Browse Prior Art Database

Cisco Hot Standby Router Protocol (HSRP) (RFC2281)

IP.com Disclosure Number: IPCOM000002843D
Original Publication Date: 1998-Mar-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 14 page(s) / 33K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

T. Li: AUTHOR [+4]

Abstract

The memo specifies the Hot Standby Router Protocol (HSRP). The goal of the protocol is to allow hosts to appear to use a single router and to maintain connectivity even if the actual first hop router they are using fails. Multiple routers participate in this protocol and in concert create the illusion of a single virtual router. The protocol insures that one and only one of the routers is forwarding packets on behalf of the virtual router. End hosts forward their packets to the virtual router.

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

Network Working Group T. Li

Request for Comments: 2281 Juniper Networks

Category: Informational B. Cole

Juniper Networks

P. Morton

Cisco Systems

D. Li

Cisco Systems

March 1998

Cisco Hot Standby Router Protocol (HSRP)

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 (1998). All Rights Reserved.

IESG Note

This document reflects an existing deployed protocol. The IETF does

have a working group which is in the process of producing a standards

track protocol to address the same issues.

Abstract

The memo specifies the Hot Standby Router Protocol (HSRP). The goal

of the protocol is to allow hosts to appear to use a single router

and to maintain connectivity even if the actual first hop router they

are using fails. Multiple routers participate in this protocol and

in concert create the illusion of a single virtual router. The

protocol insures that one and only one of the routers is forwarding

packets on behalf of the virtual router. End hosts forward their

packets to the virtual router.

The router forwarding packets is known as the active router. A

standby router is selected to replace the active router should it

fail. The protocol provides a mechanism for determining active and

standby routers, using the IP addresses on the participating routers.

If an active router fails a standby router can take over without a

major interruption in the host's connectivity. This memo also

discusses the ARP, MAC address, and security issues with this

protocol.

TABLE OF CONTENTS

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

2 Conditions of Use ......................................... 3

3 Scope ..................................................... 4

3.1 Terminology ............................................... 4

4 Definitions ............................................... 4

5 Protocol .................................................. 4

5.1 Packet formats ..........................