My pc is running Windows server 2003 sp2. Whenever I establish an internet connection (e.g., with internet explorer to google.com), my host sends the syn packet twice. It is (probably not) a retransmit as the two syn packet are sent within a 0.01 ms interval (according to wireshark timestamping).
I wrote a short java program that simply do a socket.connect and I have the same thing, but if I run the program on another machine (with Windows XP), it is fine (no duplicate syn).
Anyone has a clue what this is about ?
A bit more data: When I initiate a tcp connection with google.com, my pc sends 2 syn, then I get only 1 syn/ack (which I think is normal), but then, my pc will send the ack twice as well.
Any help is welcome !