Virtual Router Redundancy Protocol (VRRP)
RFC 3768
| Document | Type |
RFC - Draft Standard
(April 2004; No errata)
Obsoleted by RFC 5798
Obsoletes RFC 2338
|
|
|---|---|---|---|
| Author | Bob Hinden | ||
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 3768 (Draft Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Alex Zinin | ||
| IESG note |
Implementation report available at http://www.ietf.org/IESG/Implementations/rfc-2338-implementation.txt |
||
| Send notices to | (None) | ||
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. . . . . . . . . . . . . . . . . 18
7.2. Transmitting Packets. . . . . . . . . . . . . . . . . . 19
7.3. Virtual MAC Address . . . . . . . . . . . . . . . . . . 19
8. Operational Issues. . . . . . . . . . . . . . . . . . . . . . 20
8.1. ICMP Redirects. . . . . . . . . . . . . . . . . . . . . 20
8.2. Host ARP Requests . . . . . . . . . . . . . . . . . . . 20
8.3. Proxy ARP . . . . . . . . . . . . . . . . . . . . . . . 20
8.4. Potential Forwarding Loop . . . . . . . . . . . . . . . 21
9. Operation over FDDI, Token Ring, and ATM LANE . . . . . . . . 21
9.1. Operation over FDDI . . . . . . . . . . . . . . . . . . 21
9.2. Operation over Token Ring . . . . . . . . . . . . . . . 21
9.3. Operation over ATM LANE . . . . . . . . . . . . . . . . 23
10. Security Considerations . . . . . . . . . . . . . . . . . . . 23
11. Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . 24
12. References. . . . . . . . . . . . . . . . . . . . . . . . . . 24
12.1. Normative References. . . . . . . . . . . . . . . . . . 24
12.2. Informative References. . . . . . . . . . . . . . . . . 25
13. Changes from RFC2338. . . . . . . . . . . . . . . . . . . . . 25
14. Editor's Address. . . . . . . . . . . . . . . . . . . . . . . 26
15. Full Copyright Statement. . . . . . . . . . . . . . . . . . . 27
1. Introduction
There are a number of methods that an end-host can use to determine
its first hop router towards a particular IP destination. These
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