What is the multicast IPv4 address used by HSRPv2?

The multicast IPv4 address used by HSRPv2 (Hot Standby Router Protocol version 2) is 224.0.0.102. This address is specifically designated for use by HSRPv2 to facilitate communication among routers participating in the HSRP group, allowing them to coordinate their operations as they provide gateway redundancy for clients on a local network.

In HSRPv2, this multicast address enables routers that are configured as standby routers to receive HSRP messages from the active router, ensuring timely failover and continuity of service in the event of a primary router failure. The use of multicast helps optimize traffic since only the routers that are part of the HSRP group will listen to the messages sent to this address.

This allocation of a specific multicast address for HSRPv2 is a deliberate design choice to avoid potential conflicts and ensure that HSRP routers can communicate efficiently without interfering with other multicast traffic on the network.