An HSRP group is a redundancy group of routers that use a proprietary protocol from Cisco called Hot Standby Routing Protocol. The group provides router backup in the event of a router system failure or an interface failure.
In an HSRP group, several routers that are connected to the same segment of an Ethernet, FDDI, or token-ring network work together to present the appearance of a single virtual router on the LAN. Because the routers share the same IP and MAC addresses, the hosts on the LAN are able to continue forwarding packets to a consistent IP and MAC address in the event of a router failure. The process of transferring the routing responsibilities from one router to another is transparent to the user.
The IP Manager User Guide provides information about creating HSRP groups.