Whenever you’re running your Linux own server on the internet, you will most probably require console access. The best idea is using SSH. This is usually on port 22. After leaving your server alone for a couple of days, you will notice that /var/log/messages fills up with incorrect logon attemps. This shouldn’t be an issue if you follow the rules:
- do not allow root acces
- use certificate authentication
- alternatively use a very very strong password
But still, it’s annoying and clogs the log. Therefore I changed the port to something non standard. Even though this is not really securing the server agains dedicated hacking attemps but it will at least keep many automated scanners away and they will leave you alone.