TCPIP全部源代码，共有上百个C程序，是份内容最丰富的资料。-TCPIP all source code, there are hundreds of C procedures, content is the most abundant information.

关于TCPIP的首部校验和的计算，一点关于IP校验和的文档，希望对大家帮助。-On TCPIP the first checksum is calculated, a little bit about the IP checksum of the document, we want to help.