An MSDP Peer Stays in Down State

After an MSDP peer is configured, it stays in Down state.

An MSDP peer relationship is set up based on a TCP connection between a local interface address and a remote MSDP peer.

If the local interface address is different from the MSDP peer address configured on a remote device, the TCP connection cannot be set up.
If two MSDP peers have no route to each other, the TCP connection cannot be set up.

Check whether the two MSDP peers have learned ARP entries from each other.
Run the display arp all command to check ARP entries on the two devices.
Check whether the two devices have reachable unicast routes to each other.
Run the display ip routing-table command to check the routing table of the two devices.
Check whether the interface addresses used to set up MSDP peer relationships are correct.
Run the display current-configuration command to check whether the local interface address is the same as the remote MSDP peer address configured on the remote device.