Multicast In
The number of multicast packets that were received by this interface. Multicast packets are those addressed to a specific group of hosts.
Multicast Out
The number of multicast packets that were routed to this interface for transmission, including those that were discarded or not sent. Multicast packets are those addressed to a specific group of hosts.
Broadcast In
The number of broadcast packets that were received by this interface. Broadcast packets are those addressed to all hosts on a network.
Broadcast Out
The number of broadcast packets that were routed to this interface for transmission, including those that were discarded or not sent. Broadcast packets are those addressed to all hosts on a network.
http://www.cisco.com/en/US/products/hw/vpndevc/ps2284/products_administration_guide_chapter09186a00801f1f7b.html
