DNSiff
DNSiff is a collection of
tools for network auditing
and penetration testing.
dsniff, filesnarf, mailsnarf,
msgsnarf, urlsnarf, and
webspy passively monitor
a network for interesting
data (passwords, e-mail,
files, etc.).
GFI LANguard
GFI LANguard Network
Security Scanner (N.S.S.)
automatically scans your
entire network, IP by IP,
and plays the devil s
advocate alerting you to
security vulnerabilities.