MOSPF is another dense-mode intradomain multicast routing protocol used in some scientific research networks, including the MBONE. One of the first testbed implementations was MOSPF for Proteon Routers by John Moy.
MOSPF introduces a new link-state advertisement (LSA)?the group-membership LSA, which is flooded through the entire area?and identifies MOSPF-enabled routers via a special flag in their router LSAs. MOSPF does not deviate from regular OSPF in its fundamental operation, though. Therefore, you can easily integrate it in a stepwise manner into existing OSPF networks. MOSPF routers avoid nonmulticast-aware OSPF neighbors in their shortest-path first (SPF) calculation. Interoperability with MBONE DVMRP routers is carried out via border gateway routers running both protocols.
Cisco decided not to implement MOSPF because of inherent scalability problems and a clear commitment to PIM. With the router configuration command ignore lsa mospf, syslog messages regarding unsupported LSA type 6 can be suppressed.