The list of interfaces on which the group entry is learnt. Each bit in this object represent interfaces denoted by the object fsVcHlPortId associated to the instance identifier denoted by fsSnoopVlanMcastGroupInstanceId. This object alone should be referred in environments where the number of interfaces in the system is scaled to a large value, as the object fsSnoopVlanMcastGroupPortList may not be sufficient to report the full set of interfaces in each switch instance.