port forwarding

Port forwarding with firewalld

linux

The firewalld in Linux is quite flexible and quite number of task can be achieve with just a single line of code. It just a matter of to get the parameter correctly.

Just to overcome the laziness of application team to change port, lets us port forwarding instead.

# firewall-cmd --add-forward-port='port=<port>:proto=tcp:toport=<toPort>:toaddr=<toAddress>'

Explanation

code

  1. Flagging firewall-cmd that this is a port forwarding rule, --add-forward-port=''
  2. Define protocol and port number that hit the host, port=<port>:proto=tcp
  3. Define destination port and address to be forwarded, toport=<toPort>:toaddr=<toAddress>

Note: Above command is to get the port forwarding work immediately after hitting enter. No need to reload service nor server reboot. The catch is, this is non-persistent configuration and as its name implies, the configuration will revert back once the OS being rebooted.