VRRP
The Virtual Router
Redundancy Protocol specifies an election protocol that dynamically assigns responsibility
for a virtual router to one of the VRRP routers on a LAN. The VRRP router controlling the IP
address(es) associated with a virtual router is called the master router, and forwards
packets sent to these IP addresses. The election process provides dynamic failover in the
forwarding responsibility should the master router become unavailable. In case the master
router fails, the virtual IP address is mapped to a backup router's IP address; this backup
becomes the master router. This allows any of the virtual router IP addresses on the LAN to
be used as the default first-hop router by end-hosts. The advantage gained from using VRRP
is a higher availability default path without requiring configuration of dynamic routing or
router discovery protocols on every host. VRRP is defined in RFC 2338.