I am trying to write a little NAT service, and i need to change ip packets. (The source address, source port, and the checksum of the packet.)
Where/how do i do it? In winsock.h (mayby il do it in linux... dont know yeat). Is it done in/with Tcp/ip using sockets?
What sould i read or buy?
Pleas healp one whery cold Icelander