Introduction To Vrrp - 3Com 8807 Configuration Manual

VRRP C
ONFIGURATION
53

Introduction to VRRP

Virtual Router Redundancy Protocol (VRRP) is a fault-tolerant protocol. In general,
a default route (for example, 10.100.10.1 as shown in the following
internetworking diagram) will be configured for every host on a network, so that
the packets destined to some other network segment from the host will go
through the default route to the Layer 3 Switch, implementing communication
between the host and the external network. If Switch is down, all the hosts on this
segment taking Switch as the next-hop on the default route will be disconnected
from the external network.
Figure 156 Network diagram for LAN
Network
Switch
10.100.10.1
Ethernet
10.100.10.7 10.100.10.8 10.100.10.9
Host 1 Host 2 Host 3
VRRP, designed for LANs with multicast and broadcast capabilities (such as
Ethernet) settles the above problem. The diagram below is taken as an example to
explain the implementation principal of VRRP. VRRP combines a group of LAN
switches (including a Master and several Backups) into a virtual router.