H3C LS-3100-52P-OVS-H3 Operation Manual - page 724
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Troubleshooting BGP
No BGP Peer Relationship Established
Symptom
Display BGP peer information 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 need to establish a TCP session using port 179 and exchange
open messages successfully.
Solution
1) Use
the
display current-configuration command to verify the peer’s AS number.
2) Use
the
display bgp peer command to verify the peer’s IP address.
3) If the loopback interface is used, check whether the peer connect-interface command is
configured.
4) If the peer is a non-direct eBGP peer, check whether the peer ebgp-max-hop command is
configured.
5) Check whether a route to the peer is available in the routing table.
6) Use
the
ping command to check connectivity.
7) Use
the
display tcp status command to check the TCP connection.
8) Check whether an ACL disabling TCP port 179 is configured.