Hello there, Community
This post is about the ECC Storm. Please see more details about this topic as you read further down.
ROOT CAUSE
The root cause of the ECC storm is that the ECC itself is not suitable for large-scale networking. The networking is too large, and the route calculation is degraded. When the network changes, the route broadcast information is continuously broadcasted throughout the network, causing the route to be recalculated continuously, causing the routing table to converge. The time is too long.
SOLUTION
Method 1
The method for solving the ECC storm fundamentally is ECC division. In the case of ensuring performance, 64 network elements are required to be equal to or less than 80 network elements. Then how to judge that an ECC storm has occurred, this can be judged by the phenomenon. When an ECC storm occurs, a large network element is taken off, but the gateway network element does not go out of control, and the ECC routing table is repeatedly queried on the gateway network element. The number of target NEs returned is different each time, so it can be confirmed that it is an ECC storm.
Decompression caused by ECC storm, if it is not long-term recovery, it is not recommended to deal with it. The solution to ECC storm is to carry out ECC giant network segmentation; if it does not recover for a long time, you can use temporary recovery method: you can use "ecc- Set-maxdist: length" / "cm-set-maxdist: length" to set, the default length is 64, you can modify the distance to be small, and then gradually increase, Until it returns to normal.
Method 2
The second method is to close the corresponding ECC link of the network element of the backbone node, and then gradually restart after the network converges. The ECC is divided, but there are also ECC storm networks. There are two possibilities. Firstly, the DCN of the central office causes the two ECC subnets to be interconnected by the extended ECC. At this time, the extended ECC processing of the gateway NE is closed.
Secondly, the interconnection of different networks leads to ECC interworking. For example, the local network can communicate with the provincial or national network elements, and the ECC of the docking optical board can be closed.
