Cisco Tip: HSRP MAC Address

If you use HSRP in your network, you are probably familiar with the concept of a virtual IP address. But, did you know that HSRP also uses a virtual MAC address? Yes, indeed. Each HSRP group (standby group) has a MAC address in the following format: 00-00-0c-07-ac-xx (xx represents the standby group in hexadecimal).



If you have a standby group of 8, for example, your virtual MAC address would be 00-00-0c-07-ac-08. Likewise, if you have a standby group of 16, your virtual MAC address would be 00-00-0c-07-ac-10.





For more information on HSRP, check out RFC 2281!