3Com Switch 8800 Family IPsec Module Configuration and Command reference Guide

15
VRRP CONFIGURATIONS
Introduction to VRRP Virtual router redundancy protocol (VRRP) is a fault-tolerant protocol. Normally,
you can configure a default route for the hosts on a network, for example,
10.100.10.1 in the following figure. All packets destined to the external network
are sent over this default route to Router to gain access to the external networks.
When Router fails, all the hosts using Router as the default next-hop router are
isolated from the external network.
Figure 47 Network diagram for a LAN
VRRP was designed to address this problem on multicast and broadcast LANs such
as Ethernet.
The following figure illustrates how VRRP is implemented.
VRRP combines a group of routers on a LAN (including a master and multiple
backups) into a virtual router called standby group.