Mac Addresses used are as specified in RFC 2281. For
ethernet and fddi interfaces, a MAC address will be in the
range 00:00:0c:07:ac:00 through 00:00:0c:07:ac:ff. The last
octet is the hexadecimal equivalent of cHsrpGrpNumber
(0-255).
Some Ethernet and FDDI interfaces allow a unicast MAC
address for each HSRP group. Certain Ethernet
chipsets(LANCE Ethernet, VGANYLAN and QUICC Ethernet) only
support a single Unicast Mac Address. In this case, only
one HSRP group is allowed.
For TokenRing interfaces, the following three MAC
addresses are permitted (functional addresses):
C0:00:00:01:00:00
C0:00:00:02:00:00
C0:00:00:04:00:00.