Security Threat Impacts . . . . . . . . . . . . . . . . . . . 16 5.3. Threat Summary . . . . . . . . . . . . . . . . . . . . . 19
6.1. Delay-Attacks . . . . . . . . . . . . . . . . . . . . . . 19 6. Security Threat Impacts . . . . . . . . . . . . . . . . . . . 20
6.1.1. Data Plane Delay Attacks . . . . . . . . . . . . . . 19 6.1. Delay-Attacks . . . . . . . . . . . . . . . . . . . . . . 23
6.1.2. Controller Plane Delay Attacks . . . . . . . . . . . 20 6.1.1. Data Plane Delay Attacks . . . . . . . . . . . . . . 23
6.2. Flow Modification and Spoofing . . . . . . . . . . . . . 20 6.1.2. Controller Plane Delay Attacks . . . . . . . . . . . 23
6.2.1. Flow Modification . . . . . . . . . . . . . . . . . . 20 6.2. Flow Modification and Spoofing . . . . . . . . . . . . . 23
6.2.2. Spoofing . . . . . . . . . . . . . . . . . . . . . . 20 6.2.1. Flow Modification . . . . . . . . . . . . . . . . . . 24
6.2.2.1. Dataplane Spoofing . . . . . . . . . . . . . . . 20 6.2.2. Spoofing . . . . . . . . . . . . . . . . . . . . . . 24
6.2.2.2. Controller Plane Spoofing . . . . . . . . . . . . 21 6.2.2.1. Dataplane Spoofing . . . . . . . . . . . . . . . 24
6.3. Segmentation Attacks (injection) . . . . . . . . . . . . 21 6.2.2.2. Controller Plane Spoofing . . . . . . . . . . . . 24
6.3.1. Data Plane Segmentation . . . . . . . . . . . . . . . 21 6.3. Segmentation Attacks (injection) . . . . . . . . . . . . 24
6.3.2. Controller Plane Segmentation . . . . . . . . . . . . 21 6.3.1. Data Plane Segmentation . . . . . . . . . . . . . . . 25
6.4. Replication and Elimination . . . . . . . . . . . . . . . 22 6.3.2. Controller Plane Segmentation . . . . . . . . . . . . 25
6.4.1. Increased Attack Surface . . . . . . . . . . . . . . 22 6.4. Replication and Elimination . . . . . . . . . . . . . . . 25
6.4.2. Header Manipulation at Elimination Routers . . . . . 22 6.4.1. Increased Attack Surface . . . . . . . . . . . . . . 26
6.5. Control or Signaling Packet Modification . . . . . . . . 22 6.4.2. Header Manipulation at Elimination Routers . . . . . 26
6.6. Control or Signaling Packet Injection . . . . . . . . . . 22 6.5. Control or Signaling Packet Modification . . . . . . . . 26
6.7. Reconnaissance . . . . . . . . . . . . . . . . . . . . . 22 6.6. Control or Signaling Packet Injection . . . . . . . . . . 26
6.8. Attacks on Time Synchronization Mechanisms . . . . . . . 23 6.7. Reconnaissance . . . . . . . . . . . . . . . . . . . . . 26
6.9. Attacks on Path Choice . . . . . . . . . . . . . . . . . 23 6.8. Attacks on Time Synchronization Mechanisms . . . . . . . 27
7. Security Threat Mitigation . . . . . . . . . . . . . . . . . 23 6.9. Attacks on Path Choice . . . . . . . . . . . . . . . . . 27
7.1. Path Redundancy . . . . . . . . . . . . . . . . . . . . . 23 7. Security Threat Mitigation . . . . . . . . . . . . . . . . . 27
7.2. Integrity Protection . . . . . . . . . . . . . . . . . . 24 7.1. Path Redundancy . . . . . . . . . . . . . . . . . . . . . 27
7.3. DetNet Node Authentication . . . . . . . . . . . . . . . 25 7.2. Integrity Protection . . . . . . . . . . . . . . . . . . 28
7.4. Dummy Traffic Insertion . . . . . . . . . . . . . . . . . 26 7.3. DetNet Node Authentication . . . . . . . . . . . . . . . 29
7.5. Encryption . . . . . . . . . . . . . . . . . . . . . . . 26 7.4. Dummy Traffic Insertion . . . . . . . . . . . . . . . . . 30
7.5.1. Encryption Considerations for DetNet . . . . . . . . 27 7.5. Encryption . . . . . . . . . . . . . . . . . . . . . . . 31
7.6. Control and Signaling Message Protection . . . . . . . . 28 7.5.1. Encryption Considerations for DetNet . . . . . . . . 32
7.7. Dynamic Performance Analytics . . . . . . . . . . . . . . 28 7.6. Control and Signaling Message Protection . . . . . . . . 33
7.8. Mitigation Summary . . . . . . . . . . . . . . . . . . . 30 7.7. Dynamic Performance Analytics . . . . . . . . . . . . . . 33
8. Association of Attacks to Use Cases . . . . . . . . . . . . . 32 7.8. Mitigation Summary . . . . . . . . . . . . . . . . . . . 36
8.1. Association of Attacks to Use Case Common Themes . . . . 32 8. Association of Attacks to Use Cases . . . . . . . . . . . . . 37
8.1.1. Sub-Network Layer . . . . . . . . . . . . . . . . . . 32 8.1. Association of Attacks to Use Case Common Themes . . . . 38
8.1.2. Central Administration . . . . . . . . . . . . . . . 33 8.1.1. Sub-Network Layer . . . . . . . . . . . . . . . . . . 38
8.1.3. Hot Swap . . . . . . . . . . . . . . . . . . . . . . 33 8.1.2. Central Administration . . . . . . . . . . . . . . . 38
8.1.4. Data Flow Information Models . . . . . . . . . . . . 34 8.1.3. Hot Swap . . . . . . . . . . . . . . . . . . . . . . 38
8.1.5. L2 and L3 Integration . . . . . . . . . . . . . . . . 34 8.1.4. Data Flow Information Models . . . . . . . . . . . . 39
8.1.6. End-to-End Delivery . . . . . . . . . . . . . . . . . 34 8.1.5. L2 and L3 Integration . . . . . . . . . . . . . . . . 39
8.1.6. End-to-End Delivery . . . . . . . . . . . . . . . . . 40
8.1.7. Replacement for Proprietary Fieldbuses and Ethernet- 8.1.7. Replacement for Proprietary Fieldbuses and Ethernet-
based Networks . . . . . . . . . . . . . . . . . . . 35 based Networks . . . . . . . . . . . . . . . . . . . 40
8.1.8. Deterministic vs Best-Effort Traffic . . . . . . . . 35 8.1.8. Deterministic vs Best-Effort Traffic . . . . . . . . 41
8.1.9. Deterministic Flows . . . . . . . . . . . . . . . . . 36 8.1.9. Deterministic Flows . . . . . . . . . . . . . . . . . 42
8.1.10. Unused Reserved Bandwidth . . . . . . . . . . . . . . 36 8.1.10. Unused Reserved Bandwidth . . . . . . . . . . . . . . 42
8.1.11. Interoperability . . . . . . . . . . . . . . . . . . 36 8.1.11. Interoperability . . . . . . . . . . . . . . . . . . 42
8.1.12. Cost Reductions . . . . . . . . . . . . . . . . . . . 37 8.1.12. Cost Reductions . . . . . . . . . . . . . . . . . . . 43
8.1.13. Insufficiently Secure Components . . . . . . . . . . 37 8.1.13. Insufficiently Secure Components . . . . . . . . . . 43
8.1.14. DetNet Network Size . . . . . . . . . . . . . . . . . 37 8.1.14. DetNet Network Size . . . . . . . . . . . . . . . . . 43
8.1.15. Multiple Hops . . . . . . . . . . . . . . . . . . . . 38 8.1.15. Multiple Hops . . . . . . . . . . . . . . . . . . . . 44
8.1.16. Level of Service . . . . . . . . . . . . . . . . . . 38 8.1.16. Level of Service . . . . . . . . . . . . . . . . . . 44
8.1.17. Bounded Latency . . . . . . . . . . . . . . . . . . . 39 8.1.17. Bounded Latency . . . . . . . . . . . . . . . . . . . 45
8.1.18. Low Latency . . . . . . . . . . . . . . . . . . . . . 39 8.1.18. Low Latency . . . . . . . . . . . . . . . . . . . . . 45
8.1.19. Bounded Jitter (Latency Variation) . . . . . . . . . 39 8.1.19. Bounded Jitter (Latency Variation) . . . . . . . . . 45
8.1.20. Symmetrical Path Delays . . . . . . . . . . . . . . . 39 8.1.20. Symmetrical Path Delays . . . . . . . . . . . . . . . 45
8.1.21. Reliability and Availability . . . . . . . . . . . . 40 8.1.21. Reliability and Availability . . . . . . . . . . . . 46
8.1.22. Redundant Paths . . . . . . . . . . . . . . . . . . . 40 8.1.22. Redundant Paths . . . . . . . . . . . . . . . . . . . 46
8.1.23. Security Measures . . . . . . . . . . . . . . . . . . 40 8.1.23. Security Measures . . . . . . . . . . . . . . . . . . 46
8.2. Summary of Attack Types per Use Case Common Theme . . . . 41 8.2. Summary of Attack Types per Use Case Common Theme . . . . 47
8.3. Security Considerations for OAM Traffic . . . . . . . . . 43 8.3. Security Considerations for OAM Traffic . . . . . . . . . 49
9. DetNet Technology-Specific Threats . . . . . . . . . . . . . 43 9. DetNet Technology-Specific Threats . . . . . . . . . . . . . 49
9.1. IP . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 9.1. IP . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.2. MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . 45 9.2. MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . 51
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 46 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 52
11. Security Considerations . . . . . . . . . . . . . . . . . . . 46 11. Security Considerations . . . . . . . . . . . . . . . . . . . 52
12. Privacy Considerations . . . . . . . . . . . . . . . . . . . 46 12. Privacy Considerations . . . . . . . . . . . . . . . . . . . 52
13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 46 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 53
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 47 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 53
14.1. Normative References . . . . . . . . . . . . . . . . . . 47 14.1. Normative References . . . . . . . . . . . . . . . . . . 53
14.2. Informative References . . . . . . . . . . . . . . . . . 48 14.2. Informative References . . . . . . . . . . . . . . . . . 54
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 52 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 59
1. Introduction 1. Introduction
A DetNet is one that can carry data flows for real-time applications A deterministic IP network (IETF DetNet, [RFC8655]) can carry data
with extremely low data loss rates and bounded latency. The bounds flows for real-time applications with extremely low data loss rates
on latency defined by DetNet and bounded latency. The bounds on latency defined by DetNet (as
([I-D.ietf-detnet-flow-information-model]) include both worst case described in [I-D.ietf-detnet-flow-information-model]) include both
latency (Maximum Latency, Section 5.9.2) and worst case jitter worst case latency (Maximum Latency, Section 5.9.2) and worst case
(Maximum Latency Variation, Section 5.9.3). Deterministic networks jitter (Maximum Latency Variation, Section 5.9.3). Data flows with
have been successfully deployed in real-time Operational Technology deterministic properties are well-established for Ethernet networks
(OT) applications for some years, however such networks are typically (see TSN, [IEEE802.1BA]); DetNet brings these capabilities to the IP
isolated from external access, and thus the security threat from network.
external attackers is low. IETF Deterministic Networking (DetNet,
[RFC8655]) specifies a set of technologies that enable creation of Deterministic IP networks have been successfully deployed in real-
deterministic flows on IP-based networks of potentially wide area (on time Operational Technology (OT) applications for some years, however
the scale of a corporate network), potentially bringing the OT such networks are typically isolated from external access, and thus
network into contact with Information Technology (IT) traffic and the security threat from external attackers is low. An example of
security threats that lie outside of a tightly controlled and bounded such an isolated network is a network deployed within an aircraft,
area (such as the internals of an aircraft). which is "air gapped" from the outside world. DetNet specifies a set
of technologies that enable creation of deterministic flows on IP-
based networks of potentially wide area (on the scale of a corporate
network), potentially merging OT traffic with best-effort
(Information Technology, IT) traffic, and placing OT network
components into contact with IT network components, thereby exposing
the OT traffic and components to security threats that were not
present in an isolated OT network.
These DetNet (OT-type) technologies may not have previously been These DetNet (OT-type) technologies may not have previously been
deployed on a wide area IP-based network that also carries IT deployed on a wide area IP-based network that also carries IT
traffic, and thus can present security considerations that may be new traffic, and thus can present security considerations that may be new
to IP-based wide area network designers; this document provides to IP-based wide area network designers; this document provides
insight into such system-level security considerations. In addition, insight into such system-level security considerations. In addition,
designers of DetNet components (such as routers) face new security- designers of DetNet components (such as routers) face new security-
related challenges in providing DetNet services, for example related challenges in providing DetNet services, for example
maintaining reliable isolation between traffic flows in an maintaining reliable isolation between traffic flows in an
environment where IT traffic co-mingles with critical reserved- environment where IT traffic co-mingles with critical reserved-
skipping to change at page 5, line 25 skipping to change at page 5, line 39
because they were under a separate control system or otherwise because they were under a separate control system or otherwise
isolated from the IT network, for example [ARINC664P7]). Security isolated from the IT network, for example [ARINC664P7]). Security
considerations for OT networks are not a new area, and there are many considerations for OT networks are not a new area, and there are many
OT networks today that are connected to wide area networks or the OT networks today that are connected to wide area networks or the
Internet; this document focuses on the issues that are specific to Internet; this document focuses on the issues that are specific to
the DetNet technologies and use cases. the DetNet technologies and use cases.
Given the above considerations, securing a DetNet starts with a Given the above considerations, securing a DetNet starts with a
scrupulously well-designed and well-managed engineered network scrupulously well-designed and well-managed engineered network
following industry best practices for security at both the data plane following industry best practices for security at both the data plane
and controller plane; this is the assumed starting point for the and controller plane, as well as for any OAM implementation; this is
considerations discussed herein. Such assumptions also depend on the the assumed starting point for the considerations discussed herein.
network components themselves upholding the security-related Such assumptions also depend on the network components themselves
properties that are to be assumed by DetNet system-level designers; upholding the security-related properties that are to be assumed by
for example, the assumption that network traffic associated with a DetNet system-level designers; for example, the assumption that
given flow can never affect traffic associated with a different flow network traffic associated with a given flow can never affect traffic
is only true if the underlying components make it so. Such associated with a different flow is only true if the underlying
properties, which may represent new challenges to component components make it so. Such properties, which may represent new
designers, are also considered herein. challenges to component designers, are also considered herein.
Starting with a "well-managed network" as noted above enables us to
exclude some of the more powerful adversary capabilities from the
Internet Threat Model of BCP 72 ([RFC3552]), such as the ability to
arbitrarily drop or delay any or all traffic. Given this reduced
attacker capability, we can present security considerations based on
attacker capabilities that are more directly relevant to a DetNet.
In this context we view the "traditional" (i.e. non-time-sensitive) In this context we view the "traditional" (i.e. non-time-sensitive)
network design and management aspects of network security as being network design and management aspects of network security as being
primarily concerned with denial-of service prevention, i.e. they must primarily concerned with denial-of service prevention, i.e. they must
ensure that DetNet traffic goes where it's supposed to and that an ensure that DetNet traffic goes where it's supposed to and that an
external attacker can't inject traffic that disrupts the delivery external attacker can't inject traffic that disrupts the delivery
timing assurance of the DetNet. The time-specific aspects of DetNet timing assurance of the DetNet. The time-specific aspects of DetNet
security presented here take up where those "traditional" design and security presented here take up where those "traditional" design and
management aspects leave off. management aspects leave off.
skipping to change at page 6, line 37 skipping to change at page 7, line 14
o Provide explicit routes for DetNet flows that do not dynamically o Provide explicit routes for DetNet flows that do not dynamically
change with the network topology in ways that affect the quality change with the network topology in ways that affect the quality
of service received by the affected flow(s) of service received by the affected flow(s)
o Distribute data from DetNet flow packets over time and/or space to o Distribute data from DetNet flow packets over time and/or space to
ensure delivery of the data in each packet in spite of the loss of ensure delivery of the data in each packet in spite of the loss of
a path. a path.
This document includes sections considering DetNet component design This document includes sections considering DetNet component design
as well as system design. The latter includes threat modeling and as well as system design. The latter includes a taxonomy and
analysis, threat impact and mitigation, and the association of analysis of threats, threat impacts and mitigations, and an
attacks with use cases (based on the Use Case Common Themes section association of attacks with use cases (based on the Use Case Common
of the DetNet Use Cases [RFC8578]). Themes section of the DetNet Use Cases [RFC8578]).
The structure of the threat model and threat analysis sections were This document is based on the premise that there will be a very broad
originally derived from [RFC7384], which also considers time-related range of DetNet applications and use cases, ranging in size scope
security considerations in IP networks. from individual industrial machines to networks that span an entire
country ([RFC8578]). Thus no single set of prescriptions (such as
exactly which mitigation should be applied to which segment of a
DetNet) can be applicable to all of them, and indeed any single one
that we might prescribe would inevitably prove impractical for some
use case, perhaps one that does not even exist at the time of this
writing. Thus we are not prescriptive here - we are stating the
desired end result, with the understanding that most DetNet use cases
will necessarily differ from each other, and there is no "one size
fits all".
2. Abbreviations and Terminology 2. Abbreviations and Terminology
IT: Information Technology (the application of computers to store, IT: Information Technology (the application of computers to store,
study, retrieve, transmit, and manipulate data or information, often study, retrieve, transmit, and manipulate data or information, often
in the context of a business or other enterprise - [IT_DEF]). in the context of a business or other enterprise - [IT_DEF]).
OT: Operational Technology (the hardware and software dedicated to OT: Operational Technology (the hardware and software dedicated to
detecting or causing changes in physical processes through direct detecting or causing changes in physical processes through direct
monitoring and/or control of physical devices such as valves, pumps, monitoring and/or control of physical devices such as valves, pumps,
etc. - [OT_DEF]) etc. - [OT_DEF])
Component: A component of a DetNet system - used here to refer to any Component: A component of a DetNet system - used here to refer to any
hardware or software element of a DetNet which implements DetNet- hardware or software element of a DetNet which implements DetNet-
specific functionality, for example all or part of a router, switch, specific functionality, for example all or part of a router, switch,
or end system. or end system.
Device: Used here to refer to a physical entity controlled by the Device: Used here to refer to a physical entity controlled by the
DetNet, for example a motor. DetNet, for example a motor.
Resource Segmentation Used as a more general form for Network Resource Segmentation: Used as a more general form for Network
Segmentation (the act or practice of splitting a computer network Segmentation (the act or practice of splitting a computer network
into subnetworks, each being a network segment - [RS_DEF]) into subnetworks, each being a network segment - [RS_DEF])
Controller Plane: In DetNet the Controller Plane corresponds to the
aggregation of the Control and Management Planes (see [RFC8655]
section 4.4.2).
3. Security Considerations for DetNet Component Design 3. Security Considerations for DetNet Component Design
This section provides guidance for implementers of components to be
used in a DetNet.
As noted above, DetNet provides resource allocation, explicit routes As noted above, DetNet provides resource allocation, explicit routes
and redundant path support. Each of these has associated security and redundant path support. Each of these has associated security
implications, which are discussed in this section, in the context of implications, which are discussed in this section, in the context of
component design. Detection, reporting and appropriate action in the component design. Detection, reporting and appropriate action in the
case of packet arrival time violations are also discussed. case of packet arrival time violations are also discussed.
3.1. Resource Allocation 3.1. Resource Allocation
3.1.1. Inviolable Flows
A DetNet system security designer relies on the premise that any A DetNet system security designer relies on the premise that any
resources allocated to a resource-reserved (OT-type) flow are resources allocated to a resource-reserved (OT-type) flow are
inviolable, in other words there is no physical possibility within a inviolable; in other words there is no physical possibility within a
DetNet component that resources allocated to a given flow can be DetNet component that resources allocated to a given DetNet flow can
compromised by any type of traffic in the network; this includes both be compromised by any type of traffic in the network; this includes
malicious traffic as well as inadvertent traffic such as might be malicious traffic as well as inadvertent traffic such as might be
produced by a malfunctioning component, for example one made by a produced by a malfunctioning component, or due to interactions
different manufacturer. From a security standpoint, this is a between components that were not sufficiently tested for
critical assumption, for example when designing against DOS attacks. interoperability. From a security standpoint this is a critical
assumption, for example when designing against DOS attacks. In other
words, with correctly designed components and security mechanisms,
one can prevent malicious activities from impacting other resources.
It is the responsibility of the component designer to ensure that However, achieving the goal of absolutely inviolable flows may not be
this condition is met; this implies protection against excess traffic technically or economically feasible for any given use case, given
from adjacent flows, and against compromises to the resource the broad range of possible use cases (e.g. [reference to DetNet Use
allocation/deallocation process, for example through the use of Cases RFC8578]) and their associated security considerations as
traffic shaping and policing. outlined in this document. It can be viewed as a continuum of
security requirements, from isolated ultra-low latency systems that
may have little security vulnerability (such as an industrial
machine) to broadly distributed systems with many possible attack
vectors and OT security concerns (such as a utility network). Given
this continuum, the design principle employed in this document is to
specify the desired end results, without being overly prescriptive in
how the results are achieved, reflecting the understanding that no
individual implementation is likely to be appropriate for every
DetNet use case.
As an example, consider the implementation of Flow Aggregation for 3.1.2. Design Trade-Off Considerations in the Use Cases Continuum
DetNet flows (as discussed in [RFC8938]). In this example say there
are N flows that are to be aggregated, thus the bandwidth resources It is important for the DetNet system designer to understand, for any
of the aggregate flow must be sufficient to contain the sum of the given DetNet use case and its associated security requirements, the
bandwidth reservation for the N flows. However if one of those flows interaction and design trade-offs that inevitably need to be
were to consume more than its individually allocated bandwidth, this reconciled between the desired end results and the DetNet protocols,
could cause starvation of the other flows. Thus simply providing and as well as the DetNet system and component design.
For any given component, as designed for any given use case (or scope
of use cases), it is the responsibility of the component designer to
ensure that the premise of inviolable flows is supported, to the
extent that they deem necessary to support their target use cases.
For example, the component may include traffic shaping and policing
at the ingress, to prevent corrupted or malicious or excessive
packets from entering the network, thereby decreasing the likelihood
that any traffic will interfere with any DetNet OT flow. The
component may include integrity protection for some or all of the
header fields such as those used for flow ID, thereby decreasing the
likelihood that a packet whose flow ID has been compromised might be
directed into a different flow path. The component may verify every
single packet header at every forwarding location, or only at certain
points. In any of these cases the component may use dynamic
performance analytics (Section 7.7) to cause action to be initiated
to address the situation in an appropriate and timely manner, either
at the data plane or controller plane, or both in concert. The
component's software and hardware may include measures to ensure the
integrity of the resource allocation/deallocation process. Other
design aspects of the component may help ensure that the adverse
effects of malicious traffic are more limited, for example by
protecting network control interfaces, or minimizing cascade
failures. The component may include features specific to a given use
case, such as configuration of the response to a given sequential
packet loss count.
Ultimately, due to cost and complexity factors, the security
properties of a component designed for low-cost systems may be (by
design) far inferior to a component with similar intended
functionality, but designed for highly secure or otherwise critical
applications, perhaps at substantially higher cost. Any given
component is designed for some set of use cases and accordingly will
have certain limitations on its security properties and
vulnerabilities. It is thus the responsibility of the system
designer to assure themselves that the components they use in their
design are capable of satisfying their overall system security
requirements.
3.1.3. Documenting the Security Properties of a Component
In order for the system designer to adequately understand the
security related behavior of a given component, the designer of any
component intended for use with DetNet needs to clearly document the
security properties of that component. For example, to address the
case where a corrupted packet in which the flow identification
information is compromised and thus may incidentally match the flow
ID of another ("victim") DetNet flow, resulting in additional
unauthorized traffic on the victim, the documentation might state
that the component employs integrity protection on the flow
identification fields.
3.1.4. Fail-Safe Component Behavior
Even when the security properties of a component are understood and
well specified, if the component malfunctions, for example due to
physical circumstances unpredicted by the component designer, it may
be difficult or impossible to fully prevent malfunction of the
network. The degree to which a component is hardened against various
types of failures is a distinguishing feature of the component and
its design, and the overall system design can only be as strong as
its weakest link.
However, all networks are subject to this level of uncertainty; it is
not unique to DetNet. Having said that, DetNet raises the bar by
changing many added latency scenarios from tolerable annoyances to
unacceptable service violations. That in turn underscores the
importance of system integrity, as well as correct and stable
configuration of the network and its nodes, as discussed in
Section 1.
3.1.5. Flow Aggregation Example
As another example regarding resource allocation implementation,
consider the implementation of Flow Aggregation for DetNet flows (as
discussed in [RFC8938]). In this example say there are N flows that
are to be aggregated, thus the bandwidth resources of the aggregate
flow must be sufficient to contain the sum of the bandwidth
reservation for the N flows. However if one of those flows were to
consume more than its individually allocated bandwidth, this could
cause starvation of the other flows. Thus simply providing and
enforcing the calculated aggregate bandwidth may not be a complete enforcing the calculated aggregate bandwidth may not be a complete
solution - the bandwidth for each individual flow must still be solution - the bandwidth for each individual flow must still be
guaranteed, for example via ingress policing of each flow (i.e. guaranteed, for example via ingress policing of each flow (i.e.
before it is aggregated). Alternatively, if by some other means each before it is aggregated). Alternatively, if by some other means each
flow to be aggregated can be trusted not to exceed its allocated flow to be aggregated can be trusted not to exceed its allocated
bandwidth, the same goal can be achieved. bandwidth, the same goal can be achieved.
3.2. Explicit Routes 3.2. Explicit Routes
The DetNet-specific purpose for constraining the ability of the The DetNet-specific purpose for constraining the ability of the
DetNet to re-route OT traffic is to maintain the specified service DetNet to re-route OT traffic is to maintain the specified service
parameters (such as upper and lower latency boundaries) for a given parameters (such as upper and lower latency boundaries) for a given
flow. For example if the network were to re-route a flow (or some flow. For example if the network were to re-route a flow (or some
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flow. For example if the network were to re-route a flow (or some flow. For example if the network were to re-route a flow (or some
part of a flow) based exclusively on statistical path usage metrics, part of a flow) based exclusively on statistical path usage metrics,
or due to malicious activity, it is possible that the new path would or due to malicious activity, it is possible that the new path would
have a latency that is outside the required latency bounds which were have a latency that is outside the required latency bounds which were
designed into the original TE-designed path, thereby violating the designed into the original TE-designed path, thereby violating the
quality of service for the affected flow (or part of that flow). quality of service for the affected flow (or part of that flow).
However, it is acceptable for the network to re-route OT traffic in However, it is acceptable for the network to re-route OT traffic in
such a way as to maintain the specified latency bounds (and any other such a way as to maintain the specified latency bounds (and any other
specified service properties) for any reason, for example in response specified service properties) for any reason, for example in response
to a runtime component or path failure. From a security standpoint, to a runtime component or path failure.
the system designer relies on the premise that the packets will be
delivered with the specified latency boundaries; thus any component So from a DetNet security standpoint, the DetNet system designer can
that is involved in controlling or implementing any change of the expect that any component designed for use in a DetNet will deliver
initially TE-configured flow routes needs to prevent malicious or the packets within the agreed-upon service parameters. For the
accidental re-routing of OT flows that might adversely affect component designer, this means that in order for a component to
delivering the traffic within the specified service parameters. achieve that expectation, any component that is involved in
controlling or implementing any change of the initially TE-configured
flow routes must prevent re-routing of OT flows (whether malicious or
accidental) which might adversely affect delivering the traffic
within the specified service parameters.
3.3. Redundant Path Support 3.3. Redundant Path Support
The DetNet provision for redundant paths (PREOF) (as defined in the The DetNet provision for redundant paths (PREOF) (as defined in the
DetNet Architecture [RFC8655]) provides the foundation for high DetNet Architecture [RFC8655]) provides the foundation for high
reliablity of a DetNet, by virtually eliminating packet loss (i.e. to reliability of a DetNet, by virtually eliminating packet loss (i.e.
a degree which is implementation-dependent) through hitless redundant to a degree which is implementation-dependent) through hitless
packet delivery. (Note that PREOF is not defined for a DetNet IP redundant packet delivery. Note: At the time of this writing, PREOF
data plane). is not defined for the IP data plane.
It is the responsibility of the system designer to determine the It is the responsibility of the system designer to determine the
level of reliability required by their use case, and to specify level of reliability required by their use case, and to specify
redundant paths sufficient to provide the desired level of redundant paths sufficient to provide the desired level of
reliability (in as much as that reliability can be provided through reliability (in as much as that reliability can be provided through
the use of redundant paths). It is the responsibility of the the use of redundant paths). It is the responsibility of the
component designer to ensure that the relevant PREOF operations are component designer to ensure that the relevant PREOF operations are
executed reliably and securely, to avoid potentially catastrophic executed reliably and securely, to avoid potentially catastrophic
situations for the operational technology relying on them. situations for the operational technology relying on them.
However, note that not all PREOF operations are necessarily However, note that not all PREOF operations are necessarily
implemented in every network; for example a packet re-ordering implemented in every network; for example a packet re-ordering
function may not be necessary if the packets are either not required function may not be necessary if the packets are either not required
to be in order, or if the ordering is performed in some other part of to be in order, or if the ordering is performed in some other part of
the network. the network.
Ideally a redundant path for a flow could be specified from end to Ideally a redundant path for a flow could be specified from end to
end, however given that this is not always possible (as described in end, however given that this is not always possible (as described in
[RFC8655]) the system designer will need to consider the resulting [RFC8655]) the system designer will need to consider the resulting
end-to-end reliability and security resulting from any given end-to-end reliability and security resulting from any given
arrangment of network segments along the path, each of which provides arrangement of network segments along the path, each of which
its individual PREOF implementation and thus its individual level of provides its individual PREOF implementation and thus its individual
reliabiilty and security. level of reliability and security.
At the data plane the implementation of PREOF depends on the correct At the data plane the implementation of PREOF depends on the correct
assignment and interpretation of packet sequence numbers, as well as assignment and interpretation of packet sequence numbers, as well as
the actions taken based on them, such as elimination (including the actions taken based on them, such as elimination (including
elimination of packets with spurious sequence numbers). Thus the elimination of packets with spurious sequence numbers). Thus the
integrity of these values must be maintained by the component as they integrity of these values must be maintained by the component as they
are assigned by the DetNet Data Plane Service sub-layer, and are assigned by the DetNet Data Plane Service sub-layer, and
transported by the Forwarding sub-layer. This is no different than transported by the Forwarding sub-layer. This is no different than
the integrity of the values in any header used by the DetNet (or any the integrity of the values in any header used by the DetNet (or any
other) data plane, and is not unique to redundant paths. The other) data plane, and is not unique to redundant paths. The
integrity protection of header values is technology-dependent; for integrity protection of header values is technology-dependent; for
example, in Layer 2 networks the integrity of the header fields can example, in Layer 2 networks the integrity of the header fields can
be protected by using MACsec [IEEE802.1AE-2018]. Similary, from the be protected by using MACsec [IEEE802.1AE-2018]. Similarly, from the
sequence number injection perspective, it is no different from any sequence number injection perspective, it is no different from any
other protocols that use sequence numbers. other protocols that use sequence numbers. In particular IPSec
Authentication Header ([RFC4302], Sec. 3 Authentication Header (AH)
Processing) provides useful insights.
3.4. Timing (or other) Violation Reporting 3.4. Timing (or other) Violation Reporting
Another fundamental assumption of a secure DetNet is that in any case A task of the DetNet system designer is to create a network such that
in which an incoming packet arrives with any timing or bandwidth for any incoming packet which arrives with any timing or bandwidth
violation, something can be done about it which doesn't cause damage violation, an appropriate action can be taken in order to prevent
to the system. For example having the network shut down a link if a damage to the system. The reporting step may be accomplished through
packet arrives outside of its prescribed time window may serve the dynamic performance analysis (see Section 7.7) or by any other means
attacker better than it serves the network. That means that the data as implemented in one or more components. The action to be taken for
plane of the component must be able to detect and act on a variety of any given circumstance within any given application will depend on
such violations, at least alerting the controller plane. Any action the use case. The action may involve intervention from the
apart from that needs to be carefully considered in the context of controller plane, or it may be taken "immediately" by an individual
the specific system. Some possible violations that warrant detection component, for example if very fast response is required.
include cases where a packet arrives:
The definitions and selections of the actions that can be taken are
properties of the components. The component designer implements
these options according to their expected use cases, which may vary
widely from component to component. Clearly selecting an
inappropriate response to a given condition may cause more problems
than it is intending to mitigate; for example, a naive approach might
be to have the component shut down the link if a packet arrives
outside of its prescribed time window; however such a simplistic
action may serve the attacker better than it serves the network.
Similarly, simple logging of such issues may not be adequate, since a
delay in response could result in material damage, for example to
mechanical devices controlled by the network. Thus a breadth of
possible and effective security-related actions and their
configuration is a positive attribute for a DetNet component.
Some possible violations that warrant detection include cases where a
packet arrives:
o Outside of its prescribed time window o Outside of its prescribed time window
o Within its time window but with a compromised time stamp that o Within its time window but with a compromised time stamp that
makes it appear that it is not within its window makes it appear that it is not within its window
o Exceeding the reserved flow bandwidth o Exceeding the reserved flow bandwidth
Logging of such issues is unlikely to be adequate, since a delay in
response to the situation could result in material damage, for
example to mechanical devices controlled by the network. Given that
the data plane component probably has no knowledge of the use case of
the network, or its applications and end systems, it would seem
useful for a data plane component to allow the system designer to
configure its actions in the face of such violations.
Some possible direct actions that may be taken at the data plane Some possible direct actions that may be taken at the data plane
include traffic policing and shaping functions (e.g., those described include traffic policing and shaping functions (e.g., those described
in [RFC2475]), separating flows into per-flow rate-limited queues, in [RFC2475]), separating flows into per-flow rate-limited queues,
and potentially applying active queue management [RFC7567]. However and potentially applying active queue management [RFC7567]. However
if those (or any other) actions are to be taken, the system designer if those (or any other) actions are to be taken, the system designer
must ensure that the results of such actions do not compromise the must ensure that the results of such actions do not compromise the
continued safe operation of the system. For example, the network continued safe operation of the system. For example, the network
(i.e. the controller plane and data plane working together) must (i.e. the controller plane and data plane working together) must
mitigate in a timely fashion any potential adverse effect on mitigate in a timely fashion any potential adverse effect on
mechanical devices controlled by the network. mechanical devices controlled by the network.
4. DetNet Security Considerations Compared With DiffServ Security 4. DetNet Security Considerations Compared With DiffServ Security
Considerations Considerations
DetNet is designed to be compatible with DiffServ [RFC2474] as DetNet is designed to be compatible with DiffServ [RFC2474] as
applied to IT traffic in the DetNet. DetNet also incorporates the applied to IT traffic in the DetNet. DetNet also incorporates the
use of the 6-bit value of the DSCP field of the TOS field of the IP use of the 6-bit value of the DSCP field of the Type of Service (ToS)
header for flow identification for OT traffic, however the DetNet byte of the IPv4 header (or the Traffic Class byte in IPv6) for flow
interpretation of the DSCP value for OT traffic is not equivalent to identification for OT traffic. However, the DetNet interpretation of
the PHB selection behavior as defined by DiffServ. the DSCP value for OT traffic is not equivalent to the PHB selection
behavior as defined by DiffServ.
Thus security consideration for DetNet have some aspects in common Thus security consideration for DetNet have some aspects in common
with DiffServ, in fact overlapping 100% with respect to IP IT with DiffServ, in fact overlapping 100% with respect to IP IT
traffic. Security considerations for these aspects are part of the traffic. Security considerations for these aspects are part of the
existing literature on IP network security, specifically the Security existing literature on IP network security, specifically the Security
Considerations sections of [RFC2474] and [RFC2475]. However DetNet Considerations sections of [RFC2474] and [RFC2475]. However, DetNet
also introduces timing and other considerations which are not present also introduces timing and other considerations which are not present
in DiffServ, so the DiffServ security considerations are necessary in DiffServ, so the DiffServ security considerations are a subset of
but not sufficient for DetNet. the DetNet security considerations.
In the case of DetNet OT traffic, the DSCP value is interpreted In the case of DetNet OT traffic, the DSCP value is interpreted
differently than in DiffServ and contribute to determination of the differently than in DiffServ and contribute to determination of the
service provided to the packet. In DetNet, there are similar service provided to the packet. In DetNet, there are similar
consequences to DiffServ for lack of detection of, or incorrect consequences to DiffServ for lack of detection of, or incorrect
handling of, packets with mismarked DSCP values, and many of the handling of, packets with mismarked DSCP values, and many of the
points made in the DiffServ Security discussions ([RFC2475] Sec. 6.1 points made in the DiffServ Security discussions ([RFC2475] Sec. 6.1
, [RFC2474] Sec. 7 and [RFC6274] Sec 3.3.2.1) are also relevant to , [RFC2474] Sec. 7 and [RFC6274] Sec 3.3.2.1) are also relevant to
DetNet OT traffic, though perhaps in modified form. For example, in DetNet OT traffic, though perhaps in modified form. For example, in
DetNet the effect of an undetected or incorrectly handled maliciously DetNet the effect of an undetected or incorrectly handled maliciously
mismarked DSCP field in an OT packet is not identical to affecting mismarked DSCP field in an OT packet is not identical to affecting
the PHB of that packet, since DetNet does not use the PHB concept for the PHB of that packet, since DetNet does not use the PHB concept for
OT traffic; but nonetheless the service provided to the packet could OT traffic; but nonetheless the service provided to the packet could
be affected, so mitigation measures analogous to those prescribed by be affected, so mitigation measures analogous to those prescribed by
DiffServ would be appropriate for DetNet. For example, mismarked DiffServ would be appropriate for DetNet. For example, mismarked
DSCP values should not cause failure of network nodes. The remarks DSCP values should not cause failure of network nodes. The remarks
in [RFC2474] regarding IPsec and Tunnelling Interactions are also in [RFC2474] regarding IPsec and Tunnelling Interactions are also
relevant (though this is not to say that other sections are less relevant (though this is not to say that other sections are less
relevant). relevant).
In this discussion, interpretation (and any possible intentional re-
marking) of the DSCP values of packets destined for DetNet OT flows
is expected to occur at the ingress to the DetNet domain; once inside
the domain, maintaining the integrity of the DSCP values is subject
to the same handling considerations as any other field in the packet.
5. Security Threats 5. Security Threats
This section presents a threat model, and analyzes the possible This section presents a taxonomy of threats, and analyzes the
threats in a DetNet-enabled network. The threats considered in this possible threats in a DetNet-enabled network. The threats considered
section are independent of any specific technologies used to in this section are independent of any specific technologies used to
implement the DetNet; Section 9 considers attacks that are associated implement the DetNet; Section 9 considers attacks that are associated
with the DetNet technologies encompassed by [RFC8938]. with the DetNet technologies encompassed by [RFC8938].
We distinguish controller plane threats from data plane threats. The We distinguish controller plane threats from data plane threats. The
attack surface may be the same, but the types of attacks as well as attack surface may be the same, but the types of attacks as well as
the motivation behind them, are different. For example, a delay the motivation behind them, are different. For example, a delay
attack is more relevant to data plane than to controller plane. attack is more relevant to data plane than to controller plane.
There is also a difference in terms of security solutions: the way There is also a difference in terms of security solutions: the way
you secure the data plane is often different than the way you secure you secure the data plane is often different than the way you secure
the controller plane. the controller plane.
5.1. Threat Model 5.1. Threat Taxonomy
The threat model used in this document employs organizational This document employs organizational elements of the threat models of
elements of the threat models of [RFC7384] and [RFC7835]. This model [RFC7384] and [RFC7835]. This model classifies attackers based on
classifies attackers based on two criteria: two criteria:
o Internal vs. external: internal attackers either have access to a o Internal vs. external: internal attackers either have access to a
trusted segment of the network or possess the encryption or trusted segment of the network or possess the encryption or
authentication keys. External attackers, on the other hand, do authentication keys. External attackers, on the other hand, do
not have the keys and have access only to the encrypted or not have the keys and have access only to the encrypted or
authenticated traffic. authenticated traffic.
o On-path vs. off-path: on-path attackers are located in a position o On-path vs. off-path: on-path attackers are located in a position
that allows interception and modification of in-flight protocol that allows interception, modification, or dropping of in-flight
packets, whereas off-path attackers can only attack by generating protocol packets, whereas off-path attackers can only attack by
protocol packets. generating protocol packets.
Regarding the boundary between internal vs. external attackers as
defined above, please note that in this document we do not make
concrete recommendations regarding which specific segments of the
network are to be protected in any specific way, for example via
encryption or authentication. As a result, the boundary as defined
above is not unequivocally specified here. Given that constraint,
the reader can view an internal attacker as one who can operate
within the perimeter defined by the DetNet Edge Nodes (as defined in
the DetNet Architecture [RFC8655]), allowing that the specifics of
what is encrypted or authenticated within this perimeter will vary
depending on the implementation.
Care has also been taken to adhere to Section 5 of [RFC3552], both Care has also been taken to adhere to Section 5 of [RFC3552], both
with respect to which attacks are considered out-of-scope for this with respect to which attacks are considered out-of-scope for this
document, but also which are considered to be the most common threats document, but also which are considered to be the most common threats
(explored further in Section 5.2, Threat Analysis). Most of the (explored further in Section 5.2, Threat Analysis). Most of the
direct threats to DetNet are active attacks (i.e. attacks that modify direct threats to DetNet are active attacks (i.e. attacks that modify
DetNet traffic), but it is highly suggested that DetNet application DetNet traffic), but it is highly suggested that DetNet application
developers take appropriate measures to protect the content of the developers take appropriate measures to protect the content of the
DetNet flows from passive attacks (i.e. attacks that observe but do DetNet flows from passive attacks (i.e. attacks that observe but do
not modify DetNet traffic) for example through the use of TLS or not modify DetNet traffic) for example through the use of TLS or
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5.2.2. DetNet Flow Modification or Spoofing 5.2.2. DetNet Flow Modification or Spoofing
An attacker can modify some header fields of en route packets in a An attacker can modify some header fields of en route packets in a
way that causes the DetNet flow identification mechanisms to way that causes the DetNet flow identification mechanisms to
misclassify the flow. Alternatively, the attacker can inject traffic misclassify the flow. Alternatively, the attacker can inject traffic
that is tailored to appear as if it belongs to a legitimate DetNet that is tailored to appear as if it belongs to a legitimate DetNet
flow. The potential consequence is that the DetNet flow resource flow. The potential consequence is that the DetNet flow resource
allocation cannot guarantee the performance that is expected when the allocation cannot guarantee the performance that is expected when the
flow identification works correctly. flow identification works correctly.
5.2.3. Resource Segmentation (Inter-segment Attack) 5.2.3. Resource Segmentation (Inter-segment Attack) Vulnerability
An attacker can inject traffic that will consume network resources DetNet components are expected to split their resources between
such that it affects DetNet flows. This can be performed using non- DetNet flows in a way that prevents traffic from one DetNet flow from
DetNet traffic that indirectly affects DetNet traffic (hardware affecting the performance of other DetNet flows, and also prevents
resource exhaustion), or by using DetNet traffic from one DetNet flow non-DetNet traffic from affecting DetNet flows. However, perhaps due
that directly affects traffic from different DetNet flows. to implementation constraints, some resources may be partially
shared, and an attacker may try to exploit this property. For
example, an attacker can inject traffic in order to exhaust network
resources such that DetNet packets which share resources with the
injected traffic may be dropped or delayed. Such injected traffic
may be part of DetNet flows or non-DetNet traffic.
Another example of a resource segmentation attack is the case in
which an attacker is able to overload the exception path queue on the
router, i.e. a "slow path" typically taken by control or OAM packets
which are diverted from the data plane because they require
processing by a CPU. DetNet OT flows are typically configured to
take the "fast path" through the data plane, to minimize latency.
However if there is only one queue from the forwarding ASIC to the
exception path, and for some reason the system is configured such
that DetNet packets must be handled on this exception path, then
saturating the exception path could result in delaying or dropping of
DetNet packets.
5.2.4. Packet Replication and Elimination 5.2.4. Packet Replication and Elimination
5.2.4.1. Replication: Increased Attack Surface 5.2.4.1. Replication: Increased Attack Surface
Redundancy is intended to increase the robustness and survivability Redundancy is intended to increase the robustness and survivability
of DetNet flows, and replication over multiple paths can potentially of DetNet flows, and replication over multiple paths can potentially
mitigate an attack that is limited to a single path. However, the mitigate an attack that is limited to a single path. However, the
fact that packets are replicated over multiple paths increases the fact that packets are replicated over multiple paths increases the
attack surface of the network, i.e., there are more points in the attack surface of the network, i.e., there are more points in the
skipping to change at page 13, line 41 skipping to change at page 17, line 39
dropped, thus compromising some of the advantage of path dropped, thus compromising some of the advantage of path
redundancy. redundancy.
o Flow hijacking - an attacker can hijack a DetNet flow with access o Flow hijacking - an attacker can hijack a DetNet flow with access
to a single path by systematically replacing the SNs on the given to a single path by systematically replacing the SNs on the given
path with higher SN values. For example, an attacker can replace path with higher SN values. For example, an attacker can replace
every SN value S with a higher value S+C, where C is a constant every SN value S with a higher value S+C, where C is a constant
integer. Thus, the attacker creates a false illusion that the integer. Thus, the attacker creates a false illusion that the
attacked path has the lowest delay, causing all packets from other attacked path has the lowest delay, causing all packets from other
paths to be eliminated in favor of the attacked path. Once the paths to be eliminated in favor of the attacked path. Once the
flow from the compromised path is favored by the elminating flow from the compromised path is favored by the eliminating
bridge, the flow is hijacked by the attacker. It is now posible bridge, the flow has effectively been hijacked by the attacker.
to either replace en route packets with malicious packets, or It is now possible for the attacker to either replace en route
simply injecting errors, causing the packets to be dropped at packets with malicious packets, or to simply inject errors into
their destination. the packets, causing the packets to be dropped at their
destination.
o Amplification - an attacker who injects packets into a flow that o Amplification - an attacker who injects packets into a flow that
is to be replicated will have their attack amplified through the is to be replicated will have their attack amplified through the
replication process. This is no different than any attacker who replication process. This is no different than any attacker who
injects packets that are delivered through multicast, broadcast, injects packets that are delivered through multicast, broadcast,
or other point-to-multi-point mechanisms. or other point-to-multi-point mechanisms.
5.2.5. Controller Plane 5.2.5. Controller Plane
5.2.5.1. Path Choice Manipulation 5.2.5.1. Path Choice Manipulation
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5.2.5.1.3. Increased Attack Surface 5.2.5.1.3. Increased Attack Surface
One of the possible consequences of a path manipulation attack is an One of the possible consequences of a path manipulation attack is an
increased attack surface. Thus, when the attack described in the increased attack surface. Thus, when the attack described in the
previous subsection is implemented, it may increase the potential of previous subsection is implemented, it may increase the potential of
other attacks to be performed. other attacks to be performed.
5.2.5.2. Compromised Controller 5.2.5.2. Compromised Controller
An attacker can subvert a controller, or enable a compromised An attacker can subvert a legitimate controller (or subvert another
controller to falsely represent itself as a controller so that the component such that it represents itself as a legitimate controller)
network nodes believe it to be authorized to instruct them. with the result that the network nodes incorrectly believe it is
authorized to instruct them.
Presence of compromised nodes in a DetNet is not a new threat that The presence of a compromised node or controller in a DetNet is not a
arises as a result of determinism or time sensitivity; the same threat that arises as a result of determinism or time sensitivity;
techniques used to prevent or mitigate against compromised nodes in the same techniques used to prevent or mitigate against compromised
any network are equally applicable in the DetNet case. However this nodes in any network are equally applicable in the DetNet case. The
underscores the requirement for careful system security design in a act of compromising a controller may not even be within the
DetNet, given that the effects of even one bad actor on the network capabilities of our defined attacker types - in other words it may
can be potentially catastrophic. not be achievable via packet traffic at all, whether internal or
external, on-path or off-path. It might be accomplished for example
by a human with physical access to the component, who could upload
bogus firmware to it via a USB stick. All of this underscores the
requirement for careful overall system security design in a DetNet,
given that the effects of even one bad actor on the network can be
potentially catastrophic.
Security concerns specific to any given controller plane technology Security concerns specific to any given controller plane technology
used in DetNet will be addressed by the DetNet documents associated used in DetNet will be addressed by the DetNet documents associated
with that technology. with that technology.
5.2.6. Reconnaissance 5.2.6. Reconnaissance
A passive eavesdropper can identify DetNet flows and then gather A passive eavesdropper can identify DetNet flows and then gather
information about en route DetNet flows, e.g., the number of DetNet information about en route DetNet flows, e.g., the number of DetNet
flows, their bandwidths, their schedules, or other temporal flows, their bandwidths, their schedules, or other temporal or
properties. The gathered information can later be used to invoke statistical properties. The gathered information can later be used
other attacks on some or all of the flows. to invoke other attacks on some or all of the flows.
DetNet flows are typically uniquely identified by their 6-tuple, i.e. DetNet flows are typically uniquely identified by their 6-tuple, i.e.
fields within the IP header, however in some implementations the flow fields within the L3 or L4 header, however in some implementations
ID may also be augmented by additional per-flow attributes known to the flow ID may also be augmented by additional per-flow attributes
the system, e.g. above the IP-layer. For the purpose of this known to the system, e.g. above L4. For the purpose of this document
document we assume any such additional fields used for flow ID are we assume any such additional fields used for flow ID are encrypted
encrypted and/or integrity-protected from external attackers. and/or integrity-protected from external attackers. Note however
that existing OT protocols designed for use on dedicated secure
networks may not intrinsically provide such protection, in which case
IPsec or transport layer security mechanisms may be needed.
5.2.7. Time Synchronization Mechanisms 5.2.7. Time Synchronization Mechanisms
An attacker can use any of the attacks described in [RFC7384] to An attacker can use any of the attacks described in [RFC7384] to
attack the synchronization protocol, thus affecting the DetNet attack the synchronization protocol, thus affecting the DetNet
service. service.
5.3. Threat Summary 5.3. Threat Summary
A summary of the attacks that were discussed in this section is A summary of the attacks that were discussed in this section is
skipping to change at page 16, line 11 skipping to change at page 20, line 11
under the assumption that a corresponding security mechanism is being under the assumption that a corresponding security mechanism is being
used, and that the corresponding network equipment takes part in this used, and that the corresponding network equipment takes part in this
mechanism. mechanism.
+-------------------------------------------+----+-----+----+-----+ +-------------------------------------------+----+-----+----+-----+
| Attack | Attacker Type | | Attack | Attacker Type |
| +----------+----------+ | +----------+----------+
| | Internal | External | | | Internal | External |
| |On-P|Off-P|On-P|Off-P| | |On-P|Off-P|On-P|Off-P|
+-------------------------------------------+----+-----+----+-----+ +-------------------------------------------+----+-----+----+-----+
|Delay attack | + | + | + | + | |Delay attack | + | | + | |
+-------------------------------------------+----+-----+----+-----+ +-------------------------------------------+----+-----+----+-----+
|DetNet Flow Modification or Spoofing | + | + | | | |DetNet Flow Modification or Spoofing | + | + | | |
+-------------------------------------------+----+-----+----+-----+ +-------------------------------------------+----+-----+----+-----+
|Inter-segment Attack | + | + | + | + | |Inter-segment Attack | + | + | + | + |
+-------------------------------------------+----+-----+----+-----+ +-------------------------------------------+----+-----+----+-----+
|Replication: Increased Attack Surface | + | + | + | + | |Replication: Increased Attack Surface | + | + | + | + |
+-------------------------------------------+----+-----+----+-----+ +-------------------------------------------+----+-----+----+-----+
|Replication-related Header Manipulation | + | | | | |Replication-related Header Manipulation | + | | | |
+-------------------------------------------+----+-----+----+-----+ +-------------------------------------------+----+-----+----+-----+
|Path Manipulation | + | + | | | |Path Manipulation | + | + | | |
skipping to change at page 16, line 38 skipping to change at page 20, line 38
+-------------------------------------------+----+-----+----+-----+ +-------------------------------------------+----+-----+----+-----+
|Reconnaissance | + | | + | | |Reconnaissance | + | | + | |
+-------------------------------------------+----+-----+----+-----+ +-------------------------------------------+----+-----+----+-----+
|Attacks on Time Synchronization Mechanisms | + | + | + | + | |Attacks on Time Synchronization Mechanisms | + | + | + | + |
+-------------------------------------------+----+-----+----+-----+ +-------------------------------------------+----+-----+----+-----+
Figure 1: Threat Analysis Summary Figure 1: Threat Analysis Summary
6. Security Threat Impacts 6. Security Threat Impacts
This section describes and rates the impact of the attacks described When designing security for a DetNet, as with any network, it may be
in Section 5, Security Threats. In this section, the impacts as prohibitively expensive or technically infeasible to thoroughly
described assume that the associated mitigation is not present or has protect against every possible threat. Thus the security designer
failed. Mitigations are discussed in Section 7, Security Threat must be informed (for example by an application domain expert such as
Mitigation. a product manager) regarding the relative significance of the various
threats and their impact if a successful attack is carried out. In
this section we present an example of a possible template for such a
communication, culminating in a table (Figure 2) which lists a set of
threats under consideration, and some values characterizing their
relative impact in the context of a given industry. The specific
threats, industries, and impact values in the table are provided only
as an example of this kind of assessment and its communication; they
are not intended to be taken literally.
This section considers assessment of the relative impacts of the
attacks described in Section 5, Security Threats. In this section,
the impacts as described assume that the associated mitigation is not
present or has failed. Mitigations are discussed in Section 7,
Security Threat Mitigation.
In computer security, the impact (or consequence) of an incident can In computer security, the impact (or consequence) of an incident can
be measured in loss of confidentiality, integrity or availability of be measured in loss of confidentiality, integrity or availability of
information. In the case of time sensitive networks, the impact of a information. In the case of time sensitive or OT networks (though
network exploit can also include failure or malfunction of mechanical not to the exclusion of IT or non-time-sensitive networks) the impact
and/or other OT systems. of an exploit can also include failure or malfunction of mechanical
and/or other physical systems.
DetNet raises these stakes significantly for OT applications, DetNet raises these stakes significantly for OT applications,
particularly those which may have been designed to run in an OT-only particularly those which may have been designed to run in an OT-only
environment and thus may not have been designed for security in an IT environment and thus may not have been designed for security in an IT
environment with its associated components, services and protocols. environment with its associated components, services and protocols.
The extent of impact of a successful vulnerability exploit varies The extent of impact of a successful vulnerability exploit varies
considerably by use case and by industry; additional insights considerably by use case and by industry; additional insights
regarding the individual use cases is available from [RFC8578], regarding the individual use cases is available from [RFC8578],
DetNet Use Cases. Each of those use cases is represented in DetNet Use Cases. Each of those use cases is represented in
Figure 2, including Pro Audio, Electrical Utilities, Industrial M2M Figure 2, including Pro Audio, Electrical Utilities, Industrial M2M
(split into two areas, M2M Data Gathering and M2M Control Loop), and (split into two areas, M2M Data Gathering and M2M Control Loop), and
others. others.
Aspects of Impact (left column) include Criticality of Failure, Aspects of Impact (left column) include Criticality of Failure,
Effects of Failure, Recovery, and DetNet Functional Dependence. Effects of Failure, Recovery, and DetNet Functional Dependence.
Criticality of failure summarizes the seriousness of the impact. The Criticality of failure summarizes the seriousness of the impact. The
impact of a resulting failure can affect many different metrics that impact of a resulting failure can affect many different metrics that
vary greatly in scope and severity. In order to reduce the number of vary greatly in scope and severity. In order to reduce the number of
variables, only the following were included: Financial, Health and variables, only the following were included: Financial, Health and
Safety, People well being (People WB), Affect on a single Safety, Effect on a Single Organization, and Effect on Multiple
organization, and affect on multiple organizations. Recovery Organizations. Recovery outlines how long it would take for an
outlines how long it would take for an affected use case to get back affected use case to get back to its pre-failure state (Recovery time
to its pre-failure state (Recovery time objective, RTO), and how much objective, RTO), and how much of the original service would be lost
of the original service would be lost in between the time of service in between the time of service failure and recovery to original state
failure and recovery to original state (Recovery Point Objective, (Recovery Point Objective, RPO). DetNet dependence maps how much the
RPO). DetNet dependence maps how much the following DetNet service following DetNet service objectives contribute to impact of failure:
objectives contribute to impact of failure: Time dependency, data Time dependency, data integrity, source node integrity, availability,
integrity, source node integrity, availability, latency/jitter. latency/jitter.
The scale of the Impact mappings is low, medium, and high. In some The scale of the Impact mappings is low, medium, and high. In some
use cases there may be a multitude of specific applications in which use cases there may be a multitude of specific applications in which
DetNet is used. For simplicity this section attempts to average the DetNet is used. For simplicity this section attempts to average the
varied impacts of different applications. This section does not varied impacts of different applications. This section does not
address the overall risk of a certain impact which would require the address the overall risk of a certain impact which would require the
likelihood of a failure happening. likelihood of a failure happening.
In practice any such ratings will vary from case to case; the ratings In practice any such ratings will vary from case to case; the ratings
shown here are given as examples. shown here are given as examples.
Table, Part One (of Two) Table
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| | Pro A | Util | Bldg |Wire- | Cell |M2M |M2M | | | Pro A | Util | Bldg |Wire- | Cell |M2M |M2M |
| | | | | less | |Data |Ctrl | | | | | | less | |Data |Ctrl |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Criticality | Med | Hi | Low | Med | Med | Med | Med | | Criticality | Med | Hi | Low | Med | Med | Med | Med |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Effects | Effects
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Financial | Med | Hi | Med | Med | Low | Med | Med | | Financial | Med | Hi | Med | Med | Low | Med | Med |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Health/Safety | Med | Hi | Hi | Med | Med | Med | Med | | Health/Safety | Med | Hi | Hi | Med | Med | Med | Med |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| People WB | Med | Hi | Hi | Low | Hi | Low | Low | | Affects 1 org | Hi | Hi | Med | Hi | Med | Med | Med |
+------------------+-----------------------------------------+-----+
| Effect 1 org | Hi | Hi | Med | Hi | Med | Med | Med |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Effect >1 org | Med | Hi | Low | Med | Med | Med | Med | | Affects >1 org | Med | Hi | Low | Med | Med | Med | Med |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
|Recovery |Recovery
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Recov Time Obj | Med | Hi | Med | Hi | Hi | Hi | Hi | | Recov Time Obj | Med | Hi | Med | Hi | Hi | Hi | Hi |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Recov Point Obj | Med | Hi | Low | Med | Low | Hi | Hi | | Recov Point Obj | Med | Hi | Low | Med | Low | Hi | Hi |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
|DetNet Dependence |DetNet Dependence
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Time Dependency | Hi | Hi | Low | Hi | Med | Low | Hi | | Time Dependency | Hi | Hi | Low | Hi | Med | Low | Hi |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Latency/Jitter | Hi | Hi | Med | Med | Low | Low | Hi | | Latency/Jitter | Hi | Hi | Med | Med | Low | Low | Hi |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Data Integrity | Hi | Hi | Med | Hi | Low | Hi | Low | | Data Integrity | Hi | Hi | Med | Hi | Low | Hi | Hi |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Src Node Integ | Hi | Hi | Med | Hi | Med | Hi | Hi | | Src Node Integ | Hi | Hi | Med | Hi | Med | Hi | Hi |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
| Availability | Hi | Hi | Med | Hi | Low | Hi | Hi | | Availability | Hi | Hi | Med | Hi | Low | Hi | Hi |
+------------------+-----------------------------------------+-----+ +------------------+-----------------------------------------+-----+
Table, Part Two (of Two)
+------------------+--------------------------+
| | Mining | Block | Network |
| | | Chain | Slicing |
+------------------+--------------------------+
| Criticality | Hi | Med | Hi |
+------------------+--------------------------+
| Effects
+------------------+--------------------------+
| Financial | Hi | Hi | Hi |
+------------------+--------------------------+
| Health/Safety | Hi | Low | Med |
+------------------+--------------------------+
| People WB | Hi | Low | Med |
+------------------+--------------------------+
| Effect 1 org | Hi | Hi | Hi |
+------------------+--------------------------+
| Effect >1 org | Hi | Low | Hi |
+------------------+--------------------------+
|Recovery
+------------------+--------------------------+
| Recov Time Obj | Hi | Low | Hi |
+------------------+--------------------------+
| Recov Point Obj | Hi | Low | Hi |
+------------------+--------------------------+
|DetNet Dependence
+------------------+--------------------------+
| Time Dependency | Hi | Low | Hi |
+------------------+--------------------------+
| Latency/Jitter | Hi | Low | Hi |
+------------------+--------------------------+
| Data Integrity | Hi | Hi | Hi |
+------------------+--------------------------+
| Src Node Integ | Hi | Hi | Hi |
+------------------+--------------------------+
| Availability | Hi | Hi | Hi |
+------------------+--------------------------+
Figure 2: Impact of Attacks by Use Case Industry Figure 2: Impact of Attacks by Use Case Industry
The rest of this section will cover impact of the different groups in The rest of this section will cover impact of the different groups in
more detail. more detail.
6.1. Delay-Attacks 6.1. Delay-Attacks
6.1.1. Data Plane Delay Attacks 6.1.1. Data Plane Delay Attacks
Note that 'delay attack' also includes the possibility of a 'negative Note that 'delay attack' also includes the possibility of a 'negative
delay' or early arrival of a packet, or possibly adversely changing delay' or early arrival of a packet, or possibly adversely changing
the timestamp value. the timestamp value.
Delayed messages in a DetNet link can result in the same behavior as Delayed messages in a DetNet link can result in the same behavior as
dropped messages in ordinary networks as the services attached to the dropped messages in ordinary networks, since the services attached to
DetNet flow have strict deterministic requirements. the DetNet flow are likely to have strict delivery time requirements.
For a single path scenario, disruption is a real possibility, whereas For a single path scenario, disruption within the single flow is a
in a multipath scenario, large delays or instabilities in one DetNet real possibility. In a multipath scenario, large delays or
flow can lead to increased buffer and processor resources at the instabilities in one DetNet flow can also lead to increased buffer
eliminating router. and processor resource consumption at the eliminating router.
A data-plane delay attack on a system controlling substantial moving A data-plane delay attack on a system controlling substantial moving
devices, for example in industrial automation, can cause physical devices, for example in industrial automation, can cause physical
damage. For example, if the network promises a bounded latency of damage. For example, if the network promises a bounded latency of
2ms for a flow, yet the machine receives it with 5ms latency, control 2ms for a flow, yet the machine receives it with 5ms latency, control
loop of the machine can become unstable. loop of the machine can become unstable.
6.1.2. Controller Plane Delay Attacks 6.1.2. Controller Plane Delay Attacks
In and of itself, this is not directly a threat to the DetNet In and of itself, this is not directly a threat to the DetNet
skipping to change at page 20, line 25 skipping to change at page 24, line 4
o Failure to deliver, or severely delaying, controller plane o Failure to deliver, or severely delaying, controller plane
messages adding an endpoint to a multicast-group will prevent the messages adding an endpoint to a multicast-group will prevent the
new endpoint from receiving expected frames thus disrupting new endpoint from receiving expected frames thus disrupting
expected behavior. expected behavior.
o Delaying messages removing an endpoint from a group can lead to o Delaying messages removing an endpoint from a group can lead to
loss of privacy as the endpoint will continue to receive messages loss of privacy as the endpoint will continue to receive messages
even after it is supposedly removed. even after it is supposedly removed.
6.2. Flow Modification and Spoofing 6.2. Flow Modification and Spoofing
6.2.1. Flow Modification 6.2.1. Flow Modification
If the contents of a packet header or body can be modified by the If the contents of a packet header or body can be modified by the
attacker, this can cause the packet to be routed incorrectly or attacker, this can cause the packet to be routed incorrectly or
dropped, or the payload to be corrupted or subtly modified. dropped, or the payload to be corrupted or subtly modified. Thus,
the potential impact of a modification attack includes disrupting the
application as well as the network equipment.
6.2.2. Spoofing 6.2.2. Spoofing
6.2.2.1. Dataplane Spoofing 6.2.2.1. Dataplane Spoofing
Spoofing dataplane messages can result in increased resource Spoofing dataplane messages can result in increased resource
consumptions on the routers throughout the network as it will consumptions on the routers throughout the network as it will
increase buffer usage and processor utilization. This can lead to increase buffer usage and processor utilization. This can lead to
resource exhaustion and/or increased delay. resource exhaustion and/or increased delay.
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can be forwarded through the network, using part of the allocated can be forwarded through the network, using part of the allocated
bandwidth. This in turn can cause legitimate messages to be dropped bandwidth. This in turn can cause legitimate messages to be dropped
when the resource budget has been exhausted. when the resource budget has been exhausted.
Finally, the endpoint will have to deal with invalid messages being Finally, the endpoint will have to deal with invalid messages being
delivered to the endpoint instead of (or in addition to) a valid delivered to the endpoint instead of (or in addition to) a valid
message. message.
6.2.2.2. Controller Plane Spoofing 6.2.2.2. Controller Plane Spoofing
A successful controller plane spoofing-attack will potentionally have A successful controller plane spoofing-attack will potentially have
adverse effects. It can do virtually anything from: adverse effects. It can do virtually anything from:
o modifying existing DetNet flows by changing the available o modifying existing DetNet flows by changing the available
bandwidth bandwidth
o add or remove endpoints from a DetNet flow o add or remove endpoints from a DetNet flow
o drop DetNet flows completely o drop DetNet flows completely
o falsely create new DetNet flows (exhaust the systems resources, or o falsely create new DetNet flows (exhaust the systems resources, or
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these false messages to the resource budget of that flow. these false messages to the resource budget of that flow.
In a multipath scenario, injected messages will cause increased In a multipath scenario, injected messages will cause increased
processor utilization in elimination routers. If enough paths are processor utilization in elimination routers. If enough paths are
subject to malicious injection, the legitimate messages can be subject to malicious injection, the legitimate messages can be
dropped. Likewise it can cause an increase in buffer usage. In dropped. Likewise it can cause an increase in buffer usage. In
total, it will consume more resources in the routers than normal, total, it will consume more resources in the routers than normal,
giving rise to a resource exhaustion attack on the routers. giving rise to a resource exhaustion attack on the routers.
If a DetNet flow is interrupted, the end application will be affected If a DetNet flow is interrupted, the end application will be affected
by what is now a non-deterministic flow. by what is now a non-deterministic flow. Note that there are many
possible sources of flow interruptions, for example, but not limited
to, such physical layer conditions as a broken wire or a radio link
which is compromised by interference.
6.3.2. Controller Plane Segmentation 6.3.2. Controller Plane Segmentation
In a successful controller plane segmentation attack, control In a successful controller plane segmentation attack, control
messages are acted on by nodes in the network, unbeknownst to the messages are acted on by nodes in the network, unbeknownst to the
central controller or the network engineer. This has the potential central controller or the network engineer. This has the potential
to: to:
o create new DetNet flows (exhausting resources) o create new DetNet flows (exhausting resources)
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central controller or the network engineer. This has the potential central controller or the network engineer. This has the potential
to: to:
o create new DetNet flows (exhausting resources) o create new DetNet flows (exhausting resources)
o drop existing DetNet flows (denial of service) o drop existing DetNet flows (denial of service)
o add end-stations to a multicast group (loss of privacy) o add end-stations to a multicast group (loss of privacy)
o remove end-stations from a multicast group (reduction of service) o remove end-stations from a multicast group (reduction of service)
o modify the DetNet flow attributes (affecting available bandwidth) o modify the DetNet flow attributes (affecting available bandwidth)
If an attacker can inject control messages without the central
controller knowing, then one or more components in the network may
get into a state that is not expected by the controller. At that
point, if the controller initiates a command, the effect of that
command may not be as expected, since the target of the command may
have started from a different initial state.
6.4. Replication and Elimination 6.4. Replication and Elimination
The Replication and Elimination is relevant only to data plane The Replication and Elimination is relevant only to data plane
messages as controller plane messages are not subject to multipath messages as controller plane messages are not subject to multipath
routing. routing.
6.4.1. Increased Attack Surface 6.4.1. Increased Attack Surface
Covered briefly in Section 6.3, Segmentation Attacks. The impact of an increased attack surface is that it increases the
probability that the network can be exposed to an attacker. This can
facilitate a wide range of specific attacks, and their respective
impacts are discussed in other subsections of this section.
6.4.2. Header Manipulation at Elimination Routers 6.4.2. Header Manipulation at Elimination Routers
Covered briefly in Section 6.3, Segmentation Attacks. This attack can potentially cause DoS to the application that uses
the attacked DetNet flows or to the network equipment that forwards
them. Furthermore, it can allow an attacker to manipulate the
network paths and the behavior of the network layer.
6.5. Control or Signaling Packet Modification 6.5. Control or Signaling Packet Modification
If control packets are subject to manipulation undetected, the If control packets are subject to manipulation undetected, the
network can be severely compromised. network can be severely compromised.
6.6. Control or Signaling Packet Injection 6.6. Control or Signaling Packet Injection
If an attacker can inject control packets undetected, the network can If an attacker can inject control packets undetected, the network can
be severely compromised. be severely compromised.
6.7. Reconnaissance 6.7. Reconnaissance
Of all the attacks, this is one of the most difficult to detect and Of all the attacks, this is one of the most difficult to detect and
counter. Often, an attacker will start out by observing the traffic counter.
going through the network and use the knowledge gathered in this
phase to mount future attacks.
The attacker can, at their leisure, observe over time all aspects of An attacker can, at their leisure, observe over time various aspects
the messaging and signalling, learning the intent and purpose of all of the messaging and signalling, learning the intent and purpose of
traffic flows. At some later date, possibly at an important time in the traffic flows. Then at some later date, possibly at an important
an operational context, the attacker can launch a multi-faceted time in the operational context, they might launch an attack based on
attack, possibly in conjunction with some demand for ransom. that knowledge.
The flow-id in the header of the data plane messages gives an The flow-id in the header of the data plane messages gives an
attacker a very reliable identifier for DetNet traffic, and this attacker a very reliable identifier for DetNet traffic, and this
traffic has a high probability of going to lucrative targets. traffic has a high probability of going to lucrative targets.
Applications which are ported from a private OT network to the higher Applications which are ported from a private OT network to the higher
visibility DetNet environment may need to be adapted to limit visibility DetNet environment may need to be adapted to limit
distinctive flow properties that could make them susceptible to distinctive flow properties that could make them susceptible to
reconnaissance. reconnaissance.
6.8. Attacks on Time Synchronization Mechanisms 6.8. Attacks on Time Synchronization Mechanisms
Attacks on time synchronization mechanisms are addressed in DetNet relies on an underlying time synchronization mechanism, and
[RFC7384]. therefore a compromised synchronization mechanism may cause DetNet
nodes to malfunction. Specifically, DetNet flows may fail to meet
their latency requirements and deterministic behavior, thus causing
DoS to DetNet applications.
6.9. Attacks on Path Choice 6.9. Attacks on Path Choice
This is covered in part in Section 6.3, Segmentation Attacks, and as This is covered in part in Section 6.3, Segmentation Attacks, and as
with Replication and Elimination ( Section 6.4), this is relevant for with Replication and Elimination ( Section 6.4), this is relevant for
DataPlane messages. DataPlane messages.
7. Security Threat Mitigation 7. Security Threat Mitigation
This section describes a set of measures that can be taken to This section describes a set of measures that can be taken to
mitigate the attacks described in Section 5, Security Threats. These mitigate the attacks described in Section 5, Security Threats. These
mitigations should be viewed as a toolset that includes several mitigations should be viewed as a set of tools, any of which can be
different and diverse tools. Each application or system will used individually or in concert. The DetNet component and/or system
typically use a subset of these tools, based on a system-specific and/or application designer can apply these tools, as necessary based
threat analysis. on a system-specific threat analysis.
Some of the technology-specific security considerations and Some of the technology-specific security considerations and
mitigation approaches are further discussed in the DETNET data plane mitigation approaches are further discussed in the DetNet data plane
solution documents, such as [RFC8939], [RFC8938], solution documents, such as [RFC8939], [RFC8938],
[I-D.ietf-detnet-mpls-over-udp-ip], and [I-D.ietf-detnet-mpls-over-udp-ip], and
[I-D.ietf-detnet-ip-over-mpls]. [I-D.ietf-detnet-ip-over-mpls].
7.1. Path Redundancy 7.1. Path Redundancy
Description Description
A DetNet flow that can be forwarded simultaneously over multiple A DetNet flow that can be forwarded simultaneously over multiple
paths. Path replication and elimination [RFC8655] provides paths. Packet replication and elimination [RFC8655] provides
resiliency to dropped or delayed packets. This redundancy resiliency to dropped or delayed packets. This redundancy
improves the robustness to failures and to on-path attacks. Note: improves the robustness to failures and to on-path attacks. Note:
At the time of this writing, PREOF is not defined for the IP data At the time of this writing, PREOF is not defined for the IP data
plane. plane.
Related attacks Related attacks
Path redundancy can be used to mitigate various on-path attacks, Path redundancy can be used to mitigate various on-path attacks,
including attacks described in Section 5.2.1, Section 5.2.2, including attacks described in Section 5.2.1, Section 5.2.2,
Section 5.2.3, and Section 5.2.7. However it is also possible Section 5.2.3, and Section 5.2.7. However it is also possible
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A delay modulation attack could result in extensively exercising A delay modulation attack could result in extensively exercising
parts of the code that wouldn't normally be extensively exercised parts of the code that wouldn't normally be extensively exercised
and thus might expose flaws in the system that might otherwise not and thus might expose flaws in the system that might otherwise not
be exposed. be exposed.
7.2. Integrity Protection 7.2. Integrity Protection
Description Description
Integrity Protection in the scope of DetNet is the ability to Integrity Protection in the scope of DetNet is the ability to
detect if a header has been modified (either maliciously or by detect if a packet header has been modified (maliciously or
chance) and propagate a warning to a responsible monitoring agent. otherwise) and if so, take some appropriate action (as discussed
An integrity protection mechanism is designed to counteract header in Section 7.7). The decision on where in the network to apply
modification attacks where a Message Authentication Code (MAC) is integrity protection is part of the DetNet system design, and the
the most common. The MAC can be distributed either in-line implementation of the protection method itself is a part of a
(included in the same packet) or via a side channel. Due to the DetNet component design.
nature of DetNet traffic. Note: a sideband approach may yield too
high overhead and complexity and should only be used as a very The most common technique for detecting header modification is the
last resort if in-line approaches are not viable. use of a Message Authentication Code (MAC) (for examples see
Section 9). The MAC can be distributed either in-line (included
in the same packet) or via a side channel. Of these, the in-line
method is generally preferred due to the low latency that may be
required on DetNet flows and the relative complexity and
computational overhead of a sideband approach.
There are different levels of security available for integrity There are different levels of security available for integrity
protection, ranging from the basic ability to detect if a header protection, ranging from the basic ability to detect if a header
has been corrupted in transit (no malicious attack) to stopping a has been corrupted in transit (no malicious attack) to stopping a
skilled and determined attacker capable of both subtly modifying skilled and determined attacker capable of both subtly modifying
fields in the headers as well as updating an unsigned MAC. Common fields in the headers as well as updating an unsigned MAC. Common
for all are the 2 steps that need to be performed in both ends. for all are the 2 steps that need to be performed in both ends.
The first is computing the checksum or MAC. The corresponding The first is computing the checksum or MAC. The corresponding
verification step must perform the same steps before comparing the verification step must perform the same steps before comparing the
provided with the computed value. Only then can the receiver be provided with the computed value. Only then can the receiver be
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The most basic protection mechanism consists of computing a simple The most basic protection mechanism consists of computing a simple
checksum of the header fields and provide it to the next entity in checksum of the header fields and provide it to the next entity in
the packets path for verification. Using a MAC combined with a the packets path for verification. Using a MAC combined with a
secret key provides the best protection against modification and secret key provides the best protection against modification and
replication attacks (see Section 5.2.2 and Section 5.2.4). This replication attacks (see Section 5.2.2 and Section 5.2.4). This
MAC usage needs to be part of a security association that is MAC usage needs to be part of a security association that is
established and managed by a security association protocol (such established and managed by a security association protocol (such
as IKEv2 for IPsec security associations). Integrity protection as IKEv2 for IPsec security associations). Integrity protection
in the controller plane is discussed in Section 7.6. The secret in the controller plane is discussed in Section 7.6. The secret
key, regardless of MAC used, must be protected from falling into key, regardless of MAC used, must be protected from falling into
the hands of unauthorized users. the hands of unauthorized users. Once key management becomes a
topic, it is important to understand that this is a delicate
process and should not be undertaken lightly. BCP 107 [RFC4107]
provides best practices in this regard.
DetNet system- and/or component- level designers need to be aware DetNet system and/or component designers need to be aware of these
of these distinctions and enforce appropriate integrity protection distinctions and enforce appropriate integrity protection
mechanisms as needed based on a threat analysis. Note that adding mechanisms as needed based on a threat analysis. Note that adding
integrity protection mechanisms may introduce latency, thus many integrity protection mechanisms may introduce latency, thus many
of the same considerations in Section 7.5.1 also apply here. of the same considerations in Section 7.5.1 also apply here.
Packet Sequence Number Integrity Considerations Packet Sequence Number Integrity Considerations
The use of PREOF in a DetNet implementation implies the use of a The use of PREOF in a DetNet implementation implies the use of a
sequence number for each packet. There is a trust relationship sequence number for each packet. There is a trust relationship
between the component that adds the sequence number and the between the component that adds the sequence number and the
component that removes the sequence number. The sequence number component that removes the sequence number. The sequence number
may be end-to-end source to destination, or may be added/deleted may be end-to-end source to destination, or may be added/deleted
by network edge components. The adder and remover(s) have the by network edge components. The adder and remover(s) have the
trust relationship because they are the ones that ensure that the trust relationship because they are the ones that ensure that the
sequence numbers are not modifiable. Thus, sequence numbers can sequence numbers are not modifiable. Thus, sequence numbers can
be protected by using encryption, or by a MAC without using be protected by using authenticated encryption, or by a MAC
encryption. Between the adder and remover there may or may not be without using encryption. Between the adder and remover there may
replication and elimination functions. The elimination functions or may not be replication and elimination functions. The
must be able to see the sequence numbers. Therefore, if elimination functions must be able to see the sequence numbers.
encryption is done between adders and removers it must not obscure Therefore, if encryption is done between adders and removers it
the sequence number. If the sequence removers and the eliminators must not obscure the sequence number. If the sequence removers
are in the same physical component, it may be possible to obscure and the eliminators are in the same physical component, it may be
the sequence number, however that is a layer violation, and is not possible to obscure the sequence number, however that is a layer
recommended practice. Note: At the time of this writing, PREOF is violation, and is not recommended practice. Note: At the time of
not defined for the IP data plane. this writing, PREOF is not defined for the IP data plane.
Related attacks Related attacks
Integrity protection mitigates attacks related to modification and Integrity protection mitigates attacks related to modification and
tampering, including the attacks described in Section 5.2.2 and tampering, including the attacks described in Section 5.2.2 and
Section 5.2.4. Section 5.2.4.
7.3. DetNet Node Authentication 7.3. DetNet Node Authentication
Description Description
Authentication verifies the identity of DetNet nodes (including Authentication verifies the identity of DetNet nodes (including
DetNet Controller Plane nodes), and this enables mitigation of DetNet Controller Plane nodes), and this enables mitigation of
spoofing attacks. While integrity protection ( Section 7.2) spoofing attacks. While integrity protection ( Section 7.2)
prevents intermediate nodes from modifying information, prevents intermediate nodes from modifying information,
authentication (such as IPsec [RFC4301] or MACsec authentication can provide traffic origin verification, i.e. to
[IEEE802.1AE-2018]) can provide traffic origin verification, i.e. verify that each packet in a DetNet flow is from a known source.
to verify that each packet in a DetNet flow is from a known Although node authentication and integrity protection are two
source. different goals of a security protocol, in most cases a common
protocol (such as IPsec [RFC4301] or MACsec [IEEE802.1AE-2018]) is
used for achieving both purposes.
Related attacks Related attacks
DetNet node authentication is used to mitigate attacks related to DetNet node authentication is used to mitigate attacks related to
spoofing, including the attacks of Section 5.2.2, and spoofing, including the attacks of Section 5.2.2, and
Section 5.2.4. Section 5.2.4.
7.4. Dummy Traffic Insertion 7.4. Dummy Traffic Insertion
Description Description
With some queueing methods such as [IEEE802.1Qch-2017] it is With some queueing methods such as [IEEE802.1Qch-2017] it is
possible to introduce dummy traffic in order to regularize the possible to introduce dummy traffic in order to regularize the
timing of packet transmission. timing of packet transmission. This will subsequently reduce the
value of passive monitoring from internal threats (see Section 5)
as it will be much more difficult to associate discrete events
with particular network packets.
Related attacks Related attacks
Removing distinctive temporal properties of individual packets or Removing distinctive temporal properties of individual packets or
flows can be used to mitigate against reconnaissance attacks flows can be used to mitigate against reconnaissance attacks
Section 5.2.6. For example, dummy traffic can be used to Section 5.2.6. For example, dummy traffic can be used to
synthetically maintain constant traffic rate even when no user synthetically maintain constant traffic rate even when no user
data is transmitted, thus making it difficult to collect data is transmitted, thus making it difficult to collect
information about the times at which users are active, and the information about the times at which users are active, and the
times at which DETNET flows are added or removed. times at which DetNet flows are added or removed.
Traffic Insertion Challenges
Once an attacker is able to monitor the frames traversing a
network to such a degree that they can differentiate between best-
effort traffic and traffic belonging to a specific DetNet flow, it
becomes difficult to not reveal to the attacker whether a given
frame is valid traffic or an inserted frame. Thus, having the
DetNet components generate and remove the dummy traffic may or may
not be a viable option, unless certain challenges are solved; for
example, but not limited to:
o Inserted traffic must be indistinguishable from valid stream
traffic from the viewpoint of the attacker.
o DetNet components must be able to safely identify and remove all
inserted traffic (and only inserted traffic).
o The controller plane must manage where to insert and remove dummy
traffic, but this information must not be revealed to an attacker.
An alternative design is to have the insertion and removal of
dummy traffic be performed at the application layer, rather than
by the DetNet itself. Further discussions and reading about how
sRTP handles this can be found in [RFC6562]
7.5. Encryption 7.5. Encryption
Description Description
Reconnaissance attacks (Section 5.2.6) can be mitigated by using Reconnaissance attacks (Section 5.2.6) can be mitigated to some
encryption. Specific encryption protocols will depend on the extent through the use of encryption, thereby preventing the
lower layers that DetNet is forwarded over. For example, IP flows attacker from accessing the packet header or contents. Specific
may be forwarded over IPsec [RFC4301], and Ethernet flows may be encryption protocols will depend on the lower layers that DetNet
secured using MACsec [IEEE802.1AE-2018]. is forwarded over. For example, IP flows may be forwarded over
IPsec [RFC4301], and Ethernet flows may be secured using MACsec
[IEEE802.1AE-2018].
However, despite the use of encryption, a reconnaissance attack
can provide the attacker with insight into the network, even
without visibility into the packet. For example, an attacker can
observe which nodes are communicating with which other nodes,
including when, how often, and with how much data. In addition,
the timing of packets may be correlated in time with external
events such as action of an external device. Such information may
be used by the attacker, for example in mapping out specific
targets for a different type of attack at a different time.
DetNet nodes do not have any need to inspect the payload of any DetNet nodes do not have any need to inspect the payload of any
DetNet packets, making them data-agnostic. This means that end- DetNet packets, making them data-agnostic. This means that end-
to-end encryption at the application layer is an acceptable way to to-end encryption at the application layer is an acceptable way to
protect user data. protect user data.
Note that reconnaissance is a threat that is not specific to Note that reconnaissance is a threat that is not specific to
DetNet flows, and therefore reconnaissance mitigation will DetNet flows, and therefore reconnaissance mitigation will
typically be analyzed and addressed by a network operator typically be analyzed and provided by a network operator
regardless of whether DetNet flows are deployed. Thus, encryption regardless of whether DetNet flows are deployed. Thus, encryption
requirements will typically not be defined in DetNet technology- requirements will typically not be defined in DetNet technology-
specific specifications, but considerations of using DetNet in specific specifications, but considerations of using DetNet in
encrypted environments will be discussed in these specifications. encrypted environments will be discussed in these specifications.
For example, Section 5.1.2.3. of [RFC8939] discusses flow For example, Section 5.1.2.3. of [RFC8939] discusses flow
identification of DetNet flows running over IPsec. identification of DetNet flows running over IPsec.
Related attacks Related attacks
As noted above, encryption can be used to mitigate reconnaissance As noted above, encryption can be used to mitigate reconnaissance
attacks ( Section 5.2.6). However, for a DetNet to provide attacks ( Section 5.2.6). However, for a DetNet to provide
differentiated quality of service on a flow-by-flow basis, the differentiated quality of service on a flow-by-flow basis, the
network must be able to identify the flows individually. This network must be able to identify the flows individually. This
implies that in a reconnaissance attack the attacker may also be implies that in a reconnaissance attack the attacker may also be
able to track individual flows to learn more about the system. able to track individual flows to learn more about the system.
7.5.1. Encryption Considerations for DetNet 7.5.1. Encryption Considerations for DetNet
Any compute time which is required for encryption and decryption Any compute time which is required for encryption and decryption
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network must be able to identify the flows individually. This network must be able to identify the flows individually. This
implies that in a reconnaissance attack the attacker may also be implies that in a reconnaissance attack the attacker may also be
able to track individual flows to learn more about the system. able to track individual flows to learn more about the system.
7.5.1. Encryption Considerations for DetNet 7.5.1. Encryption Considerations for DetNet
Any compute time which is required for encryption and decryption Any compute time which is required for encryption and decryption
processing ('crypto') must be included in the flow latency processing ('crypto') must be included in the flow latency
calculations. Thus, crypto algorithms used in a DetNet must have calculations. Thus, crypto algorithms used in a DetNet must have
bounded worst-case execution times, and these values must be used in bounded worst-case execution times, and these values must be used in
the latency calculations. the latency calculations. Fortunately, encryption and decryption
operations typically are designed to have constant execution times,
in order to avoid side channel leakage.
Some crypto algorithms are symmetric in encode/decode time (such as Some crypto algorithms are symmetric in encode/decode time (such as
AES) and others are asymmetric (such as public key algorithms). AES) and others are asymmetric (such as public key algorithms).
There are advantages and disadvantages to the use of either type in a There are advantages and disadvantages to the use of either type in a
given DetNet context. The discussion in this document relates to the given DetNet context. The discussion in this document relates to the
timing implications of crypto for DetNet; it is assumed that timing implications of crypto for DetNet; it is assumed that
integrity considerations are covered elsewhere in the literature. integrity considerations are covered elsewhere in the literature.
Asymmetrical crypto is typically not used in networks on a packet-by- Asymmetrical crypto is typically not used in networks on a packet-by-
packet basis due to its computational cost. For example, if only packet basis due to its computational cost. For example, if only
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node for every packet. However, this is more computationally node for every packet. However, this is more computationally
expensive. expensive.
In either case, origin verification also requires replay detection as In either case, origin verification also requires replay detection as
part of the security protocol to prevent an attacker from recording part of the security protocol to prevent an attacker from recording
and resending traffic, e.g., as a denial of service attack on flow and resending traffic, e.g., as a denial of service attack on flow
forwarding resources. forwarding resources.
If crypto keys are to be regenerated over the duration of the flow If crypto keys are to be regenerated over the duration of the flow
then the time required to accomplish this must be accounted for in then the time required to accomplish this must be accounted for in
the latency calculations. the latency calculations. Unfortunately, key generation is a
cryptographic operation that is frequently not possible to implement
in constant time, most notably (though not exclusively) for RSA key
pairs.
7.6. Control and Signaling Message Protection 7.6. Control and Signaling Message Protection
Description Description
Control and signaling messages can be protected through the use of Control and signaling messages can be protected through the use of
any or all of encryption, authentication, and integrity protection any or all of encryption, authentication, and integrity protection
mechanisms. mechanisms. Compared with data-flows, the timing constraints for
controller and signaling messages may be less strict, and the
number of such packets may be fewer. If that is the case in a
given application, then it may enable the use of asymmetric
cryptography for signing of both payload and headers for such
messages, as well as encrypting the payload. Given that a DetNet
is managed by a central controller, the use of a shared public key
approach for these processes is well-proven. This is further
discussed in Section 7.5.1.
Related attacks Related attacks
These mechanisms can be used to mitigate various attacks on the These mechanisms can be used to mitigate various attacks on the
controller plane, as described in Section 5.2.5, Section 5.2.7 and controller plane, as described in Section 5.2.5, Section 5.2.7 and
Section 5.2.5.1. Section 5.2.5.1.
7.7. Dynamic Performance Analytics 7.7. Dynamic Performance Analytics
Description Description
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both directions, in order to arrive at a given performance both directions, in order to arrive at a given performance
indicator value. indicator value.
Notification Mechanisms Notification Mechanisms
Making DPA measurement results available at the right place(s) and Making DPA measurement results available at the right place(s) and
time(s) to effect timely response can be challenging. Two time(s) to effect timely response can be challenging. Two
notification mechanisms that are in general use are Netconf/YANG notification mechanisms that are in general use are Netconf/YANG
Notifications (e.g. [RFC5880]) and the proprietary local Notifications (e.g. [RFC5880]) and the proprietary local
telemetry interfaces provided with components from some vendors. telemetry interfaces provided with components from some vendors.
The CoAP Observe Option ([RFC7641]) could also be relevant to such
scenarios.
At the time of this writing YANG Notifications are not addressed At the time of this writing YANG Notifications are not addressed
by the DetNet YANG drafts, however this may be a topic for future by the DetNet YANG drafts, however this may be a topic for future
work. It is possible that some of the passive mechanisms could be work. It is possible that some of the passive mechanisms could be
covered by notifications from non-DetNet-specific YANG modules; covered by notifications from non-DetNet-specific YANG modules;
for example if there is OAM or other performance monitoring that for example if there is OAM or other performance monitoring that
can monitor delay bounds then that could have its own associated can monitor delay bounds then that could have its own associated
YANG model which could be relevant to DetNet, for example some YANG model which could be relevant to DetNet, for example some
"threshold" values for timing measurement notifications. "threshold" values for timing measurement notifications.
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Working Group (rmonmib). See also [RFC6632], An Overview of the Working Group (rmonmib). See also [RFC6632], An Overview of the
IETF Network Management Standards. IETF Network Management Standards.
Vendor-specific local telemetry may be available on some Vendor-specific local telemetry may be available on some
commercially available systems, whereby the system can be commercially available systems, whereby the system can be
programmed (via a proprietary dedicated port and API) to monitor programmed (via a proprietary dedicated port and API) to monitor
and report on specific conditions, based on both passive and and report on specific conditions, based on both passive and
active measurements. active measurements.
Related attacks Related attacks
Performance analytics can be used to detect various attacks,
Performance analytics can be used to mitigate various attacks,
including the ones described in Section 5.2.1 (Delay Attack), including the ones described in Section 5.2.1 (Delay Attack),
Section 5.2.3 (Resource Segmentation Attack), and Section 5.2.7 Section 5.2.3 (Resource Segmentation Attack), and Section 5.2.7
(Time Synchronization Attack). (Time Synchronization Attack). Once detection and notification
have occurred, the appropriate action can be taken to mitigate the
threat.
For example, in the case of data plane delay attacks, one possible For example, in the case of data plane delay attacks, one possible
mitigation is to timestamp the data at the source, and timestamp mitigation is to timestamp the data at the source, and timestamp
it again at the destination, and if the resulting latency exceeds it again at the destination, and if the resulting latency does not
the promised bound, take appropriate action. Note that DetNet meet the service agreement, take appropriate action. Note that
specifies packet sequence numbering, however it does not specify DetNet specifies packet sequence numbering, however it does not
use of packet timestamps, although they may be used by the specify use of packet timestamps, although they may be used by the
underlying transport (for example TSN, [IEEE802.1BA]) to provide underlying transport (for example TSN, [IEEE802.1BA]) to provide
the service. the service.
7.8. Mitigation Summary 7.8. Mitigation Summary
The following table maps the attacks of Section 5, Security Threats, The following table maps the attacks of Section 5, Security Threats,
to the impacts of Section 6, Security Threat Impacts, and to the to the impacts of Section 6, Security Threat Impacts, and to the
mitigations of the current section. Each row specifies an attack, mitigations of the current section. Each row specifies an attack,
the impact of this attack if it is successfully implemented, and the impact of this attack if it is successfully implemented, and
possible mitigation methods. possible mitigation methods.
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| |-Data disruption |-DetNet Node | | |-Data disruption |-DetNet Node |
| | | authentication | | | | authentication |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
|Inter-Segment Attack |-Increased resource |-Path redundancy | |Inter-Segment Attack |-Increased resource |-Path redundancy |
| | consumption |-Performance | | | consumption |-Performance |
| |-Data disruption | analytics | | |-Data disruption | analytics |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
|Replication: Increased|-All impacts of other|-Integrity protection| |Replication: Increased|-All impacts of other|-Integrity protection|
|attack surface | attacks |-DetNet Node | |attack surface | attacks |-DetNet Node |
| | | authentication | | | | authentication |
| | |-Encryption |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
|Replication-related |-Non-deterministic |-Integrity protection| |Replication-related |-Non-deterministic |-Integrity protection|
|Header Manipulation | delay |-DetNet Node | |Header Manipulation | delay |-DetNet Node |
| |-Data disruption | authentication | | |-Data disruption | authentication |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
|Path Manipulation |-Enabler for other |-Control message | |Path Manipulation |-Enabler for other |-Control and |
| | attacks | protection | | | attacks | signaling message |
| | | protection |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
|Path Choice: Increased|-All impacts of other|-Control message | |Path Choice: Increased|-All impacts of other|-Control and |
|Attack Surface | attacks | protection | |Attack Surface | attacks | signaling message |
| | | protection |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
|Control or Signaling |-Increased resource |-Control message | |Control or Signaling |-Increased resource |-Control and |
|Packet Modification | consumption | protection | |Packet Modification | consumption | signaling message |
| |-Non-deterministic | | | |-Non-deterministic | protection |
| | delay | | | | delay | |
| |-Data disruption | | | |-Data disruption | |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
|Control or Signaling |-Increased resource |-Control message | |Control or Signaling |-Increased resource |-Control and |
|Packet Injection | consumption | protection | |Packet Injection | consumption | signaling message |
| |-Non-deterministic | | | |-Non-deterministic | protection |
| | delay | | | | delay | |
| |-Data disruption | | | |-Data disruption | |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
|Attacks on Time |-Non-deterministic |-Path redundancy | |Attacks on Time |-Non-deterministic |-Path redundancy |
|Synchronization | delay |-Control message | |Synchronization | delay |-Control and |
|Mechanisms |-Increased resource | protection | |Mechanisms |-Increased resource | signaling message |
| | consumption |-Performance | | | consumption | protection |
| |-Data disruption | analytics | | |-Data disruption |-Performance |
| | | analytics |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
Figure 3: Mapping Attacks to Impact and Mitigations Figure 3: Mapping Attacks to Impact and Mitigations
8. Association of Attacks to Use Cases 8. Association of Attacks to Use Cases
Different attacks can have different impact and/or mitigation Different attacks can have different impact and/or mitigation
depending on the use case, so we would like to make this association depending on the use case, so we would like to make this association
in our analysis. However since there is a potentially unbounded list in our analysis. However since there is a potentially unbounded list
of use cases, we categorize the attacks with respect to the common of use cases, we categorize the attacks with respect to the common
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A DetNet network can be controlled by a centralized network A DetNet network can be controlled by a centralized network
configuration and control system. Such a system may be in a single configuration and control system. Such a system may be in a single
central location, or it may be distributed across multiple control central location, or it may be distributed across multiple control
entities that function together as a unified control system for the entities that function together as a unified control system for the
network. network.
All attacks named in this document which are relevant to controller All attacks named in this document which are relevant to controller
plane packets (and the controller itself) are relevant to this theme, plane packets (and the controller itself) are relevant to this theme,
including Path Manipulation, Path Choice, Control Packet Modification including Path Manipulation, Path Choice, Control Packet Modification
or Injection, Reconaissance and Attacks on Time Synchronization or Injection, Reconnaissance and Attacks on Time Synchronization
Mechanisms. Mechanisms.
8.1.3. Hot Swap 8.1.3. Hot Swap
A DetNet network is not expected to be "plug and play" - it is A DetNet network is not expected to be "plug and play" - it is
expected that there is some centralized network configuration and expected that there is some centralized network configuration and
control system. However, the ability to "hot swap" components (e.g. control system. However, the ability to "hot swap" components (e.g.
due to malfunction) is similar enough to "plug and play" that this due to malfunction) is similar enough to "plug and play" that this
kind of behavior may be expected in DetNet networks, depending on the kind of behavior may be expected in DetNet networks, depending on the
implementation. implementation.
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This implies that an attack such as Flow Modification, Spoofing or This implies that an attack such as Flow Modification, Spoofing or
Inter-segment (which could introduce packets from a "new" component, Inter-segment (which could introduce packets from a "new" component,
i.e. one heretofore unknown on the network) could be used to exploit i.e. one heretofore unknown on the network) could be used to exploit
the need to consider such packets (as opposed to rejecting them out the need to consider such packets (as opposed to rejecting them out
of hand as one would do if one did not have to consider introduction of hand as one would do if one did not have to consider introduction
of a new component). of a new component).
To mitigate this situation, deployments should provide a method for To mitigate this situation, deployments should provide a method for
dynamic and secure registration of new components, and (possibly dynamic and secure registration of new components, and (possibly
manual) deregistration of retired components. This would avoid the manual) deregistration and re-keying of retired components. This
situation in which the network must accommodate potentially insecure would avoid the situation in which the network must accommodate
packet flows from unknown components. potentially insecure packet flows from unknown components.
Similarly if the network was designed to support runtime replacement Similarly if the network was designed to support runtime replacement
of a clock component, then presence (or apparent presence) and thus of a clock component, then presence (or apparent presence) and thus
consideration of packets from a new such component could affect the consideration of packets from a new such component could affect the
network, or the time synchronization of the network, for example by network, or the time synchronization of the network, for example by
initiating a new Best Master Clock selection process. These types of initiating a new Best Master Clock selection process. These types of
attacks should therefore be considered when designing hot swap type attacks should therefore be considered when designing hot swap type
functionality (see [RFC7384]). functionality (see [RFC7384]).
8.1.4. Data Flow Information Models 8.1.4. Data Flow Information Models
DetNet specifies new YANG models which may present new attack DetNet specifies new YANG models ([I-D.ietf-detnet-yang])which may
surfaces. Per IETF guidelines, security considerations for any YANG present new attack surfaces. Per IETF guidelines, security
model are expected to be part of the YANG model specification, as considerations for any YANG model are expected to be part of the YANG
described in [IETF_YANG_SEC]. model specification, as described in [IETF_YANG_SEC].
8.1.5. L2 and L3 Integration 8.1.5. L2 and L3 Integration
A DetNet network integrates Layer 2 (bridged) networks (e.g. AVB/TSN A DetNet network integrates Layer 2 (bridged) networks (e.g. AVB/TSN
LAN) and Layer 3 (routed) networks (e.g. IP) via the use of well- LAN) and Layer 3 (routed) networks (e.g. IP) via the use of well-
known protocols such as IP, MPLS Pseudowire, and Ethernet. Various known protocols such as IP, MPLS Pseudowire, and Ethernet. Various
DetNet drafts address many specific aspects of Layer 2 and Layer 3 DetNet drafts address many specific aspects of Layer 2 and Layer 3
integration within a DetNet, and these are not individually integration within a DetNet, and these are not individually
referenced here; security considerations for those aspects are referenced here; security considerations for those aspects are
covered within those drafts or within the related subsections of the covered within those drafts or within the related subsections of the
present document. present document.
Please note that although there are no entries in the L2 and L3 Please note that although there are no entries in the L2 and L3
Integration line of the Mapping Between Themes and Attacks table Integration line of the Mapping Between Themes and Attacks table
Figure 4, this does not imply that there could be no relevant attacks Figure 4, this does not imply that there could be no relevant attacks
related to L2-L3 integration. related to L2-L3 integration.
8.1.6. End-to-End Delivery 8.1.6. End-to-End Delivery
Packets sent over DetNet are not to be dropped by the network due to Packets that are part of a resource-reserved DetNet flow are not to
congestion. (Packets may however intentionally be dropped for be dropped by the DetNet due to congestion. Packets may however be
intended reasons, e.g. per security measures). dropped for intended reasons, for example security measures. For
example, consider the case in which a packet becomes corrupted
(whether incidentally or maliciously) such that the resulting flow ID
incidentally matches the flow ID of another DetNet flow, potentially
resulting in additional unauthorized traffic on the latter. In such
a case it may be a security requirement that the system report and/or
take some defined action, perhaps when a packet drop count threshold
has been reached (see also Section 7.7).
A data plane attack may force packets to be dropped, for example a A data plane attack may force packets to be dropped, for example as a
"long" Delay or Replication/Elimination or Flow Modification attack. result of a Delay attack, Replication/Elimination attack, or Flow
Modification attack.
The same result might be obtained by a controller plane attack, e.g. The same result might be obtained by a controller plane attack, e.g.
Path Manipulation or Signaling Packet Modification. Path Manipulation or Signaling Packet Modification.
It may be that such attacks are limited to Internal on-path
attackers, but other possibilities should be considered.
An attack may also cause packets that should not be delivered to be An attack may also cause packets that should not be delivered to be
delivered, such as by forcing packets from one (e.g. replicated) path delivered, such as by forcing packets from one (e.g. replicated) path
to be preferred over another path when they should not be to be preferred over another path when they should not be
(Replication attack), or by Flow Modification, or by Path Choice or (Replication attack), or by Flow Modification, or by Path Choice or
Packet Injection. A Time Synchronization attack could cause a system Packet Injection. A Time Synchronization attack could cause a system
that was expecting certain packets at certain times to accept that was expecting certain packets at certain times to accept
unintended packets based on compromised system time or time windowing unintended packets based on compromised system time or time windowing
in the scheduler. in the scheduler.
8.1.7. Replacement for Proprietary Fieldbuses and Ethernet-based 8.1.7. Replacement for Proprietary Fieldbuses and Ethernet-based
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8.1.8. Deterministic vs Best-Effort Traffic 8.1.8. Deterministic vs Best-Effort Traffic
Most of the themes described in this document address OT (reserved) Most of the themes described in this document address OT (reserved)
DetNet flows - this item is intended to address issues related to IT DetNet flows - this item is intended to address issues related to IT
traffic on a DetNet. traffic on a DetNet.
DetNet is intended to support coexistence of time-sensitive DetNet is intended to support coexistence of time-sensitive
operational (OT, deterministic) traffic and information (IT, "best operational (OT, deterministic) traffic and information (IT, "best
effort") traffic on the same ("unified") network. effort") traffic on the same ("unified") network.
With DetNet, this coexistance will become more common, and With DetNet, this coexistence will become more common, and
mitigations will need to be established. The fact that the IT mitigations will need to be established. The fact that the IT
traffic on a DetNet is limited to a corporate controlled network traffic on a DetNet is limited to a corporate controlled network
makes this a less difficult problem compared to being exposed to the makes this a less difficult problem compared to being exposed to the
open Internet, however this aspect of DetNet security should not be open Internet, however this aspect of DetNet security should not be
underestimated. underestimated.
An Inter-segment attack can flood the network with IT-type traffic An Inter-segment attack can flood the network with IT-type traffic
with the intent of disrupting handling of IT traffic, and/or the goal with the intent of disrupting handling of IT traffic, and/or the goal
of interfering with OT traffic. Presumably if the DetNet flow of interfering with OT traffic. Presumably if the DetNet flow
reservation and isolation of the DetNet is well-designed (better- reservation and isolation of the DetNet is well-designed (better-
designed than the attack) then interference with OT traffic should designed than the attack) then interference with OT traffic should
not result from an attack that floods the network with IT traffic. not result from an attack that floods the network with IT traffic.
However the handling of IT traffic by the DetNet may not (by design) The handling of IT traffic (i.e. traffic which by definition is not
be as resilient to DOS attack, and thus designers must be otherwise guaranteed any given deterministic service properties) by the DetNet
prepared to mitigate DOS attacks on IT traffic in a DetNet. will by definition not be given the DetNet-specific protections
provided to DetNet (resource-reserved) flows. The implication is
that the IT traffic on the DetNet network will necessarily have its
own specific set of product (component or system) requirements for
protection against attacks such as DOS; presumably they will be less
stringent than those for OT flows, but nonetheless component and
system designers must employ whatever mitigations will meet the
specified security requirements for IT traffic for the given
component or DetNet.
The network design as a whole also needs to consider possible The network design as a whole also needs to consider possible
application-level dependencies of "OT"-type applications on services application-level dependencies of "OT"-type applications on services
provided by the "IT part" of the network; for example, does the OT provided by the "IT part" of the network; for example, does the OT
application depend on IT network services such as DNS or OAM? If application depend on IT network services such as DNS or OAM? If
such dependencies exist, how are malicious packet flows handled? such dependencies exist, how are malicious packet flows handled?
Such considerations are typically outside the scope of DetNet proper, Such considerations are typically outside the scope of DetNet proper,
but nonetheless need to be addressed in the overall DetNet network but nonetheless need to be addressed in the overall DetNet network
design for a given use case. design for a given use case.
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A Flow Modification or Spoofing or Header Manipulation or Control A Flow Modification or Spoofing or Header Manipulation or Control
Packet Modification attack could cause packets from one flow to be Packet Modification attack could cause packets from one flow to be
directed to another flow, thus breaching isolation between the flows. directed to another flow, thus breaching isolation between the flows.
8.1.10. Unused Reserved Bandwidth 8.1.10. Unused Reserved Bandwidth
If bandwidth reservations are made for a DetNet flow but the If bandwidth reservations are made for a DetNet flow but the
associated bandwidth is not used at any point in time, that bandwidth associated bandwidth is not used at any point in time, that bandwidth
is made available on the network for best-effort traffic. However, is made available on the network for best-effort traffic. However,
note that security considerations for best-effort traffic on a DetNet note that security considerations for best-effort traffic on a DetNet
network is out of scope of the present document, provided that such network is out of scope of the present document, provided that any
an attack does not affect performance for DetNet OT traffic. such attacks on best-effort traffic do not affect performance for
DetNet OT traffic.
8.1.11. Interoperability 8.1.11. Interoperability
The DetNet network specifications are intended to enable an ecosystem The DetNet specifications as a whole are intended to enable an
in which multiple vendors can create interoperable products, thus ecosystem in which multiple vendors can create interoperable
promoting component diversity and potentially higher numbers of each products, thus promoting component diversity and potentially higher
component manufactured. numbers of each component manufactured. Toward that end, the
security measures and protocols discussed in this document are
The security mechanisms and protocols that are discussed in this intended to encourage interoperability.
document also require interoperability. It is expected that DETNET
network specifications that define security measures and protocols
will be defined in a way that allows interoperability.
Given that the DetNet specifications are unambiguously written and Given that the DetNet specifications are unambiguously written and
that the implementations are accurate, then this should not in and of that the implementations are accurate, the property of
itself cause a security concern; however, in the real world, it could interoperability should not in and of itself cause security concerns;
be. The network operator can mitigate this through sufficient however, flaws in interoperability between components could result in
interoperability testing. security weaknesses. The network operator as well as system and
component designer can all contribute to reducing such weaknesses
through interoperability testing.
8.1.12. Cost Reductions 8.1.12. Cost Reductions
The DetNet network specifications are intended to enable an ecosystem The DetNet network specifications are intended to enable an ecosystem
in which multiple vendors can create interoperable products, thus in which multiple vendors can create interoperable products, thus
promoting higher numbers of each component manufactured, promoting promoting higher numbers of each component manufactured, promoting
cost reduction and cost competition among vendors. cost reduction and cost competition among vendors.
This envisioned breadth of DetNet-enabled products is in general a This envisioned breadth of DetNet-enabled products is in general a
positive factor, however implementation flaws in any individual positive factor, however implementation flaws in any individual
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8.1.13. Insufficiently Secure Components 8.1.13. Insufficiently Secure Components
The DetNet network specifications are intended to enable an ecosystem The DetNet network specifications are intended to enable an ecosystem
in which multiple vendors can create interoperable products, thus in which multiple vendors can create interoperable products, thus
promoting component diversity and potentially higher numbers of each promoting component diversity and potentially higher numbers of each
component manufactured. However this raises the possibility that a component manufactured. However this raises the possibility that a
vendor might repurpose for DetNet applications a hardware or software vendor might repurpose for DetNet applications a hardware or software
component that was originally designed for operation in an isolated component that was originally designed for operation in an isolated
OT network, and thus may not have been designed to be sufficiently OT network, and thus may not have been designed to be sufficiently
secure, or secure at all. Deployment of such a component on a DetNet secure, or secure at all, against the sorts of attacks described in
network that is intended to be highly secure may present an attack this document. Deployment of such a component on a DetNet network
surface. that is intended to be highly secure may present an attack surface;
thus the DetNet network operator may need to take specific actions to
The DetNet network operator may need to take specific actions to protect such components, for example by implementing a secure
protect such components, such as implementing a dedicated security interface (such as a firewall) to isolate the component from the
layer around the component. threats that may be present in the greater network.
8.1.14. DetNet Network Size 8.1.14. DetNet Network Size
DetNet networks range in size from very small, e.g. inside a single DetNet networks range in size from very small, e.g. inside a single
industrial machine, to very large, for example a Utility Grid network industrial machine, to very large, for example a Utility Grid network
spanning a whole country. spanning a whole country.
The size of the network might be related to how the attack is The size of the network might be related to how the attack is
introduced into the network, for example if the entire network is introduced into the network, for example if the entire network is
local, there is a threat that power can be cut to the entire network. local, there is a threat that power can be cut to the entire network.
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presenting a larger attack surface. Similarly Path Manipulation, presenting a larger attack surface. Similarly Path Manipulation,
Path Choice and Time Synchronization attacks seem more likely Path Choice and Time Synchronization attacks seem more likely
relevant to large networks. relevant to large networks.
8.1.15. Multiple Hops 8.1.15. Multiple Hops
Large DetNet networks (e.g. a Utility Grid network) may involve many Large DetNet networks (e.g. a Utility Grid network) may involve many
"hops" over various kinds of links for example radio repeaters, "hops" over various kinds of links for example radio repeaters,
microwave links, fiber optic links, etc. microwave links, fiber optic links, etc.
An attack that takes advantage of flaws (or even normal operation) in An attacker who has knowledge of the operation of a component or
the device drivers for the various links (through internal knowledge device's internal software (such as "device drivers") may be able to
of how the individual driver or firmware operates) could take take advantage of this knowledge to design an attack that could
proportionately greater advantage of this topology. exploit flaws (or even the specifics of normal operation) in the
communication between the various links.
It is also possible that this DetNet topology will not be in as It is also possible that a large scale DetNet topology containing
common use as other more homogeneous topologies so there may be more various kinds of links may not be in as common use as other more
opportunity for attackers to exploit software and/or protocol flaws homogeneous topologies. This situation may present more opportunity
in the implementations which have not been tested through extensive for attackers to exploit software and/or protocol flaws in or between
use, particularly in the case of early adopters. these components, because these components or configurations may not
have been sufficiently tested for interoperability (in the way they
would be as a result of broad usage). This may be of particular
concern to early adopters of new DetNet components or technologies.
Of the attacks we have defined, the ones identified in Section 8.1.14 Of the attacks we have defined, the ones identified in Section 8.1.14
as germane to large networks are the most relevant. as germane to large networks are the most relevant.
8.1.16. Level of Service 8.1.16. Level of Service
A DetNet is expected to provide means to configure the network that A DetNet is expected to provide means to configure the network that
include querying network path latency, requesting bounded latency for include querying network path latency, requesting bounded latency for
a given DetNet flow, requesting worst case maximum and/or minimum a given DetNet flow, requesting worst case maximum and/or minimum
latency for a given path or DetNet flow, and so on. It is an latency for a given path or DetNet flow, and so on. It is an
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lesser degree defeats the purpose of associating attacks with use lesser degree defeats the purpose of associating attacks with use
cases. It also underscores the difficulty of designing "extremely cases. It also underscores the difficulty of designing "extremely
high reliability" networks. high reliability" networks.
In practice, network designers can adopt a risk-based approach, in In practice, network designers can adopt a risk-based approach, in
which only those attacks are mitigated whose potential cost is higher which only those attacks are mitigated whose potential cost is higher
than the cost of mitigation. than the cost of mitigation.
8.1.22. Redundant Paths 8.1.22. Redundant Paths
DetNet based systems are expected to be implemented with essentially This document expects that each DetNet system will be implemented to
arbitrarily high reliability/availability. A strategy used by DetNet some essentially arbitrary level of reliability and/or availability,
for providing such extraordinarily high levels of reliability is to depending on the use case. A strategy used by DetNet for providing
provide redundant paths that can be seamlessly switched between, all extraordinarily high levels of reliability when justified is to
the while maintaining the required performance of that system. provide redundant paths between which traffic can be seamlessly
switched, all the while maintaining the required performance of that
system.
Replication-related attacks are by definition applicable here. Replication-related attacks are by definition applicable here.
Controller plane attacks can also interfere with the configuration of Controller plane attacks can also interfere with the configuration of
redundant paths. redundant paths.
8.1.23. Security Measures 8.1.23. Security Measures
A DetNet network must be made sufficiently secure against problematic If any of the security mechanisms which protect the DetNet are
component or traffic behavior, whether malicious or incidental, and attacked or subverted, this can result in malfunction of the network.
whether affecting a single component or multiple components. If any Thus the security systems themselves needs to be robust against
of the security mechanisms which protect the DetNet from such attacks.
problems are attacked or subverted, this can result in malfunction of
the network. Thus the design of the security system itself needs to
be robust against attacks.
The general topic of protection of security mechanisms is not unique The general topic of protection of security mechanisms is not unique
to DetNet; it is identical to the case of securing any security to DetNet; it is identical to the case of securing any security
mechanism for any network. This document addresses these concerns mechanism for any network. This document addresses these concerns
only to the extent that they are unique to DetNet. only to the extent that they are unique to DetNet.
8.2. Summary of Attack Types per Use Case Common Theme 8.2. Summary of Attack Types per Use Case Common Theme
The List of Attacks table Figure 4 lists the attacks of Section 5, The List of Attacks table Figure 4 lists the attacks of Section 5,
Security Threats, assigning a number to each type of attack. That Security Threats, assigning a number to each type of attack. That
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+----+-------------------------------------------+ +----+-------------------------------------------+
| 9 |Control or Signaling Packet Injection | | 9 |Control or Signaling Packet Injection |
+----+-------------------------------------------+ +----+-------------------------------------------+
| 10 |Reconnaissance | | 10 |Reconnaissance |
+----+-------------------------------------------+ +----+-------------------------------------------+
| 11 |Attacks on Time Synchronization Mechanisms | | 11 |Attacks on Time Synchronization Mechanisms |
+----+-------------------------------------------+ +----+-------------------------------------------+
Figure 4: List of Attacks Figure 4: List of Attacks
The Mapping Between Themes and Attacks table Figure 5maps the use The Mapping Between Themes and Attacks table Figure 5 maps the use
case themes of [RFC8578] (as also enumerated in this document) to the case themes of [RFC8578] (as also enumerated in this document) to the
attacks of Figure 4. Each row specifies a theme, and the attacks attacks of Figure 4. Each row specifies a theme, and the attacks
relevant to this theme are marked with a '+'. The row items which relevant to this theme are marked with a '+'. The row items which
have no threats associated with them are included in the table for have no threats associated with them are included in the table for
completeness of the list of Use Case Common Themes, and do not have completeness of the list of Use Case Common Themes, and do not have
DetNet-specific threats associated with them. DetNet-specific threats associated with them.
+----------------------------+--------------------------------+ +----------------------------+--------------------------------+
| Theme | Attack | | Theme | Attack |
| +--+--+--+--+--+--+--+--+--+--+--+ | +--+--+--+--+--+--+--+--+--+--+--+
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+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Proprietary Deterministic | | | +| | | +| +| +| +| | | |Proprietary Deterministic | | | +| | | +| +| +| +| | |
|Ethernet Networks | | | | | | | | | | | | |Ethernet Networks | | | | | | | | | | | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Replacement for Proprietary | | | +| | | +| +| +| +| | | |Replacement for Proprietary | | | +| | | +| +| +| +| | |
|Fieldbuses | | | | | | | | | | | | |Fieldbuses | | | | | | | | | | | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Deterministic vs. Best- | | | +| | | | | | | | | |Deterministic vs. Best- | | | +| | | | | | | | |
|Effort Traffic | | | | | | | | | | | | |Effort Traffic | | | | | | | | | | | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Deterministic Flows | | +| +| | +| +| | +| | | | |Deterministic Flows | +| +| +| | +| +| | +| | | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Unused Reserved Bandwidth | | +| +| | | | | +| +| | | |Unused Reserved Bandwidth | | +| +| | | | | +| +| | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Interoperability | | | | | | | | | | | | |Interoperability | | | | | | | | | | | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Cost Reductions | | | | | | | | | | | | |Cost Reductions | | | | | | | | | | | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Insufficiently Secure | | | | | | | | | | | | |Insufficiently Secure | | | | | | | | | | | |
|Components | | | | | | | | | | | | |Components | | | | | | | | | | | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|DetNet Network Size | +| | | | | +| +| | | | +| |DetNet Network Size | +| | | | | +| +| | | | +|
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Multiple Hops | +| +| | | | +| +| | | | +| |Multiple Hops | +| +| | | | +| +| | | | +|
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Level of Service | | | | | | | | +| +| +| | |Level of Service | | | | | | | | +| +| +| |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Bounded Latency | +| | | | | | | | | | +| |Bounded Latency | +| | | | | | | | | | +|
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Low Latency | +| | | | | | | +| +| +| +| |Low Latency | +| | | | | | | +| +| | +|
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Bounded Jitter | +| | | | | | | | | | | |Bounded Jitter | +| | | | | | | | | | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Symmetric Path Delays | +| | | | | | | | | | +| |Symmetric Path Delays | +| | | | | | | | | | +|
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Reliability and Availability| +| +| +| +| +| +| +| +| +| +| +| |Reliability and Availability| +| +| +| +| +| +| +| +| +| +| +|
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Redundant Paths | | | | +| +| | | +| +| | | |Redundant Paths | | | | +| +| | | +| +| | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Security Measures | | | | | | | | | | | | |Security Measures | | | | | | | | | | | |
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However, if the DetNet nodes cannot decrypt IPsec traffic, then However, if the DetNet nodes cannot decrypt IPsec traffic, then
DetNet flow identification for encrypted IP traffic flows must be DetNet flow identification for encrypted IP traffic flows must be
performed in a different way than it would be for unencrypted IP performed in a different way than it would be for unencrypted IP
DetNet flows. The DetNet IP Data Plane identifies unencrypted flows DetNet flows. The DetNet IP Data Plane identifies unencrypted flows
via a 6-tuple that consists of two IP addresses, the transport via a 6-tuple that consists of two IP addresses, the transport
protocol ID, two transport protocol port numbers and the DSCP in the protocol ID, two transport protocol port numbers and the DSCP in the
IP header. When IPsec is used, the transport header is encrypted and IP header. When IPsec is used, the transport header is encrypted and
the next protocol ID is an IPsec protocol, usually ESP, and not a the next protocol ID is an IPsec protocol, usually ESP, and not a
transport protocol, leaving only three components of the 6-tuple, transport protocol, leaving only three components of the 6-tuple,
which are the two IP addresses and the DSCP. Identification of which are the two IP addresses and the DSCP. If the IPsec sessions
DetNet flows over IPsec is further discussed in Section 5.1.2.3. of are established by a controller, then this controller could also
[RFC8939]. transmit (in the clear) the Security Parameter Index (SPI) and thus
the SPI could be used (in addition to the pair of IP addresses) for
flow identification. Identification of DetNet flows over IPsec is
further discussed in Section 5.1.2.3. of [RFC8939].
Sections below discuss threats specific to IP and MPLS in more Sections below discuss threats specific to IP and MPLS in more
detail. detail.
9.1. IP 9.1. IP
The IP protocol has a long history of security considerations and The IP protocol has a long history of security considerations and
architectural protection mechanisms. From a data plane perspective architectural protection mechanisms. From a data plane perspective
DetNet does not add or modify any IP header information, so the DetNet does not add or modify any IP header information, so the
carriage of DetNet traffic over an IP data plane does not introduce carriage of DetNet traffic over an IP data plane does not introduce
skipping to change at page 46, line 8 skipping to change at page 52, line 13
operation of DetNet over some types of MPLS network. operation of DetNet over some types of MPLS network.
[RFC5921] introduces to MPLS new Operations, Administration, and [RFC5921] introduces to MPLS new Operations, Administration, and
Maintenance (OAM) capabilities, a transport-oriented path protection Maintenance (OAM) capabilities, a transport-oriented path protection
mechanism, and strong emphasis on static provisioning supported by mechanism, and strong emphasis on static provisioning supported by
network management systems. network management systems.
The operation of DetNet over an MPLS network is modeled on the The operation of DetNet over an MPLS network is modeled on the
operation of multi-segment pseudowires (MS-PW). Thus for guidance on operation of multi-segment pseudowires (MS-PW). Thus for guidance on
securing the DetNet elements of DetNet over MPLS the reader is securing the DetNet elements of DetNet over MPLS the reader is
referred to the MS-PW security mechanisms as defined in [RFC8077], referred to the security considerations of [RFC8077], [RFC3931],
[RFC3931], [RFC3985], [RFC6073], and [RFC6478]. [RFC3985], [RFC6073], and [RFC6478].
Having attended to the conventional aspects of network security it is Having attended to the conventional aspects of network security it is
necessary to attend to the dynamic aspects. The closest experience necessary to attend to the dynamic aspects. The closest experience
that the IETF has with securing protocols that are sensitive to that the IETF has with securing protocols that are sensitive to
manipulation of delay are the two way time transfer protocols (TWTT), manipulation of delay are the two way time transfer protocols (TWTT),
which are NTP [RFC5905] and Precision Time Protocol [IEEE1588]. The which are NTP [RFC5905] and Precision Time Protocol [IEEE1588]. The
security requirements for these are described in [RFC7384]. security requirements for these are described in [RFC7384].
One particular problem that has been observed in operational tests of One particular problem that has been observed in operational tests of
TWTT protocols is the ability for two closely but not completely TWTT protocols is the ability for two closely but not completely
synchronized flows to beat and cause a sudden phase hit to one of the synchronized flows to beat and cause a sudden phase hit to one of the
flows. This can be mitigated by the careful use of a scheduling flows. This can be mitigated by the careful use of a scheduling
system in the underlying packet transport. system in the underlying packet transport.
Further consideration of protection against dynamic attacks is work Some investigations into protection of MPLS systems against dynamic
in progress. New work on MPLS security may also be applicable, for attacks exist, such as [I-D.ietf-mpls-opportunistic-encrypt]; perhaps
example [I-D.ietf-mpls-opportunistic-encrypt]. deployment of DetNets will encourage additional such investigations.
10. IANA Considerations 10. IANA Considerations
This document includes no requests from IANA. This document includes no requests from IANA.
11. Security Considerations 11. Security Considerations
The security considerations of DetNet networks are presented The security considerations of DetNet networks are presented
throughout this document. throughout this document.
12. Privacy Considerations 12. Privacy Considerations
Privacy in the context of DetNet is maintained by the base Privacy in the context of DetNet is maintained by the base
technologies specific to the DetNet and user traffic. For example technologies specific to the DetNet and user traffic. For example
TSN can use MACsec, IP can use IPsec, applications can use IP TSN can use MACsec, IP can use IPsec, applications can use IP
transport protocol-provided methods e.g. TLS and DTLS. MPLS transport protocol-provided methods e.g. TLS and DTLS. MPLS
typically uses L2/L3 VPNs combined with the previously mentioned typically uses L2/L3 VPNs combined with the previously mentioned
privacy methods. privacy methods.
However, note that reconnaissance threats such as traffic analysis
and monitoring of electrical side channels can still cause there to
be privacy considerations even when traffic is encrypted.
13. Contributors 13. Contributors
The Editor would like to recognize the contributions of the following The Editor would like to recognize the contributions of the following
individuals to this draft. individuals to this draft.
Subir Das (Applied Communication Sciences) Subir Das (Applied Communication Sciences)
150 Mount Airy Road, Basking Ridge, New Jersey, 07920, USA 150 Mount Airy Road, Basking Ridge, New Jersey, 07920, USA
email sdas@appcomsci.com email sdas@appcomsci.com
John Dowdell (Airbus Defence and Space) John Dowdell (Airbus Defence and Space)
skipping to change at page 48, line 13 skipping to change at page 54, line 23
<https://www.rfc-editor.org/info/rfc8939>. <https://www.rfc-editor.org/info/rfc8939>.
14.2. Informative References 14.2. Informative References
[ARINC664P7] [ARINC664P7]
ARINC, "ARINC 664 Aircraft Data Network, Part 7, Avionics ARINC, "ARINC 664 Aircraft Data Network, Part 7, Avionics
Full-Duplex Switched Ethernet Network", 2009. Full-Duplex Switched Ethernet Network", 2009.
[I-D.ietf-detnet-flow-information-model] [I-D.ietf-detnet-flow-information-model]
Varga, B., Farkas, J., Cummings, R., Jiang, Y., and D. Varga, B., Farkas, J., Cummings, R., Jiang, Y., and D.
Fedyk, "DetNet Flow Information Model", draft-ietf-detnet- Fedyk, "DetNet Flow and Service Information Model", draft-
flow-information-model-12 (work in progress), December ietf-detnet-flow-information-model-14 (work in progress),
2020. January 2021.
[I-D.ietf-detnet-ip-oam] [I-D.ietf-detnet-ip-oam]
Mirsky, G., Chen, M., and D. Black, "Operations, Mirsky, G., Chen, M., and D. Black, "Operations,
Administration and Maintenance (OAM) for Deterministic Administration and Maintenance (OAM) for Deterministic
Networks (DetNet) with IP Data Plane", draft-ietf-detnet- Networks (DetNet) with IP Data Plane", draft-ietf-detnet-
ip-oam-00 (work in progress), September 2020. ip-oam-01 (work in progress), January 2021.
[I-D.ietf-detnet-ip-over-mpls] [I-D.ietf-detnet-ip-over-mpls]
Varga, B., Berger, L., Fedyk, D., Bryant, S., and J. Varga, B., Berger, L., Fedyk, D., Bryant, S., and J.
Korhonen, "DetNet Data Plane: IP over MPLS", draft-ietf- Korhonen, "DetNet Data Plane: IP over MPLS", draft-ietf-
detnet-ip-over-mpls-09 (work in progress), October 2020. detnet-ip-over-mpls-09 (work in progress), October 2020.
[I-D.ietf-detnet-ip-over-tsn] [I-D.ietf-detnet-ip-over-tsn]
Varga, B., Farkas, J., Malis, A., and S. Bryant, "DetNet Varga, B., Farkas, J., Malis, A., and S. Bryant, "DetNet
Data Plane: IP over IEEE 802.1 Time Sensitive Networking Data Plane: IP over IEEE 802.1 Time Sensitive Networking
(TSN)", draft-ietf-detnet-ip-over-tsn-04 (work in (TSN)", draft-ietf-detnet-ip-over-tsn-05 (work in
progress), November 2020. progress), December 2020.
[I-D.ietf-detnet-mpls-oam] [I-D.ietf-detnet-mpls-oam]
Mirsky, G. and M. Chen, "Operations, Administration and Mirsky, G. and M. Chen, "Operations, Administration and
Maintenance (OAM) for Deterministic Networks (DetNet) with Maintenance (OAM) for Deterministic Networks (DetNet) with
MPLS Data Plane", draft-ietf-detnet-mpls-oam-01 (work in MPLS Data Plane", draft-ietf-detnet-mpls-oam-02 (work in
progress), July 2020. progress), January 2021.
[I-D.ietf-detnet-mpls-over-udp-ip] [I-D.ietf-detnet-mpls-over-udp-ip]
Varga, B., Farkas, J., Berger, L., Malis, A., and S. Varga, B., Farkas, J., Berger, L., Malis, A., and S.
Bryant, "DetNet Data Plane: MPLS over UDP/IP", draft-ietf- Bryant, "DetNet Data Plane: MPLS over UDP/IP", draft-ietf-
detnet-mpls-over-udp-ip-07 (work in progress), October detnet-mpls-over-udp-ip-08 (work in progress), December
2020. 2020.
[I-D.ietf-detnet-yang]
Geng, X., Chen, M., Ryoo, Y., Fedyk, D., Rahman, R., and
Z. Li, "Deterministic Networking (DetNet) Configuration
YANG Model", draft-ietf-detnet-yang-09 (work in progress),
November 2020.
[I-D.ietf-ipsecme-g-ikev2] [I-D.ietf-ipsecme-g-ikev2]
Smyslov, V. and B. Weis, "Group Key Management using Smyslov, V. and B. Weis, "Group Key Management using
IKEv2", draft-ietf-ipsecme-g-ikev2-01 (work in progress), IKEv2", draft-ietf-ipsecme-g-ikev2-02 (work in progress),
July 2020. January 2021.
[I-D.ietf-mpls-opportunistic-encrypt] [I-D.ietf-mpls-opportunistic-encrypt]
Farrel, A. and S. Farrell, "Opportunistic Security in MPLS Farrel, A. and S. Farrell, "Opportunistic Security in MPLS
Networks", draft-ietf-mpls-opportunistic-encrypt-03 (work Networks", draft-ietf-mpls-opportunistic-encrypt-03 (work
in progress), March 2017. in progress), March 2017.
[I-D.varga-detnet-service-model] [I-D.varga-detnet-service-model]
Varga, B. and J. Farkas, "DetNet Service Model", draft- Varga, B. and J. Farkas, "DetNet Service Model", draft-
varga-detnet-service-model-02 (work in progress), May varga-detnet-service-model-02 (work in progress), May
2017. 2017.
skipping to change at page 50, line 37 skipping to change at page 57, line 5
[RFC3931] Lau, J., Ed., Townsley, M., Ed., and I. Goyret, Ed., [RFC3931] Lau, J., Ed., Townsley, M., Ed., and I. Goyret, Ed.,
"Layer Two Tunneling Protocol - Version 3 (L2TPv3)", "Layer Two Tunneling Protocol - Version 3 (L2TPv3)",
RFC 3931, DOI 10.17487/RFC3931, March 2005, RFC 3931, DOI 10.17487/RFC3931, March 2005,
<https://www.rfc-editor.org/info/rfc3931>. <https://www.rfc-editor.org/info/rfc3931>.
[RFC3985] Bryant, S., Ed. and P. Pate, Ed., "Pseudo Wire Emulation [RFC3985] Bryant, S., Ed. and P. Pate, Ed., "Pseudo Wire Emulation
Edge-to-Edge (PWE3) Architecture", RFC 3985, Edge-to-Edge (PWE3) Architecture", RFC 3985,
DOI 10.17487/RFC3985, March 2005, DOI 10.17487/RFC3985, March 2005,
<https://www.rfc-editor.org/info/rfc3985>. <https://www.rfc-editor.org/info/rfc3985>.
[RFC4107] Bellovin, S. and R. Housley, "Guidelines for Cryptographic
Key Management", BCP 107, RFC 4107, DOI 10.17487/RFC4107,
June 2005, <https://www.rfc-editor.org/info/rfc4107>.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the [RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
December 2005, <https://www.rfc-editor.org/info/rfc4301>. December 2005, <https://www.rfc-editor.org/info/rfc4301>.
[RFC4302] Kent, S., "IP Authentication Header", RFC 4302,
DOI 10.17487/RFC4302, December 2005,
<https://www.rfc-editor.org/info/rfc4302>.
[RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection
(BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010,
<https://www.rfc-editor.org/info/rfc5880>. <https://www.rfc-editor.org/info/rfc5880>.
[RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch,
"Network Time Protocol Version 4: Protocol and Algorithms "Network Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010,
<https://www.rfc-editor.org/info/rfc5905>. <https://www.rfc-editor.org/info/rfc5905>.
[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS [RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS
skipping to change at page 51, line 29 skipping to change at page 58, line 5
[RFC6274] Gont, F., "Security Assessment of the Internet Protocol [RFC6274] Gont, F., "Security Assessment of the Internet Protocol
Version 4", RFC 6274, DOI 10.17487/RFC6274, July 2011, Version 4", RFC 6274, DOI 10.17487/RFC6274, July 2011,
<https://www.rfc-editor.org/info/rfc6274>. <https://www.rfc-editor.org/info/rfc6274>.
[RFC6478] Martini, L., Swallow, G., Heron, G., and M. Bocci, [RFC6478] Martini, L., Swallow, G., Heron, G., and M. Bocci,
"Pseudowire Status for Static Pseudowires", RFC 6478, "Pseudowire Status for Static Pseudowires", RFC 6478,
DOI 10.17487/RFC6478, May 2012, DOI 10.17487/RFC6478, May 2012,
<https://www.rfc-editor.org/info/rfc6478>. <https://www.rfc-editor.org/info/rfc6478>.
[RFC6562] Perkins, C. and JM. Valin, "Guidelines for the Use of
Variable Bit Rate Audio with Secure RTP", RFC 6562,
DOI 10.17487/RFC6562, March 2012,
<https://www.rfc-editor.org/info/rfc6562>.
[RFC6632] Ersue, M., Ed. and B. Claise, "An Overview of the IETF [RFC6632] Ersue, M., Ed. and B. Claise, "An Overview of the IETF
Network Management Standards", RFC 6632, Network Management Standards", RFC 6632,
DOI 10.17487/RFC6632, June 2012, DOI 10.17487/RFC6632, June 2012,
<https://www.rfc-editor.org/info/rfc6632>. <https://www.rfc-editor.org/info/rfc6632>.
[RFC6941] Fang, L., Ed., Niven-Jenkins, B., Ed., Mansfield, S., Ed., [RFC6941] Fang, L., Ed., Niven-Jenkins, B., Ed., Mansfield, S., Ed.,
and R. Graveman, Ed., "MPLS Transport Profile (MPLS-TP) and R. Graveman, Ed., "MPLS Transport Profile (MPLS-TP)
Security Framework", RFC 6941, DOI 10.17487/RFC6941, April Security Framework", RFC 6941, DOI 10.17487/RFC6941, April
2013, <https://www.rfc-editor.org/info/rfc6941>. 2013, <https://www.rfc-editor.org/info/rfc6941>.
[RFC7384] Mizrahi, T., "Security Requirements of Time Protocols in [RFC7384] Mizrahi, T., "Security Requirements of Time Protocols in
Packet Switched Networks", RFC 7384, DOI 10.17487/RFC7384, Packet Switched Networks", RFC 7384, DOI 10.17487/RFC7384,
October 2014, <https://www.rfc-editor.org/info/rfc7384>. October 2014, <https://www.rfc-editor.org/info/rfc7384>.
[RFC7567] Baker, F., Ed. and G. Fairhurst, Ed., "IETF [RFC7567] Baker, F., Ed. and G. Fairhurst, Ed., "IETF
Recommendations Regarding Active Queue Management", Recommendations Regarding Active Queue Management",
BCP 197, RFC 7567, DOI 10.17487/RFC7567, July 2015, BCP 197, RFC 7567, DOI 10.17487/RFC7567, July 2015,
<https://www.rfc-editor.org/info/rfc7567>. <https://www.rfc-editor.org/info/rfc7567>.
[RFC7641] Hartke, K., "Observing Resources in the Constrained
Application Protocol (CoAP)", RFC 7641,
DOI 10.17487/RFC7641, September 2015,
<https://www.rfc-editor.org/info/rfc7641>.
[RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID [RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID
Separation Protocol (LISP) Threat Analysis", RFC 7835, Separation Protocol (LISP) Threat Analysis", RFC 7835,
DOI 10.17487/RFC7835, April 2016, DOI 10.17487/RFC7835, April 2016,
<https://www.rfc-editor.org/info/rfc7835>. <https://www.rfc-editor.org/info/rfc7835>.
[RFC8077] Martini, L., Ed. and G. Heron, Ed., "Pseudowire Setup and [RFC8077] Martini, L., Ed. and G. Heron, Ed., "Pseudowire Setup and
Maintenance Using the Label Distribution Protocol (LDP)", Maintenance Using the Label Distribution Protocol (LDP)",
STD 84, RFC 8077, DOI 10.17487/RFC8077, February 2017, STD 84, RFC 8077, DOI 10.17487/RFC8077, February 2017,
<https://www.rfc-editor.org/info/rfc8077>. <https://www.rfc-editor.org/info/rfc8077>.
skipping to change at page 52, line 44 skipping to change at line 2742
Huawei Network.IO Innovation Lab Huawei Network.IO Innovation Lab
Email: tal.mizrahi.phd@gmail.com Email: tal.mizrahi.phd@gmail.com
Andrew J. Hacker Andrew J. Hacker
MistIQ Technologies, Inc MistIQ Technologies, Inc
Harrisburg, PA Harrisburg, PA
USA USA
Email: ajhacker@mistiqtech.com Email: ajhacker@mistiqtech.com
URI: http://www.mistiqtech.com
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