Clarifying Procedures for Establishing BFD Sessions for MPLS Label Switched Paths (LSPs)
RFC 7726
Document | Type |
RFC - Proposed Standard
(January 2016; No errata)
Updates RFC 5884
|
|
---|---|---|---|
Authors | Vengada Govindan , Kalyani Rajaraman , Greg Mirsky , Nobo Akiya , Sam Aldrin | ||
Last updated | 2016-01-29 | ||
Replaces | draft-grmas-bfd-rfc5884-clarifications | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Jeffrey Haas | ||
Shepherd write-up | Show (last changed 2015-09-01) | ||
IESG | IESG state | RFC 7726 (Proposed Standard) | |
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Alvaro Retana | ||
Send notices to | aretana@cisco.com | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) V. Govindan Request for Comments: 7726 K. Rajaraman Updates: 5884 Cisco Systems Category: Standards Track G. Mirsky ISSN: 2070-1721 Ericsson N. Akiya Big Switch Networks S. Aldrin Google January 2016 Clarifying Procedures for Establishing BFD Sessions for MPLS Label Switched Paths (LSPs) Abstract This document clarifies the procedures for establishing, maintaining, and removing multiple, concurrent BFD (Bidirectional Forwarding Detection) sessions for a given <MPLS LSP, FEC> as described in RFC 5884. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7726. Govindan, et al. Standards Track [Page 1] RFC 7726 Clarifications to RFC 5884 January 2016 Copyright Notice Copyright (c) 2016 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 (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. Background . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 2. Theory of Operation . . . . . . . . . . . . . . . . . . . . . 3 2.1. Procedures for Establishment 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 2.4. Changing Discriminators for a BFD Session . . . . . . . . 5 3. Backwards Compatibility . . . . . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . 5 5. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 5.1. Normative References . . . . . . . . . . . . . . . . . . 6 5.2. Informative References . . . . . . . . . . . . . . . . . 6 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 1. Background [RFC5884] defines the procedures to bootstrap and maintain BFD sessions for an <MPLS LSP, FEC> using a Label Switched Path (LSP) ping. While Section 4 of [RFC5884] specifies that multiple BFD sessions can be established for an <MPLS LSP, FEC> tuple, the procedures to bootstrap and maintain multiple BFD sessions concurrently over an <MPLS LSP, FEC> are not clearly specified. Additionally, the procedures of removing BFD sessions bootstrapped on the egress Label Switching Router (LSR) are unclear. This document provides those clarifications without deviating from the principles outlined in [RFC5884]. Govindan, et al. Standards Track [Page 2] RFC 7726 Clarifications to RFC 5884 January 2016 The ability for an ingress LSR to establish multiple BFD sessions for an <MPLS LSP, FEC> tuple is useful in scenarios such as LSPs based on Segment Routing [SEG-ROUTING] or LSPs having Equal-Cost Multipath (ECMP). The process used by the ingress LSR to determine the number of BFD session(s) to be bootstrapped for an <MPLS LSP, FEC> tuple and the mechanism used to construct those session(s) are outside the scope of this document. 1.1. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", andShow full document text