Which version of HSRP supports up to 4096 groups?

HSRPv2, or Hot Standby Router Protocol version 2, extends the capabilities introduced in HSRPv1. One of the key enhancements of HSRPv2 is its support for a significantly larger number of groups—up to 4096. This is particularly beneficial in larger network environments where multiple virtual routers are necessary to manage load balancing and redundancy effectively without exhausting available group identifiers.

In addition to the increase in the number of supported groups, HSRPv2 also incorporates other improvements over its predecessor, such as improved authentication options and support for IPv6. This extension is crucial for modern networks that may require a higher number of HSRP configurations to cater to complex routing requirements.

Comparatively, HSRPv1 is limited to a maximum of 255 groups, making it unsuitable for larger or more demanding network architectures. The options referring to HSRPv3 and HSRP Legacy do not correspond to official versions recognized by Cisco. Thus, HSRPv2 stands out as the correct answer due to its capacity for scalability and enhanced features.