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Virtual Router Redundancy Protocol (VRRP) (RFC3768)

IP.com Disclosure Number: IPCOM000027941D
Original Publication Date: 2004-Apr-01
Included in the Prior Art Database: 2004-Apr-14
Document File: 28 page(s) / 60K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

R. Hinden: AUTHOR [+2]

Abstract

This memo defines the Virtual Router Redundancy Protocol (VRRP). VRRP specifies an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. The VRRP router controlling the IP address(es) associated with a virtual router is called the Master, and forwards packets sent to these IP addresses. The election process provides dynamic fail over in the forwarding responsibility should the Master become unavailable. This allows any of the virtual router IP addresses on the LAN to be used as the default first hop router by end-hosts. The advantage gained from using VRRP is a higher availability default path without requiring configuration of dynamic routing or router discovery protocols on every end-host.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 8% of the total text.

Network Working Group R. Hinden, Ed.

Request for Comments: 3768 Nokia

Obsoletes: 2338 April 2004

Category: Standards Track

Virtual Router Redundancy Protocol (VRRP)

Status of this Memo

This document specifies an Internet standards track protocol for the

Internet community, and requests discussion and suggestions for

improvements. Please refer to the current edition of the "Internet

Official Protocol Standards" (STD 1) for the standardization state

and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

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

Abstract

This memo defines the Virtual Router Redundancy Protocol (VRRP).

VRRP specifies an election protocol that dynamically assigns

responsibility for a virtual router to one of the VRRP routers on a

LAN. The VRRP router controlling the IP address(es) associated with

a virtual router is called the Master, and forwards packets sent to

these IP addresses. The election process provides dynamic fail over

in the forwarding responsibility should the Master become

unavailable. This allows any of the virtual router IP addresses on

the LAN to be used as the default first hop router by end-hosts. The

advantage gained from using VRRP is a higher availability default

path without requiring configuration of dynamic routing or router

discovery protocols on every end-host.

Table of Contents

1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 2

1.1. Contributors. . . . . . . . . . . . . . . . . . . . . . 3

1.2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.3. Definitions . . . . . . . . . . . . . . . . . . . . . . 4

2. Required Features . . . . . . . . . . . . . . . . . . . . . . 5

2.1. IP Address Backup . . . . . . . . . . . . . . . . . . . 5

2.2. Preferred Path Indication . . . . . . . . . . . . . . . 5

2.3. Minimization of Unnecessary Service Disruptions . . . . 5

2.4. Efficient Operation over Extended LANs. . . . . . . . . 6

3. VRRP Overview . . . . . . . . . . . . . . . . . . . . . . . . 6

4. Sample Configurations . . . . . . . . . . . . . . . . . . . . 7

Hinden Standards Track [Page 1]

RFC 3768 VRRP April 2004

4.1. Sample Configuration 1. . . . . . . . . . . . . . . . . 7

4.2. Sample Configuration 2. . . . . . . . . . . . . . . . . 9

5. Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . 10

5.1. VRRP Packet Format. . . . . . . . . . . . . . . . . . . 10

5.2. IP Field Descriptions . . . . . . . . . . . . . . . . . 10

5.3. VRRP Field Descriptions . . . . . . . . . . . . . . . . 11

6. Protocol State Machine. . . . . . . . . . . . . . . . . . . . 13

6.1. Parameters per Virtual Router . . . . . . . . . . . . . 13

6.2. Timers. . . . . . . . . . . . . . . . . . . . . . . . . 14

6.3. State Transition Diagram. . . . . . . . . . . . . . . . 15

6.4. State Descriptions. . . . . . . . . . . . . . . . . . . 15

7. Sending and Receiving VRRP Packets. . . . . . . . . . . . . . 18

7.1. Receiving VRRP Packets. . . . . . . . . . . . . . . . ....