A Bit Mask indicating whether the router is forwarding IPv6 multicast datagrams based on the algorithms defined in the Multicast Extensions to OSPF. If intraAreaMulticast set, indicates that the router can forward IPv6 multicast datagrams in the router's directly attached areas (called intra-area multicast routing). If interAreaMulticast set, indicates that the router can forward IPv6 multicast datagrams between OSPFv3 areas (called inter-area multicast routing). If interAsMulticast set, indicates that the router can forward IPv6 multicast datagrams between Autonomous Systems (called inter-AS multicast routing). Only certain combinations of bit settings are allowed, namely: - All bits cleared (no multicasting) - intraAreaMulticast only, - intraAreaMulticast and interAreaMulticast, - intraAreaMulticast and interAsMulticast - intraAreaMulticast, interAreaMulticast and interAsMulticast By default, all bits are cleared.