Like HSRP, Virtual Router Redundancy Protocol (VRRP) allows a group of routers to
form a single virtual router. In an HSRP or VRRP group, one router is elected to handle
all requests sent to the virtual IP address. With HSRP, this is the active router. An HSRP
group has one active router, at least one standby router, and many listening routers. A
VRRP group has one master router and one or more backup routers and is the open standard
implementation of HSRP.