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Restart Signaling for Intermediate System to Intermediate System (IS-IS) (RFC3847)

IP.com Disclosure Number: IPCOM000029561D
Original Publication Date: 2004-Jul-01
Included in the Prior Art Database: 2004-Jul-07
Document File: 22 page(s) / 50K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

M. Shand: AUTHOR [+2]

Abstract

This document describes a mechanism for a restarting router to signal to its neighbors that it is restarting, allowing them to reestablish their adjacencies without cycling through the down state, while still correctly initiating database synchronization.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 6% of the total text.

Network Working Group                                           M. Shand

Request for Comments: 3847                                   L. Ginsberg

Category: Informational                                    Cisco Systems

                                                               July 2004

                         Restart Signaling for

          Intermediate System to Intermediate System (IS-IS)

Status of this Memo

   This memo provides information for the Internet community.  It does

   not specify an Internet standard of any kind.  Distribution of this

   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2004).  All Rights Reserved.

Abstract

   This document describes a mechanism for a restarting router to signal

   to its neighbors that it is restarting, allowing them to reestablish

   their adjacencies without cycling through the down state, while still

   correctly initiating database synchronization.

   This document additionally describes a mechanism for a restarting

   router to determine when it has achieved LSP database synchronization

   with its neighbors and a mechanism to optimize LSP database

   synchronization, while minimizing transient routing disruption when a

   router starts.

Shand & Ginsberg             Informational                      [Page 1]

RFC 3847              Restart signaling for IS-IS              July 2004

Table of Contents

   1.  Conventions used in this Document. . . . . . . . . . . . . . .  2

   2.  Overview . . . . . . . . . . . . . . . . . . . . . . . . . . .  3

   3.  Approach . . . . . . . . . . . . . . . . . . . . . . . . . . .  4

       3.1.  Timers . . . . . . . . . . . . . . . . . . . . . . . . .  4

       3.2.  Restart TLV. . . . . . . . . . . . . . . . . . . . . . .  5

             3.2.1.  Use of RR and RA Bits. . . . . . . . . . . . . .  6

             3.2.2.  Use of SA Bit. . . . . . . . . . . . . . . . . .  7

       3.3.  Adjacency (re)Acquisition. . . . . . . . . . . . . . . .  8

             3.3.1.  Adjacency Reacquisition During Restart . . . . .  8

             3.3.2.  Adjacency Acquisition During Start . . . . . . . 10

             3.3.3.  Multiple Levels. . . . . . . . . . . . . . . . . 12

       3.4.  Database Synchronization . . . . . . . . . . . . . . . . 12

             3.4.1.  LSP Generation and Flooding and SPF Computation. 13

                     3.4.1.1. Restarting. . . . . . . . . . . . . . . 13

                     3.4.1.2. Starting. . . . . . . . . . . . . . . . 15

   4.  State Tables . . . . . . ....