Change default SSH port

How to change the default SSH port used by your dedicated server.

Changing the default SSH port will help prevent an attacker from launching brute force attacks to the default port of your dedicated server. This method works on Linux, Ubuntu, and Debian.

Log in as the server as root, or execute sudo su to gain root access.

Check to see the status of the firewall by executing ufw status. If the firewall is active then you'll need to add a rule to allow connections for the new SSH port. This can be done by executing ufw allow <newportnumberhere>/tcp.

Execute nano /etc/ssh/sshd_config and look for the line that contains "Port 22". Change the number "22" to any unused port you'd like. Save and exit once done.

Restart the SSH service by executing restart ssh within the command line. For Debian, execute service ssh restart.

Start a new SSH session on the new port.

Delete the old firewall rule for the old port by executing ufw delete allow 22/tcp.