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Troubleshooting BGP
BGP peer relationship not established
Symptom
Display BGP peer information by using the
display bgp peer
command. The state of the connection to a
peer cannot become established.
Analysis
To become BGP peers, any two routers must establish a TCP session using port 179 and exchange Open
messages successfully.
Solution
1.
Use the
display current-configuration
command to verify that the peer's AS number is correct.
2.
Use the
display bgp peer command
to verify that the peer's IP address is correct.
3.
If a loopback interface is used, verify that the loopback interface is specified with the
peer
connect-interface
command.
4.
If the peer is a non-direct EBGP peer, verify that the
peer ebgp-max-hop
command is configured.
5.
Verify that a valid route to the peer is available.
6.
Use the
ping
command to verify the connectivity to the peer.
7.
Use the
display tcp status
command to check the TCP connection.
8.
Check whether an ACL is applied to disable TCP port 179.
