Changing the Default SSH Port

1. Log on to the server as an administrator.

2. Open the SSH configuration file sshd_config with the text editor vi:

vi /etc/ssh/sshd_config

3. Search for the entry Port 22.

4. Replace port 22 with a port between 1024 and 65536.

5. Save the file.

6. Restart the service.

Ubuntu

service ssh restart

CentOS7

systemctl restart sshd

To establish an SSH connection after this change, enter the following command:

ssh root@IP_address_of_the_server -p NewPort

7. Set up automatic startup

systemctl enable ssh