Is-is neighbor cannot establish problem instance resolution

Is-is neighbors cannot establish the following troubleshooting:

Network environment

The Is-is routing protocol is run between two NE80, and a Ip-trunk interface is connected through the transmission via 3 2.5G POS interface. Ip-trunk link status is up, two NE80 devices can ping each other, but cannot establish is-is neighbor relationship.

Fault analysis

There may be several reasons for this

Is-is configuration is inconsistent on step 12 devices.

Step 22 device versions are inconsistent, resulting in mismatched is-is messages.

Step 3 There is a problem with intermediate transmission links or ip-trunk links.

Processing steps

Step 1 Executes the command display current-configuration on the two NE80 devices to see if Is-is is enabled on the interface. If not, use the ISIS enable command in the interface view to Is-is.

Step 2 Execute command on two NE80 devices display ISIS brief, respectively, check the Is-is configuration of two devices, found that both NE80 are running in the Level-2 area, and Ip-trunk interface can be Is-is, both ends of the device configuration is not a problem.

Step 3 Execute command on two NE80 devices display ISIS interface, check the version of two devices, the two versions are exactly the same, indicating that the problem exists on the link.

Step 4 Check the links in the middle of two NE80 devices to ping, but there is an inconsistency in the number of active members on both ends of the trunk link, and the number of active members of the Ip-trunk interface of two NE80 devices is modified in the same way. Is-is can function properly and establish a neighbor relationship.

Case summary

Ip-trunk Interface link state up, but the number of active members are inconsistent, it is easy to cause links can ping, but the protocol or partial forwarding traffic loss, because the ping packet selected member port and protocol selected member port inconsistent. Ip-trunk or eth-trunk should pay attention to the above problems.