The SS is the abbreviation for the socket statistics. As the name implies, the SS command can be used to get socket statistics, which can display and netstat similar content. But the advantage of the SS is that it can show more and more detailed information about TCP and connection status, and is faster and more efficient than netstat.
When the number of socket connections for a server becomes very large, the execution speed is slow, either with the netstat command or the cat/proc/net/tcp. You may not have a personal feeling, but please believe me, when the server maintains a connection of tens of thousands of times, the use of netstat equals wasting life, and the SS is to save time.
The World martial arts only fast not broken. The secret of SS Quick is that he took advantage of the TCP protocol stack in Tcp_diag. Tcp_diag is a module for analyzing statistics that gives you first-hand information in the Linux kernel, which ensures the fast and efficient SS. Of course, if you do not have tcp_diag,ss in your system, you can run normally, but the efficiency will become slightly slower. (but still faster than Netstat.) )
Usage examples:
Example 1: Displaying a TCP connection
Command: Ss-t-A
Example 2: Display sockets summary
Command: Ss-s
Lists the current established, closed, orphaned, and waiting TCP sockets
Example 3:
Ss-l
Example 4: View the socket used by the process
Command:
Ss-pl
Example 5: Find out the open socket/port application
Command:
Ss-lp | grep 3306
Example 6: Show all UDP sockets
Command:
Ss-u-A
Example 7: Show all SMTP connections with established status
Command:
Ss-o State established ' (Dport =: SMTP or sport =: SMTP) '
Example 8: Show all HTTP connections with established status
Command:
Ss-o State established ' (Dport =: http or sport =: http) '
Example 9: Enumerate all TCP sockets in the Fin-wait-1 state where the source port is 80 or 443 and the destination network is 192.168.1/24
Command:
Ss-o state fin-wait-1 ' (sport =: http or sport =: HTTPS) ' DST 192.168.1/24
Example 10: Filtering Sockets with TCP status:
Command:
Ss-4 State Filter-name-here
Ss-6 State Filter-name-here
Filter-name-here can represent any one of the following
Established
Syn-sent
Syn-recv
Fin-wait-1
Fin-wait-2
Time-wait
Closed
Close-wait
Last-ack
Listen
Closing
All above states
Connected all states except listen and closed
Synchronized all connected states in addition to Syn-sent
Buckets show states as maintained as minisockets, such as time-wait and SYN-RECV.
Big and bucket opposite
Example 11: Matching remote address and port number
Command:
SS DST Adderss_pattern
SS DST 192.168.1.1
SS DST 192.168.1.1:8080
Example 12: Matching local address and port number
Command:
SS Src Address_pattern
SS Src 192.168.1.1
SS Src 192.168.1.1:80
Example 13: Compare a local or remote port to a number
Command:
SS Dport OP Port remote port and a number comparison; destination port
SS Sport OP Port Local port and a number comparison; source port
Op--option:
<= or LE, >= or ge, = = or EQ,
! = or NE < or GT > or LT
Example 14:SS and netstat efficiency comparison
Command:
Time Netstat-at
Time SS
Use the time command to obtain, respectively, the Times used by the Netstat and SS commands to get the resource occupied by the program. When the number of server connections is more, netstat efficiency is completely unable to compare with SS.
Source: https://www.cnblogs.com/aaronax/p/5664719.html
Log linux commands (20180424)-SS command