A Record of Discussions of Graceful Restart Extensions for Bidirectional Forwarding Detection (BFD)
draft-palanivelan-bfd-v2-gr-13

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INTERNET-DRAFT                                             A.Palanivelan
Intended Status: Historic                                  EMC Corporation
Expires: May 20, 2012                                      Nov 17, 2011

       A Record of Discussions of Graceful Restart Extensions for  
                 Bidirectional Forwarding Detection (BFD) 
                   draft-palanivelan-bfd-v2-gr-13

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A.Palanivelan             Expires May 20, 2012                  [Page 1]
INTERNET DRAFT       draft-palanivelan-bfd-v2-gr-13         May 08, 2011

Abstract

   This document is a historical record of discussions about extending
   the Bidirectional Forwarding Detection (BFD) protocol to provide
   additional capabilities to handle Graceful Restart.

   These discussions took place in the context of the IETF's BFD working
   group, and the consensus in that group was that these extensions
   should not be made.

   This document presents a summary of the challenges to BFD in
   surviving a graceful restart, and outlines a potential protocol
   solution that was discussed and rejected within the BFD working
   group.  The purpose of this document is to provide a record of the
   work done so that future effort will not be wasted.  This document
   does not propose or document any extensions to BFD, and there is no
   intention that it should be implemented in its current form.

Table of Contents

   1  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
   3  Motivations . . . . . . . . . . . . . . . . . . . . . . . . . .  4
     3.1  Restarts with control protocols . . . . . . . . . . . . . .  4
     3.2  BFD Co-existing with Broadband configurations . . . . . . .  5
   4. Extensions to BFD . . . . . . . . . . . . . . . . . . . . . . .  6
     4.1 Diagnostic (Diag)  . . . . . . . . . . . . . . . . . . . . .  6
     4.2 State (Sta)  . . . . . . . . . . . . . . . . . . . . . . . .  7
     4.3 My Restart Interval  . . . . . . . . . . . . . . . . . . . .  7
     4.4 Your Restart Interval  . . . . . . . . . . . . . . . . . . .  7
   5. State Machine for BFD with GR Support . . . . . . . . . . . . .  8
   6. Theory of Operation . . . . . . . . . . . . . . . . . . . . . . 10
     6.1. Session Establishment and GR Timer exchange . . . . . . . . 10
     6.2. Remote Neighbor Restart and Recovery  . . . . . . . . . . . 11
   7  Security Considerations . . . . . . . . . . . . . . . . . . . . 12
   8  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 13
   9 Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . . 13
   10  References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
     10.1  Normative References . . . . . . . . . . . . . . . . . . . 13
     10.2  Informative References . . . . . . . . . . . . . . . . . . 13
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14

 

A.Palanivelan             Expires May 20, 2012                  [Page 2]
INTERNET DRAFT       draft-palanivelan-bfd-v2-gr-13         May 08, 2011

1  Introduction

   The Bidirectional Forwarding Detection protocol [BFD] provides
   mechanism for liveness detection of arbitrary paths between systems.
   It is intended to provide low-overhead, short-duration detection of
   failures in the path between adjacent forwarding engines, including