This page is about Port management on Linux.
When you install a software (process), you need often to verify the available port in order to configure the component installation.
with netstat, you can check port.
For example, below, you can see that the port 1521 is used to the program tnslsnr (The -p parameters means program and is mandatory)
netstat -tulpn | grep 1521
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Protocol Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 :::1521 :::* LISTEN 4264/tnslsnr
where:
with Network - netcat (nc, ncat)
nc -zv hostname port
DNS fwd/rev mismatch: hostname != hostname.lan
hostname [192.168.135.6] 9000 (?) open
To see the port used by services, you can inspect the services file (The services translation file), located at:
/etc/services