TCP fingerprinting works by sending TCP packets to a port and
noticing how the TCP stack responds… each vendor implements the
TCP/IP stack a little differently….
The first such tool to hit the Internet was Queso, which runs on
Linux only [and]… was released to the public domain in early
October…
Security heavyweights Network Associates (NAI) and Internet
Security Systems (ISS) are also planning to build this technology
into their products…