LAN auditing???

From: John (John@nospam.msn.com)
Date: 09/30/02 

From: "John" <John@nospam.msn.com>
Date: Mon, 30 Sep 2002 08:17:31 -0700

Hello everyone! I was wondering if anyone had any ideas,
or knew about a product that would allow a good thorough
security audit of my LAN.

I just took over the position on network admin at my
company, and the person that I am replacing wasn't that
security smart. I basically want to go over every bit of
the network and look for backdoors and stuff like that.

We have Norton Anti-Virus, and that seems to get most of
the main virus's. Is there anything else that I should do
as far as auditing?

TIA'
John