Problem and solution when BGP peer cannot be established

The BGP peer establishment on the firewall needs to use port 179 to establish TCP sessions and requires that OPEN messages be properly exchanged. Perform as follows to rectify the issue:

1. Check whether the AS number and IP address among peers are correct by using the display bgp peer command.
2. Check whether the router IDs configured on both BGP peers are conflicting by using the display bgp peer command.
3. If the loopback interface is used, check whether the peer connect-interface command is configured to specify the loopback interface as the source interface for sending BGP packets.
4. If EBGP neighbors are not directly connected to the physical layer, check whether the peer ebgp-max-hop command is configured.
5. Check whether there are available routes to the peer in the routing table.
6. Check whether there are reachable routes to the specified connect-interface by using the ping -a source-ip-address host-address command.
7. Check whether the ACL that is used to disable TCP port 179 is configured.

Scroll to top