Physical Firewalls VS NAT

["Rick Darsey" <rdarsey () aims1 com>]

I am not sure if this is the right list for this question. If it is not,
please let me know where to post it.

I am doing some research for one of my clients.  They have requested a
physical firewall installed on their network.  They are already running a
NAT'ed network behind a LinkSYS router.

In this situation, what benifits, if any, will the physical firewall
provide?  The LinkSYS router already does port filtering and forwarding, and
blocks incoming WAN requests.  This is my understanding of what a firewall
does.  Granted, the firewall will be more granular, but is it necessary, or
just redundant?


Thanks

Rick Darsey
AIMS, Inc.