What command is used to configure HSRP version 2 on an interface?

The command used to configure Hot Standby Router Protocol (HSRP) version 2 on an interface is "standby version 2." This command enables HSRP version 2, which introduces enhancements over version 1, such as support for a larger number of groups and the capability to use MAC addresses from the nondefault range for HSRP.

Version 2 also allows for the use of IPv6 addresses and is designed to work more efficiently with various routing protocols. This command must be entered in the interface configuration mode for the interface that will participate in the HSRP group.

Commands that mention version 1 or show variations like "standby group version 2" or "standby version-group 2" either don't conform to the correct syntax or reference HSRP features that are not applicable in the same way as "standby version 2." Thus, the specific phrase "standby version 2" is the clear and accurate command for configuring HSRP version 2 on an interface.