An example network device includes a set of interfaces, a control unit, and a forwarding engine. The control unit includes an interface group information repository that stores data defining interface groups. Each interface group includes one or more interfaces. The forwarding engine includes a media access control (MAC) address repository that stores a mapping of a first interface to a source MAC address, and a MAC address management module that determines whether an interface group to which the first interface is assigned is the same interface group as the interface group to which a second interface is assigned. The control unit is configured to receive a layer two (L2) communication via the second interface, wherein the L2 communication includes the source MAC address. The forwarding engine dynamically updates the MAC address repository based on the determination of the MAC address management module.