网络通信过程中，服务器必然提供监听socket响应客户端连接请求，也必然提供连接socket与客户端进行交互。一台主机上有不止一个的socket服务器，如ftp、telnet服务器等，他们初始都处于监听状态，等待连接请求的到来。linux中为了管理这两类socket提供了两个哈希链表：tcp_listening_hash和tcp_ehash，下面主要分析下监听哈希表，顺带说下连接hash表。

-Network communication process, provide listening socket server must respond to client connection requests, it must provide connectivity to interact with the client socket. There are a host more than one socket server, such as ftp, telnet servers, they are in the initial listening state, waiting for the arrival of connection requests. linux in order to manage these two types of socket provides two hash list: tcp_listening_hash and tcp_ehash, the following analyzes the hash table under the monitor, incidentally, said that under the connection hash table.