3Com DUA1750-2BAA01 Chapter 41 VRRP Configuration

3Com Switch 8800 Configuration Guide Chapter 41 VRRP Configuration
41-1
Chapter 41 VRRP Configuration
41.1 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.
Ethernet
Switch
Host 1Host 2Host 3
10.100.10.7 10.100.10.8 10.100.10.9
10.100.10.1
Network
Figure 41-1 Network diagram for LAN
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.