I found this:

Throttles - When the Input Q (process switching) fills up on an interface,

the CPU assumes that something is misbehaving on that interface (broadcast

storm, SNMP storm) since the processor is not able to keep up with the

incoming packet rate (hence the Q filling up). The processor throttles the

interface to protected itself and the other well-behaved interfaces. This

means that it ignores interrupts from that particular interface for one

second. When the interface gets a packet and sends an interrupt to have it

stored and switched, the processor doesn't answer. Thus the packet is

dropped at the hardware level. Throttled means interrupts were disabled for

the interface. We do this for any interface when the input queue is filled.

Packets in the input queue are processed before interrupts are enabled

again, so no traffic will enter the port.

You can increase the input

queue, but if they still happen, look at the switching path, and see if you

can fast switch traffic without causing some other problem. If the Input Q

never returns to 0, then you might have packets stuck in the Q. In that case

you can do a 'show buffer old' or 'show buffer input-int xx' to find out

what packets are stuck. There is no counter that keeps track of how many

packets were dropped during the throttle interval.

First of all please try to increase the Input Queue on the fastethernet

interface as follows.

config t

int fa1/1

hold-queue 120 in

Also u may post this in the Routing forum so some experts in that area can help us as well.