There’s a myth that needs the proverbial busting treatment, and it concerns having the dreaded port 22 open.
Is it really safe to leave this back door open to your server?
I propose asking the question another way: Is it really safe to leave open a default port to the OpenSSH login system, a system protected entirely by very strong encryption and written in a manner that is designed to be as safe as possible?
If you ask it that way, I feel most people would say yes.
There is no extra security you get by running SSH on any other port than port 22. An attacker can easily run a port scan and find the port you’re running SSH on anyway. It’s a rather trivial task. If your SSH software is up to date (just like every other system-specific software on your server should be that faces the outside world), then you have nothing to worry about if your passwords are strong and/or you use SSH keys to access your server.
