This is one of the strangest things I've ever seen. We have an ASR9K (Router A) connected to a 7600 (Router B) via simple L3 link with no ACLs. We can ping from Router A to Router B, and we can ping from Router A to a different L3 interface on Router B. However, we cannot trace from Router A to that other L3 interface on Router B. That alone is weird because this is simple routing and no ACLs. That's enough of a brain teaser. However, it gets worse.
We have a network management station that is polling these routers. While the traceroute is running (and failing), the NMS can't poll the ASR9K and starts to report it as down. The NMS is polling the loopback address of the router. As soon as we stop the trace, the NMS starts getting replies from Router A again. So, two brain teasers: 1. Why would trace fail where ping succeeds? There are no ACLs, so this really stumps me. We do not have CoPP configured. 2. While the trace is failing, why would our NMS stop getting replies from the ASR9K? I honestly don't know what to think about this. I don't think I've ever seen anything like it. Any thoughts? _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
