3Com 10014299 manual Vrrp Overview, Displaying and Debugging Vrrp, Vrrp Configuration Examples

46 CONFIGURING VRRP

	This chapter covers the following topics:
	■	VRRP Overview
	■	Configuring VRRP
	■ Displaying and Debugging VRRP
	■	VRRP Configuration Examples
	■	Troubleshooting VRRP
VRRP Overview	Virtual Router Redundancy Protocol (VRRP) is a fault-tolerant protocol. In general,
	a default route (the next hop is 10.100.10.1) is configured for a network host so
	that packets sent by the host with destination addresses not in the local network

segment go through the default route to Router 1 to implement communication between the host and the external network. When Router 1 breaks down, in this network segment all the hosts that regard Router 1 as the default route next-hop stop the communication with the external network.

Figure 207 LAN networking scheme

Router

Network

10.10.100.1

Ethernet

PC PC PC

To solve this problem, VRRP is designed for LANs with multi-casting and broadcasting capabilities, such as Ethernet. VRRP combines a group of LAN routers including a MASTER router and several BACKUP routers into a virtual router, called a standby group.