[c-nsp] ASR920 stops routing unexpectedly

[Eric Van Tol]

Hi all,
I am now on my third day with TAC on this problem and they are driving me up a wall. I have an ASR-920-24SZ-M that has been in service for almost a year, on 3.15.0S running ISIS, BFD on one link, BGP, LDP, MPLS. Shortly after midnight this past Saturday, it stopped routing for no apparent reason. As we have it connected to an ethernet OOB network, I was able to get in it to take a look. 

The first thing we see is that BFD on one of the upstream links times out. Then *every* ISIS session on the router goes down and it stops processing ISIS updates. All the interfaces were up/up and doing a shut/no shut on them did not bring ISIS back up. Unfortunately, I wasn't thoughtful enough to do a simple ping across them to see if they were processing *anything*. The only way to recover appeared to be a reboot.

I'd chalk that up to a "network anomaly", but the following night it happened again right around the same time. Again, in my rush to get everything back up and running, I had to reboot it before I could gather much information (ie. no ping, like an idiot).

I'm running 3.15.0S, but don't want to upgrade without knowing what this is. I found this link to an old discussion: 

http://www.gossamer-threads.com/lists/cisco/nsp/191739#191739

But TAC is ignoring my request for details on this bug. The first level TAC engineer keeps focusing on the upstream link, completely ignoring the fact that the router stops processing routing protocol updates. Anyone else experience this kind of weirdness with the ASR? And if so, what can I tell the next TAC engineer in order to get past this "it looks like a link failure" tunnel vision bullshit that they so often like to have? 

-evt