Description of the problem

An OSN 3500 device gateway was modified to a standby gateway on the U2000, and the network element was found to be offline.

Processing

1. Check the ECC link management of the OSN 3500 upstream site network element, and it can query the de-regulated network element, which indicates that there are no failures in the master control, optical board, and so on, of the de-regulated network element.

2. Check the ECC link management of the standby gateway network element, and the off-pipe network element cannot be queried, but the upstream station network element of OSN 3500 can be seen on the gateway, and the distance is 10.

3. On the U2000, pour the OSN 3500 device gateway back to the main gateway, the network elements can be monitored normally, open the OSN 3500 network element manager, in the ECC link management can query the main gateway and upstream network elements, but the query can not be the standby gateway network elements, a closer look at the OSN 3500 ECC link management found that the distance of the largest for the 6, and the distance to the standby gateway is 11.

4. Use the command: cm-get-maxdist to check the OSN 3500 maximum routing distance setting.

It is found that the maximum routing distance of the network element has been modified to 6. The default maximum routing distance of the network element should be 64, and after using the command cm-set-maxdist to restore the distance to 64, the OSN 3500 device is monitored normally through the standby gateway.

Root Cause

OSN 3500 maximum routing distance is insufficient resulting in going to the backup gateway and not being able to monitor it.

Solution

After changing the maximum routing distance to the default 64, it is monitored normally.

Suggestion and Summary

In the scenario where a network element cannot be monitored, if the upstream site can query the network element, you can consider whether the maximum routing restriction causes the network element not to be monitored.

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