HSRP Version Change Implications

C.

HSRP (Hot Standby Router Protocol) is a Cisco proprietary protocol used to provide redundancy for IP networks by allowing two or more routers to work together to present the appearance of a single virtual router to the hosts on a LAN segment.

When the HSRP version is changed from 1 to 2, the behavior that can be expected is that each HSRP group will reinitialize because the virtual MAC address has changed.

The reason for this is that HSRP version 1 uses a virtual MAC address of 0000.0c07.acxx (xx is the HSRP group number in hexadecimal) while HSRP version 2 uses a virtual MAC address of 0000.0c9f.fxxx (xxx is the HSRP group number in hexadecimal). This means that if the HSRP version is changed, the virtual MAC address will also change, and this will cause the routers to reinitialize the HSRP group to advertise the new virtual MAC address to the hosts on the LAN segment.

Option A is not correct because the standby router does not need to be upgraded before the active router. HSRP version 2 is backward compatible with version 1, so both versions can operate in the same network.

Option B is not correct because while version 1 and 2 use the same virtual MAC OUI (Organizationally Unique Identifier), the group numbers in the virtual MAC addresses are different between the two versions.

Option D is not correct because while the multicast address used by HSRP changes between version 1 and 2, this does not cause the HSRP group to reinitialize. The multicast address is used to communicate between the routers in the HSRP group, but it does not affect the virtual MAC address advertised to the hosts on the LAN segment.