running novell 6.0 sp5
named.nlm version 5.12F
PIX-515 cisco

school district

the pix gets flooded with requests from one server and brings the internet
down to a crawl.
I unload named.nlm
outside vendor clears the pix
I reload named.nlm
and the internet is fine.

any ideas what could be causing this or what to look for ????
happens a few times a week in the morning hours...