General Tools
WintelGuy.com: all kinds of network tools
Bandwidth-Delay Product Calculator
Traffic Generation (TCP Replay)
Taps and SPANs
Operating Systems
Guidelines for Improving Microsoft Network Performance
Request For Comments (RFCs), Etc.
RFC Editor USC Information Sciences Institute.
IAB Internet Architecture Board, Technical Advisory Organization
IANA Internet Assigned Numbers Authority.
IETF Internet Engineering Task Force, Technical Contributory Organization.
ISOC Internet Society, Professional Organization.
Protocols
Security
Test if your HTTP server is using low-tech Base 64 password encryption
Worms, Honeypots, Etc.
Fighting Internet Worms With HoneyPots