An entry in the igmpCondFilterMcastTable containing
information on a particular IP multicast group on a
particular interface. An entry is created by the agent
when it receives on the interface either an IP multicast
datagram destined to the multicast group, or an IGMP
Membership Report for the group. An entry can also be
created by network management to indicate that datagrams
for the multicast group are to be forwarded to the
interface irrespective of the receipt/non-receipt of IGMP
Membership Reports.