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FREQUENTLY ASKED QUESTIONS

Question

What does "There was no path at the IP layer" mean in the CP web report?

Answer

You may see this phrase in the CP web report as a failure reason for some unroutable traffic. This message means that the CP determined that the source and end devices could not communicate at the IP layer. The reason for this failure to communicate may not be immediately obvious, but there are a few things that you can check. First, have all of the intermediate nodes and links been created? If they have and it appears that there is a physical path, then it is most likely a configuration problem. Were there any lower layer circuit failures? For example, if the IP traffic was depending on a Promina connection between some of the intermediate IP routers, the routers will not be able to communicate if the circuit fails.

If there were circuit failures, look at the circuit failure reasons and correct those problems first. Finally, check for other types of configuration errors. For example, if there is a satellite connection between two intermediate routers, make sure the satellite link's ports match the earth terminal ports to which the routers are connected. If you still don't see the cause of the problem, try to narrow in on the cause by routing IP flows between each of the intermediate routers in the path. By seeing which of those are unroutable, you should be able to discover the point at which the traffic is failing and then take a close look at that area.

Another good technique for discovering the problem is to look at the different layers in the logical views. Is there an unexpected lack of connectivity at one of the lower layers? If so, that could be the cause of your IP layer troubles.