CANOGA PERKINS 9175 Configuration Guide - Manual (Page 124)

CanogaOS Configuration Guide
20-1
20 Configuring VRRP
20.1 Overview
This chapter provides an overview of Virtual Router Redundancy Protocol (VRRP) and
its implementation.
VRRP eliminates the risk of a single point of failure inherent in a static default routing
environment. It specifies an election protocol that dynamically assigns responsibility for a
virtual router to one of the VRRP routers on a LAN. One of the major advantages of
VRRP is that it makes default path available without requiring configuration of dynamic
routing on every end-host.
20.2 References
The VRRP module is based on :
RFC 3768 (VRRP): Knight, S., et.al "Virtual Router Redundancy Protocol (VRRP)".
20.3 Terminology
Backup Router
VRRP router that backd up an IP address. It assumes forwarding responsibility for the
virtual IP address if the Master fails.
Critical IP
The IP address that the VRRP router send/receive messages on for a particular session.
IP Address Owner
The VRRP Router that has the virtual router's IP address(es) as real interface
address(es). This is the router that, when up, will respond to packets addressed to one of
these IP addresses for ICMP pings, TCP connections, etc.
Master Router
The VRRP router that owns the IP address (i.e., is being backed up), and which is the
default router for forwarding for that IP address.
Virtual IP
The IP address back up by a VRRP session.
Virtual Router
A router managed by VRRP that acts as a default router for hosts on a shared LAN. It
consists of a Virtual Router Identifier and a set of associated IP addresses across a
common LAN. A VRRP Router might backup one or more virtual routers.
VRRP Router
A router runs the Virtual Router Redundancy Protocol. It might participate in one or more
virtual routers.