Vrid

VRID stands for Virtual Router Identifier, a parameter used by the Virtual Router Redundancy Protocol (VRRP) to distinguish between multiple virtual routers on the same local network segment. In VRRP, a group of routers can provide redundancy for a single virtual default gateway. Each VRRP group is identified by a VRID, and is associated with a single virtual IP address (VIP) that serves as the gateway for hosts on the subnet. All routers configured for the same VRID share the VIP, but only one router acts as the master at any given time.

Operation within a VRID group involves the master router handling traffic to and from the VIP. Backup routers monitor the master via VRRP advertisements exchanged at regular intervals. The master is chosen based on a priority value; higher priority can preempt a lower-priority master, depending on the configuration. This redundancy mechanism allows automatic failover if the current master becomes unavailable, restoring gateway availability without manual intervention.

VRID is scoped per VLAN or subnet; a device can run multiple VRID groups to provide several independent VIPs for different networks. The VRID itself is typically an 8-bit value, commonly in the range of 1–255, with 0 often reserved or unused depending on vendor implementation. While the concept and behavior are standardized, specific values and features may vary by vendor and VRRP version (VRRPv2 and VRRPv3).

VRID is a core concept in VRRP-enabled high-availability networking. See also VRRP and high-availability networking.