VRRP operation
VRRP supports router redundancy through a prioritized election process among routers configured as members of the same virtual router (VR).
A virtual IP address that is also configured as a real IP address on one of the routers
A virtual router MAC address
Using more than one Backup provides additional redundancy. If the Owner and the highest-priority Backup fail, another lower-priority Backup can take over as Master.
The image shown here depicts a basic VLAN topology. In this example, Routers 1, 2 and 3 form a VRRP group. The IP address of the group is the same address configured for the SVI interface of R1 (10.10.100.1).
As the master, R1 owns the virtual IP address of the VRRP group and forwards packets sent to this IP address.
Clients 1 through 3 are configured with the default gateway IP address of 10.10.100.1.
Routers R2 and R3 function as backups. If the master fails, the backup router with highest priority becomes the master and takes over the virtual IP address to provide uninterrupted service for the clients connected to L2 Switch. When Router R1 recovers, it becomes master again.