1 former QueSO home page <URL:http://www.apostols.org/projectz/queso/>:
3 How we can determine the remote OS using simple TCP packets? Well,
4 it's easy, they're packets that don't make any sense, so the RFCs
5 don't clearly state what to answer in these kind of situations.
6 Facing this ambiguous, each TCP/IP stack takes a different approach
7 to the problem, and this way, we get a different response. In some
8 cases (like Linux, to name one) some programming mistakes make the OS
13 0 SYN * THIS IS VALID, used to verify LISTEN
19 6 SYN+XXX+YYY * XXX & YYY are unused TCP flags
21 All packets have a random seq_num and a 0x0 ack_num.