To make it even better, you can edit /etc/hosts.deny and specify / authorise only specific IP address or address to access the Server. you can access the server using a VPNs with a static IP address. Only the IP addresses would be allowed to log in other would be blocked. Scroll to the end when you edit /etc/hosts.deny and add:
sshd: ALL EXCEPT xx.xx.xx.xx, xx.xx.xx.xx, xx.xx.xx.xx
where xx.xx.xx.xx IPs allowed to access server.