1 point
To add to this, install fail2ban (most distros have it in their package system) and activate it for the various things that use username/passwords in your system.
Basically it monitors access logs and blocks the IPs that repeatedly fail logins.l for a certain amount of time.
This drastically reduces the effectiveness of brute force attempts - as long as your password isn’t, “password” and guessable in one go.
