--- 1/draft-ietf-manet-dlep-lid-extension-05.txt 2019-09-10 08:13:13.470975809 -0700 +++ 2/draft-ietf-manet-dlep-lid-extension-06.txt 2019-09-10 08:13:13.490976314 -0700 @@ -1,88 +1,88 @@ Mobile Ad hoc Networks Working Group R. Taylor Internet-Draft Airbus Defence & Space Intended status: Standards Track S. Ratliff -Expires: January 26, 2020 VT iDirect - July 25, 2019 +Expires: March 13, 2020 VT iDirect + September 10, 2019 DLEP Link Identifier Extension - draft-ietf-manet-dlep-lid-extension-05 + draft-ietf-manet-dlep-lid-extension-06 Abstract - The Dynamic Link Exchange Protocol (DLEP) [RFC8175] describes a - protocol for modems to advertise the status of wireless links between + The Dynamic Link Exchange Protocol, RFC 8175, describes a protocol + for modems to advertise the status of wireless links between reachable destinations to attached routers. The core specification of the protocol assumes that every modem in the radio network has an attached DLEP router, and requires that the MAC address of the DLEP interface on the attached router be used to identify the destination in the network, for purposes of reporting the state and quality of the link to that destination. This document describes a DLEP Extension allowing modems that do not meet the strict requirement above to use DLEP to describe link availability and quality to one or more destinations reachable beyond a device on the Layer 2 domain. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- - Drafts is at https://datatracker.ietf.org/drafts/current/. + Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on January 26, 2020. + This Internet-Draft will expire on March 13, 2020. Copyright Notice Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents - (https://trustee.ietf.org/license-info) in effect on the date of + (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Applicability . . . . . . . . . . . . . . . . . . . . . . 3 - 1.3. Requirements . . . . . . . . . . . . . . . . . . . . . . 3 + 1.3. Requirements . . . . . . . . . . . . . . . . . . . . . . 4 2. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Identifier Restrictions . . . . . . . . . . . . . . . . . 5 2.2. Negotiation . . . . . . . . . . . . . . . . . . . . . . . 5 3. New Data Items . . . . . . . . . . . . . . . . . . . . . . . 6 3.1. Link Identifier Length Data Item . . . . . . . . . . . . 6 - 3.2. Link Identifier Data Item . . . . . . . . . . . . . . . . 6 + 3.2. Link Identifier Data Item . . . . . . . . . . . . . . . . 7 4. Security Considerations . . . . . . . . . . . . . . . . . . . 7 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 - 6. Normative References . . . . . . . . . . . . . . . . . . . . 7 + 6. Normative References . . . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction - The Dynamic Link Exchange Protocol (DLEP) [RFC8175] describes a + The Dynamic Link Exchange Protocol (DLEP), RFC 8175, describes a protocol for modems to advertise the status of wireless links between reachable destinations to attached routers. The core specification of the protocol assumes that every modem in the radio network has an attached DLEP router, and requires that the MAC address of the DLEP interface on the attached router be used to identify the destination in the network, for purposes of reporting the state and quality of the link to that destination. This document describes a DLEP Extension allowing modems that do not meet the strict requirement above to use DLEP to describe link @@ -152,33 +152,40 @@ Identifier Data Items referring to a new link MUST first appear in a DLEP Destination Up Message from the modem to the router. Once a link has been identified in this way, Link Identifier Data Items may be used by either DLEP participant during the lifetime of a DLEP session. Because of this, a router MUST NOT send a DLEP Destination Announce Message containing a Link Identifier Data Item referring to a link that has not been mentioned in a prior DLEP Destination Up Message. If a modem receives such a message, it MUST terminate the session by issuing a Session Termination Message containing a Status Data Item with status code set to 131 'Invalid Destination' and - transition to the Session Termination state. + transition to the Session Termination state. If a router receives a + Destination Up Message specifying a Link Identifier that has already + been used, the router MUST respond with a Destination Up Response + Message containing a Status Data Item with status code set to 130 + 'Invalid Data', and transition to the Session Termination state. Because the MAC Address associated with any DLEP Destination Message containing a Link Identifier Data Item is not the Layer 2 address of the final destination, all DLEP Destination Up Messages containing a Link Identifier Data Item MUST contain Layer 3 information. In the case of modems that provide Layer 3 wide area network connectivity between devices, this means one or more IPv4 or IPv6 Address Data Items providing the Layer 3 address of the final destination. When referring to some upstream backbone network infrastructure, this means one or more IPv4 or IPv6 Attached Subnet Data Items, for example: '0.0.0.0/0' or '::/0'. This allows the DLEP peer router to - understand the properties of the link to those routes. + understand the properties of the link to those routes. The address + or addresses in the IPv4 or IPv6 Address Data Items MUST be the + addresses in use on the public side of any Network Address + Translation. When the DLEP peer router wishes to route packets to the Layer 3 DLEP Destination, the MAC address associated with the Gateway Node MUST be used as the Layer 2 destination of the packet, if it wishes to use the modem network to forward the packet. As routers populate their routing information base with the IP address of the next hop router towards a destination, implementations supporting this extension SHOULD announce at least one valid IPv4 or IPv6 addresses of the Gateway Node, this removes the need for the @@ -201,25 +208,24 @@ matter and out of scope of this document. Routers must not make any assumptions about the meaning of Link Identifiers, or how Link Identifiers are generated. Within a single DLEP session, all Link Identifiers MUST be unique per MAC Address. This means that a Layer 3 DLEP Destination is uniquely identified by the pair: {MAC Address,Link Identifier}. Link Identifiers MUST NOT be reused, i.e. a {MAC Address,Link Identifier} pair that has been used to refer to one Layer 3 DLEP - Destination MUST NOT be recycled to refer to a different destination - within the lifetime of a single DLEP session. + Destination MUST NOT be used again within the lifetime of a single + DLEP peer-to-peer session. 2.2. Negotiation - To use this extension, as with all DLEP extensions, the extension MUST be announced during DLEP session initialization. A router advertises support by including the value 'Link Identifiers', TBD1 (Section 5), in the Extension Data Item within the Session Initialization Message. A modem advertises support by including the value 'Link Identifiers' in the Extension Data Item within the Session Initialization Response Message. If both DLEP peers advertise support for this extension then Link Identifier Data Items can be included in DLEP Messages. @@ -236,23 +242,27 @@ This extension introduces two new DLEP Data Items: the Link Identifier Data Item (Section 3.2) used to identify a Layer 3 link at or beyond a destination, and the Link Identifier Length Data Item (Section 3.1) used to announce the length of Link Identifiers at session initialization. 3.1. Link Identifier Length Data Item The Link Identifier Length Data Item is used by a DLEP modem implementation to specify the length of Link Identifier Data Items. - It MUST be used during Session Initialization, contained in a Session + If the router advertised support by including the value 'Link + Identifiers' in the Extension Data Item inside the Session + Initialization Message, this data item MAY be used in the Session Initialization Response Message, if the specified length is not the - default value of 4 octets. + default value of 4 octets. If the router did not specify support by + including the value 'Link Identifiers' in the Extension Data item, + this Data Item MUST NOT be sent. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Data Item Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Identifier Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Data Item Type: TBD2 (Section 5) @@ -287,51 +297,51 @@ Destination. This Link Identifier has no implicit meaning and is only used to discriminate between multiple links. 4. Security Considerations As an extension to the core DLEP protocol, the security considerations of that protocol apply to this extension. This extension adds no additional security mechanisms or features. None of the features introduced by this extension require extra - consideration by an implementation. + security consideration by an implementation. 5. IANA Considerations Upon approval of this document, IANA is requested to: - o Assign a new DLEP Extensions Registry value (TBD1) from the + o Assign a new DLEP Extensions Type Registry value (TBD1) from the Specification Required section, named "Link Identifiers". o Assign a new DLEP Data Item Type Values Registry value (TBD2) from the Specification Required section, named "Link Identifier Length". o Assign a new DLEP Data Item Type Values Registry value (TBD3) from the Specification Required section, named "Link Identifier". 6. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate - Requirement Levels", BCP 14, RFC 2119, - DOI 10.17487/RFC2119, March 1997, - . + Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/ + RFC2119, March 1997, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8175] Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and B. Berry, "Dynamic Link Exchange Protocol (DLEP)", RFC 8175, - DOI 10.17487/RFC8175, June 2017, - . + DOI 10.17487/RFC8175, June 2017, . Authors' Addresses Rick Taylor Airbus Defence & Space Quadrant House Celtic Springs Coedkernew Newport NP10 8FZ UK