Hello forum, We very successfully use FreeBSD 8.3 as our gateways at multiple locations. Currently our clients and servers run MS Windows (XP, 7, Server 2003). With over 500 client PC's we have tried using Trend Micro and Symantec Pro as the client ati-virus. Both have failed to stop infections (and yes, the definitions were up to date). The tipping point came two years ago when Symantec offered to remove a virus for a fee. We do not provide users with "admin" or "power user" privileges, so virus removal after an infection is very easy (malwarebytes). We wanted a better solution. We now use the free "Microsoft Security Essentials" software and our infection rate is still about the same as using the other paid for solutions. My main concern is any information transmitted by a virus. Any ideas or thoughts on using nmap to look for PC's transmitting on non-standard ports. I would also like to hear how you are dealing with this issue. I would also add that we don't look for "free" software just the best solution.