Use ss in CentOS to view network port status

[Scenario 1: View network connection statistics of the current server] $ ss-sTotal: 295 (kernel312) TCP: 48 (estab1, closed31, orphaned0, synrecv0, & nbs

[Scenario 1: view the network connection statistics of the current server]

$ ss -sTotal: 295 (kernel 312)TCP:   48 (estab 1, closed 31, orphaned 0, synrecv 0, timewait 0/0), ports 13Transport Total     IP        IPv6*         312       -         -RAW       0         0         0UDP       2         2         0TCP       17        12        5INET      19        14        5FRAG      0         0         0

When the server generates a large number of sockets connections, we will use this command for macro statistics.

 

Scenario 2: View all open network ports]

$ ss -lRecv-Q Send-Q           Local Address:Port               Peer Address:Port0      128                         :::webcache                      :::*0      128                         :::http                         :::*0      128                         :::snapenetio                      :::*0      128                          *:snapenetio                       *:*0      50                           *:8531                          *:*0      9                           :::ftp                          :::*0      9                            *:ftp                           *:*0      128                          *:ddi-tcp-1                       *:*0      100                        ::1:smtp                         :::*0      100                  127.0.0.1:smtp                          *:*0      128                          *:8541                          *:*0      128                  127.0.0.1:entextxid                       *:*0      50                           *:12421                         *:*0      10                           *:amqp                          *:*0      128                          *:12521                         *:*0      50                           *:mysql                         *:*

If the-pl parameter is used, the specific program name is listed. You will see something similar to this in the output:

("nginx",15786,6)

We can know that a socket connection belongs to the nginx program, and the PID of the nginx program is 15786.

 

[Scenario 3: View All socket connections on this server]

You can simply use the-a option to list all network connections.

#ss -a

If you only want to view TCP sockets, use the-ta option;
If you only want to view UDP sockets, use the-ua option;
If you only want to view RAW sockets, use the-wa option;
If you only want to view UNIX sockets, use the-xa option.