Reliability; Vrrp Overview - 3Com 7700 Configuration Manual

10

VRRP Overview

R
ELIABILITY
This chapter covers the following topics:
VRRP Overview
■
Configuring VRRP
■
Virtual Router Redundancy Protocol (VRRP) is a fault-tolerant protocol. In general,
a default route, for example, 10.100.10.1 in Figure 1, is configured for every host
on a network, so that packets destined for another network segment go through
the default route to the Layer 3 Switch1, implementing communication between
the host and the external network. If Switch1 is down, all the hosts on this
segment taking Switch1 as the next-hop on the default route are disconnected
from the external network.
Figure 1 LAN Networking
Switch
10.100.10.1
10.100.10.7
Host 1
VRRP, which is designed for LANs with multicast and broadcast capabilities (such
as Ethernet) settles this problem. Figure 2 illustrates the implementation principal
of VRRP. VRRP combines a group of LAN switches, including a master and several
backups, into a virtual router, or backup group.
Internet
Ethernet
10.100.10.8
Host 2
10.100.10.9
Host 3