| draft-ietf-bfd-rfc5884-clarifications-01.txt | draft-ietf-bfd-rfc5884-clarifications-02.txt | |||
|---|---|---|---|---|
| Internet Engineering Task Force V. Govindan | Internet Engineering Task Force V. Govindan | |||
| Internet-Draft Cisco Systems | Internet-Draft K. Rajaraman | |||
| Updates: 5884 (if approved) K. Rajaraman | Updates: 5884 (if approved) Cisco Systems | |||
| Intended status: Standards Track G. Mirsky | Intended status: Standards Track G. Mirsky | |||
| Expires: September 06, 2015 Ericsson | Expires: December 18, 2015 Ericsson | |||
| N. Akiya | N. Akiya | |||
| Big Switch Networks | ||||
| S. Aldrin | S. Aldrin | |||
| Huawei Technologies | ||||
| March 05, 2015 | June 16, 2015 | |||
| Clarifications to RFC 5884 | Clarifications to RFC 5884 | |||
| draft-ietf-bfd-rfc5884-clarifications-01 | draft-ietf-bfd-rfc5884-clarifications-02 | |||
| Abstract | Abstract | |||
| This document clarifies the procedures for establishing, maintaining | This document clarifies the procedures for establishing, maintaining | |||
| and removing multiple, concurrent BFD sessions for a given <MPLS LSP, | and removing multiple, concurrent BFD sessions for a given <MPLS LSP, | |||
| FEC> described in RFC5884. | FEC> described in RFC5884. | |||
| 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 1, line 37 | skipping to change at page 1, line 38 | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at http://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 | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| This Internet-Draft will expire on September 06, 2015. | This Internet-Draft will expire on December 18, 2015. | |||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2015 IETF Trust and the persons identified as the | Copyright (c) 2015 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (http://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 | publication of this document. Please review these documents | |||
| skipping to change at page 2, line 14 | skipping to change at page 2, line 15 | |||
| include Simplified BSD License text as described in Section 4.e of | include Simplified BSD License text as described in Section 4.e of | |||
| the Trust Legal Provisions and are provided without warranty as | the Trust Legal Provisions and are provided without warranty as | |||
| described in the Simplified BSD License. | described in the Simplified BSD License. | |||
| Table of Contents | Table of Contents | |||
| 1. Background . . . . . . . . . . . . . . . . . . . . . . . . . 2 | 1. Background . . . . . . . . . . . . . . . . . . . . . . . . . 2 | |||
| 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 | 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 | |||
| 2. Theory of Operation . . . . . . . . . . . . . . . . . . . . . 3 | 2. Theory of Operation . . . . . . . . . . . . . . . . . . . . . 3 | |||
| 2.1. Procedures for establishment of multiple BFD sessions . . 3 | 2.1. Procedures for establishment of multiple BFD sessions . . 3 | |||
| 2.2. Procedures for maintenance of multiple BFD sessions . . . 3 | 2.2. Procedures for maintenance of multiple BFD sessions . . . 4 | |||
| 2.3. Procedures for removing BFD sessions at the egress LSR . 4 | 2.3. Procedures for removing BFD sessions at the egress LSR . 4 | |||
| 2.4. Changing discriminators for a BFD session . . . . . . . . 4 | 2.4. Changing discriminators for a BFD session . . . . . . . . 4 | |||
| 3. Backwards Compatibility . . . . . . . . . . . . . . . . . . . 4 | 3. Backwards Compatibility . . . . . . . . . . . . . . . . . . . 5 | |||
| 4. Encapsulation . . . . . . . . . . . . . . . . . . . . . . . . 5 | 4. Encapsulation . . . . . . . . . . . . . . . . . . . . . . . . 5 | |||
| 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 | 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 | |||
| 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 | 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 | |||
| 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 | 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 | |||
| 8. Normative References . . . . . . . . . . . . . . . . . . . . 5 | 8. Normative References . . . . . . . . . . . . . . . . . . . . 5 | |||
| Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 | Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 | |||
| 1. Background | 1. Background | |||
| [RFC5884] defines the procedures to bootstrap and maintain BFD | [RFC5884] defines the procedures to bootstrap and maintain BFD | |||
| skipping to change at page 4, line 4 | skipping to change at page 4, line 6 | |||
| the creation of a BFD session due to policy, it MUST drop the MPLS | the creation of a BFD session due to policy, it MUST drop the MPLS | |||
| Echo request message. | Echo request message. | |||
| Ensure the uniqueness of the <MPLS FEC, LSP, Remote | Ensure the uniqueness of the <MPLS FEC, LSP, Remote | |||
| Discriminiator> tuple. | Discriminiator> tuple. | |||
| The remaining procedures of session establishment are as specified | The remaining procedures of session establishment are as specified | |||
| in [RFC5884]. | in [RFC5884]. | |||
| 2.2. Procedures for maintenance of multiple BFD sessions | 2.2. Procedures for maintenance of multiple BFD sessions | |||
| Both the ingress LSR and egress LSR use the YourDiscriminator of the | Both the ingress LSR and egress LSR use the YourDiscriminator of the | |||
| received BFD packet to demultiplex BFD sessions. | received BFD packet to demultiplex BFD sessions. | |||
| 2.3. Procedures for removing BFD sessions at the egress LSR | 2.3. Procedures for removing BFD sessions at the egress LSR | |||
| [RFC5884] does not specify an explicit procedure for deleting BFD | [RFC5884] does not specify an explicit procedure for deleting BFD | |||
| sessions. The procedure for removing a BFD session established by an | sessions. The procedure for removing a BFD session established by an | |||
| out-of-band discriminator exchange using the MPLS LSP ping can | out-of-band discriminator exchange using the MPLS LSP ping can | |||
| improve resource management (like memory etc.) especially in | improve resource management (like memory etc.) especially in | |||
| scenarios involving thousands or more of such sessions. A few | scenarios involving thousands or more of such sessions. A few | |||
| options are possible here: | observations are made here: | |||
| The BFD session MAY be removed in the egress LSR if the BFD | The BFD session MAY be removed in the egress LSR if the BFD | |||
| session transitions from UP to DOWN. This can be done after the | session transitions from UP to DOWN. This can be done after the | |||
| expiry of a configurable timer started after the BFD session state | expiry of a configurable timer started after the BFD session state | |||
| transitions from UP to DOWN at the egress LSR. | transitions from UP to DOWN at the egress LSR. | |||
| The BFD session on the egress LSR MAY be removed by the ingress | The BFD session on the egress LSR MAY be removed by the ingress | |||
| LSR by using the BFD diagnostic code AdminDown(7) as specified in | LSR by using the BFD diagnostic code AdminDown(7) as specified in | |||
| [RFC5880]. When the ingress LSR wants to remove a session without | [RFC5880]. When the ingress LSR wants to remove a session without | |||
| triggering any state change at the egress, it MAY transmit BFD | triggering any state change at the egress, it MAY transmit BFD | |||
| skipping to change at page 4, line 38 | skipping to change at page 4, line 41 | |||
| triggering a change of state. | triggering a change of state. | |||
| The procedures to be followed at the egress LSR when BFD | The procedures to be followed at the egress LSR when BFD | |||
| session(s) remain in the DOWN state for a significant amount of | session(s) remain in the DOWN state for a significant amount of | |||
| time is a local matter. Such procedures are outside the scope of | time is a local matter. Such procedures are outside the scope of | |||
| this document. | this document. | |||
| All BFD sessions established with the FEC MUST be removed | All BFD sessions established with the FEC MUST be removed | |||
| automatically if the FEC is removed. | automatically if the FEC is removed. | |||
| The egress MUST use the discriminators exchanged when the session | ||||
| was brought UP, to indicate any session state change to the | ||||
| ingress. The egress SHOULD reset this to zero after transmitting | ||||
| bfd.detectMult number of packets if the BFD session transitions to | ||||
| DOWN state. | ||||
| 2.4. Changing discriminators for a BFD session | 2.4. Changing discriminators for a BFD session | |||
| The discriminators of a BFD session established over an MPLS LSP | The discriminators of a BFD session established over an MPLS LSP | |||
| cannot be changed when it is in UP state. The BFD session could be | cannot be changed when it is in UP state. The BFD session could be | |||
| removed after a graceful transition to AdminDown state using the BFD | removed after a graceful transition to AdminDown state using the BFD | |||
| diagnostic code AdminDown. A new session could be established with a | diagnostic code AdminDown. A new session could be established with a | |||
| different discriminator. The initiation of the transition from the | different discriminator. The initiation of the transition from the | |||
| Up to Down state can be done either by the ingress LSR or the egress | Up to Down state can be done either by the ingress LSR or the egress | |||
| LSR. | LSR. | |||
| skipping to change at page 6, line 17 | skipping to change at page 6, line 24 | |||
| Switched Paths (LSPs)", RFC 5884, June 2010. | Switched Paths (LSPs)", RFC 5884, June 2010. | |||
| Authors' Addresses | Authors' Addresses | |||
| Vengada Prasad Govindan | Vengada Prasad Govindan | |||
| Cisco Systems | Cisco Systems | |||
| Email: venggovi@cisco.com | Email: venggovi@cisco.com | |||
| Kalyani Rajaraman | Kalyani Rajaraman | |||
| Ericsson | Cisco Systems | |||
| Email: kalyani.rajaraman@ericsson.com | Email: kalyanir@cisco.com | |||
| Gregory Mirsky | Gregory Mirsky | |||
| Ericsson | Ericsson | |||
| Email: gregory.mirsky@ericsson.com | Email: gregory.mirsky@ericsson.com | |||
| Nobo Akiya | Nobo Akiya | |||
| Big Switch Networks | ||||
| Email: nobo.akiya.dev@gmail.com | Email: nobo.akiya.dev@gmail.com | |||
| Sam Aldrin | Sam Aldrin | |||
| Huawei Technologies | ||||
| Email: aldrin.ietf@gmail.com | Email: aldrin.ietf@gmail.com | |||
| End of changes. 16 change blocks. | ||||
| 14 lines changed or deleted | 23 lines changed or added | |||
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