Addressing

Addressing
Up to four virtual MAC addresses are possible per GLBP group. The non-AVG routers are
assigned MAC addresses in sequence by the AVG. A non-AVG router is referred to as an active
virtual forwarder (AVF).
AVF routers fall into two categories. Any one assigned a virtual MAC address by the AVG
directly is known as a primary virtual forwarder. Group members arriving late do not know the
real IP address of the AVG and use hellos to discover its identity. They are then allocated MAC
addresses and are known as secondary virtual forwarders.