Cisco Hot Standby Router Protocol Group Number

1.3.6.1.4.1.9.9.106.1.2.1.1.1

This object along with the ifIndex of a particular interface uniquely identifies an HSRP group. Group numbers 0,1 and 2 are the only valid group numbers for TokenRing interfaces. For other media types, numbers range from 0 to 255. Each interface has its own set of group numbers. There's no relationship between the groups configured on different interfaces. Using a group number on one interface doesn't preclude using the same group number on a different interface. For example, there can be a group 1 on an Ethernet and a group 1 on Token Ring. More details can be found from RFC 2281.