[c-nsp] Cisco 6500 experiencing %CPU_MONITOR-SP-6-NOT_HEARD

j.vaningenschenau at utwente.nl j.vaningenschenau at utwente.nl
Wed Jun 16 09:03:32 EDT 2010


Hi Yousef,

> Just for the record, I will post this in case some guys out there
> have the 
> same problem some day.
> 
> Last friday, one of my core routers, a Cisco 6509 with two SUP720-3BXL
> modules running s72033-advipservicesk9_wan-mz.122-33.SXH2a, crashed
> and 
> restarted out of the blue.
> 
> Crashfile info says the following :

-=snip=-

> Personally, I'd say I hit a bug with this but I can't seem to find it
> using 
> cisco web tools. Anyone could point me to the right direction ?

We had similar crashes in 2007-2009 (on SUP720-3B). After several *long*
TAC cases, it turned out that we hit a couple of bugs. I can't find the
bug IDs at the moment, but according to my email archive, the fixes were
included in SXH4.

I'd recommend trying a more recent SXH build as a lot of issues have
been fixed since SXH2a. Or, if you're comfortable with bigger upgrade
steps: we're running SXI3a now, which has been more stable in our
environment than SXH has been. However, as always with bugs & features
in IOS, YMMV.

By the way, the root cause in our case had to do with interrupt masking;
it was mainly triggered by non IP packets from directly connected
network segments. Our case was only reproducible by replaying actual
traffic captures, not with "synthetic" IP traffic.


Regards,

Jeroen van Ingen
ICT Service Centre
University of Twente, P.O.Box 217, 7500 AE Enschede, The Netherlands



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