3 ms·
1. As others have suggested, read W. Richard Steven's book (http://smile.amazon.com/Unix-Network-Programming-Sockets-Networking/dp/0131411551/ref=la_B000AP9GV4_
by TYPE_FASTER 12y ago
1. As others have suggested, read W. Richard Steven's book (http://smile.amazon.com/Unix-Network-Programming-Sockets-Networking/dp/0131411551/ref=la_B000AP9GV4_1_1?s=books&ie=UTF8&qid=1428190860&sr=1-1 http://smile.amazon.com/Unix-Network-Programming-Sockets-Net...).
2. Read the HTTP spec.
3. Write a simple server, send requests through some commonly encountered firewalls, proxy servers, etc. while running Wireshark on the client and server sides and see what happens to your request and response data. One popular antivirus program used to (and maybe still does) rewrite HTTP headers.