Best network scanner is nmap and it is free and runs on *nix. http://www.insecure.org/nmap
You can use npulse along with nmap which will give you the web based access. http://www.horsburgh.com/h_npulse.html nmap + npulse is simply the best. Ravi ->> network scanners on the market for finding vulnerabilities on your network, ->> reporting on issues, and suggesting fixes for the known vulnerabilities ->> that ->
