I have been troubleshooting this problem for 8 hours and have not figured it out yet.
Basically, I have a 2811 where the FA0/0 keeps dropping packets at the interface now and
then seemingly when traffic tends to burst but anything over 5 megs and the errors seem to
increase. The issue is not severe enough to affect users yet but that could change as
more users generate more traffic.
Here is the interface configuration:
- 100 mbits/sec full duplex
- MTU is 1375
- GRE Tunnels are used at this interface
- No access-lists
- Proxy Arp is enabled
- Local Proxy Arp is disabled
- Fast switching is enabled
- IP CEF is enabled
- No CRC errors
- Ignore Errors increment at the same time as Throttle Errors
- Input queue: drops increment
- The input queue seems to increase to say 55 or higher and that's when we see the drops
The CPU also skyrockets at this time hitting 99%. I had a through look at the processes
show proc cpu | exclude 0.00
The processes that increase dramatically are:
- IP Input
- Pool Manager
When the CPU spikes, IP INPUT is about 60% and Pool Manager around 25 - 35% plus the rest
of the processes.
If you suspect it's some type of bursty traffic, that's fine but all SNMP stats show a
maximum rate of 6 mbits/sec - a far cry from what this router can handle.
Is it possible that there is some type of traffic affecting the router? Applications that
are running: E-mail, voice, video (OCS), ftp, mapped drives, www
The IOS is:
I reviewed all release notes / bugs and can't find anything that could be the cause.
Is it possible that the router is process-switching and slow to a crawl CPU wise? But
even if it was process-switching, we're talking about a max. of 6 mbits/sec. Besides, I
see CEF working properly (so I think anyways.)
I have this problem too.