5-18AnalysisAn MSDP peer relationship between the locally configured connect-interface interface address andthe configured peer address is based on a TCP connection. If the address of local connect-interfaceinterface is inconsistent with the peer address configured on the peer router, no TCP connection can beestablished. If there is no route between the two peers, no TCP connection can be established.Solution1) Check the connectivity of the route between the routers. Use the display ip routing-tablecommand to check that the unicast route between the routers is correct.2) Further check that a unicast route exists between two routers that will become MSDP peers andthat the route leads to the two peers.3) Check that the interface addresses of the MSDP peers are consistent. Use the displaycurrent-configuration command to check that the address of the local connect-interface interfaceis consistent with the address of the corresponding MSDP peer.No SA Entry in the SA Cache of the RouterSymptomAn MSDP fails to send (S, G) forwarding entries through an SA message.AnalysisYou can use the import-source command to send the (S, G) entries of the local multicast domain to theneighboring MSDP peer through SA messages. The acl keyword is optional. If you do not use thiskeyword, all (S, G) entries will be filtered out by default, that is, none of the (S, G) entries in the localmulticast domain will be advertised. Before the import-source command is executed, the system willsend all (S, G) entries in the local multicast domain. If the MSDP fails to send the (S, G) entries of thelocal multicast domain through SA messages, verify that the import-source command is configuredcorrectly.Solution1) Check the connectivity of the route between the routers. Use the display ip routing-tablecommand to check that the unicast route between the routers is correct.2) Further check that a unicast route exists between two routers that will become MSDP peers andthat the route leads to the two peers.3) Verify the configuration of the import-source command and the corresponding ACL to ensure thatthe ACL rule filters the right (S, G) entries.
