Input queue drops.

[phowlett549]

Hello, we are running several virtual router interfaces on our MSFCs in our 6500 switches. We are experiencing a high level of droped packets on some of them indicated in the show interface command. E.G.

Input queue: 0/75/626738/0 (size/max/drops/flushes)

We don't appear to be experiencing any problems on the network but I woud like to be able to discover the cause and ideally rectify it.

[jolmo]

Please, read this:

http://www.cisco.com/en/US/products/hw/routers/ps133/products_tech_note09186a0080094791.shtml#topic2

HTH

[Georg Pauwen]

Hello,

you might want to check this document:

Troubleshooting Input Queue Drops and Output Queue Drops

http://www.cisco.com/warp/public/63/queue_drops.html

Also, do a search on Google for 'input queue drops', there are numerous discussions in user groups that deal with this.

Regards,

GP

www.solutionfinders.nl

[phowlett549]

Hi, thanks. I had previously looked at these articles but the information points towards physical as apposed to logical interfaces. I have followed the steps but cannot pin down a congested interface at present. We are also running MLS. I did notice quite a high number of 'bad hop count' when I executed a show ip traffic command- any ideas?

Thanks.

[lrian]

Unless you have "no icmp unreachable" configured on the vlan interfaces all those pkts with a bad hop count get sent to the MSFC so it can send an icmp ttl expired.

Something else to look at would be access lists on the MSFC that can't be done in hardware. Like having the "log" keyword at the end. Anything being logged has to be punted to the MSFC.