Troubleshooting bgp, Bgp peer relationship not established, Symptom – H3C Technologies H3C S12500 Series Switches User Manual
Page 285: Analysis, Solution
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Routing Table : Public
Summary Count : 1
Destination: 1.1.1.0/24
Protocol: BGP Process ID: 0
Preference: 0 Cost: 100
NextHop: 2.0.1.1 Interface: Vlan-interface201
BkNextHop: 0.0.0.0 BkInterface:
RelyNextHop: 2.0.2.1 Neighbor : 2.0.1.1
Tunnel ID: 0x0 Label: NULL
State: Active Adv Age: 00h09m54s
Tag: 0
The output shows that Switch A and Switch C communicate through Switch D, and Switch C has
one route Switch C<—>Switch D<—>Switch A to reach network 1.1.1.0/24.
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 test the connectivity to the peer.
7.
Use the display tcp status command to verify that the TCP connection is normal.
8.
Verify that no ACL is configured to disable TCP port 179.