Virtual Router Redundancy Protocol (VRRP)
Backup: A router configured in a VR as a Backup to the Owner configured
for the same VR. There must be a minimum of one Backup in a VR to
support VRRP operation if the Owner fails. Every backup is created with
a configurable priority (default: 100) that determines the precedence for
becoming the Master of the VR if the Owner or another Backup operating
as the Master becomes unavailable.
Master: The Owner or Backup router that is currently the physical forward
ing agent for routed traffic using the VR as a gateway. There can be only
one router operating as the Master for a network or (in the case of a
multinetted VLAN) a subnet. If the router configured as the Owner for a
VR is available to the network, it will also be the Master. If the Owner fails
or loses availability to the network, the highest-priority Backup becomes
Owner: The router configured in a VR to "own" the "virtual" IP address
associated with the VR.(The virtual IP address for the VR must be config
ured as a real IP address on the VLAN on which the VR is configured. The
Owner is automatically configured with the highest VRRP router priority
in the VR (255) and operates as the Master router for the VR unless it
becomes unavailable to the network.
VR (Virtual Router): Consists of one Owner router and one or more
Backup routers, all of which belong to the same network or (in the case
of a multinetted VLAN, the same subnet). The Owner is the router that
owns the IP address(es) associated with the VR. The VR has one virtual
IP address (or, in the case of a multinetted VLAN, multiple, virtual IP
addresses) that corresponds to a real IP address on the Owner, and is
assigned an identification number termed the VRID.
VRID: The identifier for a specific VR configured on a specific VLAN inter-
face. On a given router, a VRID can be used for only one VR in a given
VLAN, but can be used again for a different VR in a different VLAN.