เราสามารถใช้คำสั่ง netstat ดูรายละเอียดต่างๆของ network ได้โดยใช้คำสั่งข้างล่างนี้
[root@example ~]# netstat -tuanpeeoT
Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State User Inode PID/Program name Timer tcp 0 0 0.0.0.0:2049 0.0.0.0:* LISTEN 0 3117421 - off (0.00/0/0) tcp 0 0 0.0.0.0:1002 0.0.0.0:* LISTEN 0 3117348 12270/rpc.rquotad off (0.00/0/0) tcp 0 0 0.0.0.0:57071 0.0.0.0:* LISTEN 0 3117432 - off (0.00/0/0) tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN 0 9850 2674/portmap off (0.00/0/0) tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN 0 13340126 3009/cupsd off (0.00/0/0) tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 0 1011109 3115/sendmail: acce off (0.00/0/0) tcp 0 0 0.0.0.0:762 0.0.0.0:* LISTEN 0 9907 2700/rpc.statd off (0.00/0/0) tcp 0 0 0.0.0.0:955 0.0.0.0:* LISTEN 0 9278482 21127/rpc.rquotad off (0.00/0/0) tcp 0 0 0.0.0.0:606 0.0.0.0:* LISTEN 0 3117452 12301/rpc.mountd off (0.00/0/0) tcp 0 0 0.0.0.0:959 0.0.0.0:* LISTEN 0 9278501 21132/rpc.mountd off (0.00/0/0) tcp 0 0 172.16.44.165:54971 172.16.58.1:6667 ESTABLISHED 500 16475357 6267/xchat keepalive (6084.39/0/0) tcp 0 0 172.16.44.165:37952 10.64.69.100:22 ESTABLISHED 0 16773865 13774/ssh keepalive (589.62/0/0) tcp 0 0 172.16.44.165:33008 172.16.56.179:6667 ESTABLISHED 500 16475350 6267/xchat keepalive (6029.82/0/0) tcp 0 0 172.16.44.165:47940 203.27.221.42:6667 ESTABLISHED 500 16475327 6267/xchat keepalive (6058.69/0/0) tcp 0 0 172.16.44.165:58352 140.211.166.4:6667 ESTABLISHED 500 16475334 6267/xchat keepalive (6092.01/0/0) tcp 0 0 172.16.44.165:52042 140.211.166.64:6667 ESTABLISHED 500 16475343 6267/xchat keepalive (6028.85/0/0) ...,
รายละเอียด option ต่างๆที่ใช้
* t – Show TCP
* u – Show UDP
* a – Show both listening and established (outgoing) connections
* n – Do not do Domain lookups, show numerical addresses only
* p – Show the process associated with the connection
* ee – Show lots of extended attributes about the connections
* o – Show information about timers
* T – Do not trim long addresses