5-4. Hot Standby Router Protocol for IPv6

Hot Standby Router Protocol (HSRP) provides failover for multiple routers on a common network segment.

• HSRP enables a group of routers to serve as a primary or standby router for hosts on a segment by letting the active HSRP router respond to requests whereas others monitor for failure of the active router.

• HSRP provides a virtual MAC address used by the active router running the protocol.

• Devices running HSRP send and receive multicast UDP-based hello packets to detect router failure and to designate active and standby routers.

• HSRP uses multicast packets to choose and maintain the active HSRP router based on configuration parameters.

• HSRP uses the virtual MAC address of 0000.0c07.acXX, where XX is the hexadecimal value of the group number.