Linux has high security and stability, and is very suitable for domestic or overseas server operating systems. After we open the server, we usually need the server IP address, port and account information to log in to manage the server. For the sake of security, the default port is often modified first. Let's take a look at the steps to modify the default remote port of the server
Edit sshd_ Config file, add port 123. Port 22 is not deleted here to avoid forgetting to add firewall exceptions, which may cause the host unable to connect.
vi /etc/ssh/sshd_ config
Uncomment Port22 and add a new line Port22
Add Firewall Exception
firewall-cmd --zone=public --add-port=123/tcp --permanent
firewall-cmd --reload
Or turn off the firewall
Centos off:
Systemctl stop firewall
Systemctl start firewall
Debian system:
Ufw enable//Enable
Ufw disable//Close
Ubuntu off:
Sudo ufw enable
Sudo ufw disable
Restart service
systemctl restart sshd
Test adding 123 port connections. After normal operation, you can delete sshd_ Port22 in config file
