Mypower
S4100
Troubleshooting
Maipu Confidential & Proprietary Information
Page
106
of
124
debug ip bgp updates: Display the receiving and sending information
about the BGP update.
BGP Troubleshooting
Fault 1: Directly-connected BGP neighbor cannot be created
Possible Reasons
Judging Methods and Solutions
BGP is different from other
IGP routing protocols. It
requires that the IP address
of the neighbor device is
available. Possible cause: the
TCP connection cannot be
created, which prevents the
communication between the
directly-connected BGP
neighbors; Wrong neighbor
IP address is configured.
How to find out the cause:
1. Use show ip bgp neighbor or show ip bgp summary
command to check whether the neighbor is created.
2) If the neighbor cannot be created, use the ping command
to check whether the peer IP address is available.
Solution:
If the link is not connected, ensure the proper connection.
Check the neighbor configuration.
If the peer IP address is unavailable through the ping
command, you can add routes to ensure that the peer IP
address is available.
TCP MD5 authentication
failed
How to find out the cause:
Use the show ip bgp neighbor or show ip bgp summary
command to find that the neighbor cannot be created but the
peer IP address is available through the ping command.
Use the debug ip tcp md5 command to check the debug
information.
Solution:
Modify the configuration and ensure it is correct.
When you use the loopback
interface to create neighbors,
the neighbors are not
configured with update-
source.
How to find out the cause:
Check whether the neighbor address is the loopback interface
address.
Check the BGP configuration. Check whether the update-
source is configured to specify the corresponding loopback
interface.
Solution:
Use the loopback interface to create the BGP neighbor. First,
you should ensure that the peer IP address is available.
Specify the source interface to the loopback interface: on the
neighbor, configure neighbor xxx update-source loopbackxx.
Fault 2: Non-directly-connected BGP neighbor cannot be created
Possible Reasons
Judging Methods and Solutions
The route to the non-
directly-connected peer
address is lost from the
routing table.
How to find out the cause:
Check whether the peer address can be pinged.
Solution:
You can add routes to ensure that the peers are connected.
