How to troubleshoot input queue drop continuously on Cisco7600?

> k1#sho int te1/4
>   Last clearing of “show interface” counters 00:12:35
>   Input queue: 0/200/69739/69739 (size/max/drops/flushes); Total
> output
> drops: 0

On this platform those drops could be for traffic forwarded to the CPU.
What does the interface configuration look like? Is it a L3 interface (“no switchport”), or is it a L2 interface? If the latter, and you have SVIs (VLAN interfaces) for some of the VLANs it carries, look for drops on those SVIs.

If they are “microburst” drops on L3-interfaces then you can possibly mitigate it using “hold-queue <N> in” on the L3-interfaces (SVIs or the “no switchport” interface itself). This is a trade-off; don’t use a too high setting for input-queue or you will get other problems.

You could use a SPAN session to look at what traffic might cause this.
The SPAN replication is before traffic is forwarded to the CPU so you should be able to see floods.

>   1    4  CEF720 4 port 10-Gigabit Ethernet      WS-X6704-10GE

This card has rather small queues so it might simply be microbursts. In that case you might have to find a port on another card.

For general info about input queue drops this is a good read:

Oversubscribing the card would cause output drops, not input queue drops.
As someone else mentioned, this is punted traffic.

I’d suggest using NetDR to find out.

On Mon, Oct 20, 2014 at 9:42 PM, PlaWanSai RMUTT CPE IX <> wrote: