Step 1: To change the default SSH port, the first thing you want to do is backup the current SSH configuration on your system. To do that, run the commands below.
#cp /etc/ssh/sshd_config /etc/ssh/sshd_config.bak
Step 2: Next, run the commands below to open the default SSH configuration file
Step 3: When the file opens, make the below change and save the file. Un-comment or remove the (#) before the line the reads Port and change the port number you want to use.
Ex: Port 3306
Step 4: After that, run the commands below to allow the new port through the firewall.
# firewall-cmd –permanent –zone=public –add-port=3306/tcp
Step 5: Reload the firewall configurations
# firewall-cmd –reload
Step 6: Restart SSH by running the commands below.
# systemctl restart sshd.service
Step 7: Verify that SSH is now running on the new port by running the commands below.
# netstat -tuplen | grep -i ssh