[c-nsp] high interrupt CPU due to traffic for IP not in arp-cache

[Iddo]

Hello All,

We are running a 6500/sup720-3BXL wit 12.2.18SXF13
A DoS attack 300,000pps was sent to an IP address which directly
connected, but not in use by a machine.
The arp entry for the target IP address is "incomplete".

This caused interrupt based CPU to 90+ %, which in turn caused
OSPF/BGP etc to timeout.

I can reproduce the results with a packetgenerator.

Can anyone recommend a solution for this?

Thanks in advance,

Iddo