A Bit Mask indicating whether the router is forwarding IPv6 multicast datagrams based on the algorithms defined in the Multi- cast 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 mul- ticast 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 Auto- nomous Systems (called inter-AS multicast rout- ing). 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.