Netstat 命令用于显示各种网络相关信息，如网络连接，路由表，接口状态 (Interface Statistics)，masquerade 连接，多播成员 (Multicast Memberships) 等等。
执行netstat后，其输出结果为
[vagrant@centos6 ~]$ netstat|more
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 10.0.2.15:ssh 10.0.2.2:52091 ESTABLISHED
Active UNIX domain sockets (w/o servers)
Proto RefCnt Flags Type State I-Node Path
unix 11 [ ] DGRAM 11021 /dev/log
unix 2 [ ] DGRAM 11556 @/org/freedesktop/hal/udev_event
unix 2 [ ] DGRAM 8986 @/org/kernel/udev/udevd
unix 3 [ ] STREAM CONNECTED 17777
unix 3 [ ] STREAM CONNECTED 17776
