For questions about Virtual Router Redundancy Protocol (VRRP), a standards based First Hop Redundancy Protocol (FHRP) defined in RFC 2338.
VRRP 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 IPv4 or IPv6 address(es) associated with a virtual router is called the Master, and it forwards packets sent to these IPv4 or IPv6 addresses. VRRP Master routers are configured with virtual IPv4 or IPv6 addresses, and VRRP Backup routers infer the address family of the virtual addresses being carried based on the transport protocol. Within a VRRP router, the virtual routers in each of the IPv4 and IPv6 address families are a domain unto themselves and do not overlap. The election process provides dynamic failover in the forwarding responsibility should the Master become unavailable.
VRRP provides a function similar to the proprietary protocols "Hot Standby Router Protocol (HSRP)" and "IP Standby Protocol".