Mastering Linux Security and Hardening - Second Edition

Changing the default SSH port

By default, SSH listens on port 22/TCP. If you've been around for a while, you've surely seen plenty of documentation about how important it is to use some other port in order to make it harder for the bad guys to find your SSH server. But, I must say, this notion is a bit controversial.

In the first place, if you enable key authentication and disable password authentication, then changing the port has limited value. When a scanner bot finds your server and sees that password authentication is disabled, it will just go away and won't bother you anymore. In the second place, if you were to change the port, the bad guys' scanning tools can still find it. If you don't believe me, just go to Shodan.io and search ...