Which protocol uses the virtual MAC address format of 0000.5e00.01XX?

The correct choice is based on the definition of virtual MAC addresses used by various redundancy protocols. The format of 0000.5e00.01XX is specifically designated for the Virtual Router Redundancy Protocol (VRRP).

In VRRP, this virtual MAC address format is utilized to allow multiple routers to share a single virtual IP address. The last two hexadecimal digits (represented by "XX") identify the specific VRRP group. For instance, if the last two digits are "01," it would represent VRRP group 1. This helps client devices in a network to consistently route their packets to the active router within the VRRP configured group without needing to keep track of the individual physical MAC addresses.

Other protocols like HSRPv1, HSRPv2, and GLBP have their own unique virtual MAC addressing schemes. For example, HSRP uses the format 0000.0C07.ACXX, and GLBP employs a different virtual MAC addressing format, which makes them distinguishable from VRRP. Understanding these distinctions is essential for correctly identifying and implementing redundancy protocols in networking environments.