netstat 第一次用，看不懂

Question

# netstat -a | more
 Active Internet connections (servers and established)
 Proto Recv-Q Send-Q Local Address           Foreign Address         State
 tcp        0      0 localhost:30037         *:*                     LISTEN
 udp        0      0 *:bootpc                *:*

请问

Local Address 本地地址 Foreign Address 外部地址

这两个地址代表什么意思，看不懂

Answer 1

http://en.wikipedia.org/wiki/Network_socket

An Internet socket is characterized by a unique combination of the following:

1. Local socket address: Local IP address and port number
2. Remote socket address: Only for established TCP sockets. As discussed in the client-server section below, this is necessary since a TCP server may serve several clients concurrently. The server creates one socket for each client, and these sockets share the same local socket address from the point of view of the TCP server.
3. Protocol: A transport protocol (e.g., TCP, UDP, raw IP, or others). TCP port 53 and UDP port 53 are consequently different, distinct sockets.