How to check my system is listening on a particular port

Linux
#1

Hello members

How can i know whether my system is listening on a particular port and what application is using that port.
I would like to know any commands that i can issue to find this out on my system.
Am using Fedora 23 and Linux Mint 17.3 if system specification is required.

Thanks

#2

Hi,
You can use:
netstat command
or
nmap

#3

Try this command my friend.

netstat -luan

i hope this help you.

#4

For system specification use dmidecode it will gives you the handy info about your system like hardware details, serial numbers and BIOS version, Processor etc

#5

Use “netstat” to check the presently using ports.

Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 xxx.xxx.xxx.xxx 0.0.0.0:* LISTEN 16297/named
tcp 0 0 xxx.xxx.xxx.xxx:53 0.0.0.0:* LISTEN 16297/named
tcp 0 0 xxx.xxx.xxx.xxx:53 0.0.0.0:* LISTEN 16297/named
tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 16297/named

#6

Hello,

You can use netstat command as below:

$netstat -taln | grep LISTEN
for listing port.
LISTEN: The socket is listening for incoming connections. Such sockets are not included in the output unless you specify the --listening (-l) or --all (-a) option.

$netstat -taln | grep ESTABLISHED
for ESTABLISHED port
ESTABLISHED: The socket has an established connection

Hope this help,

-Tiáşżn

#7

This is the output of the command, i would like to know what the second, third, fourth and fifth columns mean

#8

Proto Recv-Q Send-Q Local Address Foreign Address State

Ya, you can see :slight_smile:

1 Like
#9

@tienphan Many thanks for your help…