Sereval Basic Linux Netstat Command

Posted by Wei Xia on April 10, 2017 | Hits:

What is Netstat?

In computing, netstat (network statistics) is a command-line network utility tool that displays network connections for the Transmission Control Protocol (both incoming and outgoing), routing tables, and a number of network interface (network interface controller or software-defined network interface) and network protocol statistics.

List out all connections

The most simple command is to list out all the current connections by using: netstat -a


$ netstat -a

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
tcp        0      0 enlightened:domain      *:*                     LISTEN     
tcp        0      0 localhost:ipp           *:*                     LISTEN     
tcp        0      0 enlightened.local:54750 ESTABLISHED
tcp        0      0 enlightened.local:49980 del01s07-in-f14.1:https ESTABLISHED
tcp6       0      0 ip6-localhost:ipp       [::]:*                  LISTEN    

Get process name/pid and user id

When viewing the open/listening ports and connections, its often useful to know the process name/pid which has opened that port or connection. You can use the following command: sudo netstat -nlpt


~$ sudo netstat -nlpt
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0  *               LISTEN      1144/dnsmasq    
tcp        0      0 *               LISTEN      661/cupsd       
tcp6       0      0 ::1:631                 :::*                    LISTEN      661/cupsd


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