Well, fail2ban is killing their attempts. CSF would similarly block them as well.

For the sake of reducing log entires and emails, you may want to have SSH listen on a port other than 22.

You could edit your /etc/ssh/sshd_config file and change the Port line to be a different port, say like 9022. Most importantly, you’ll need to make sure your software firewall has this port open. Then you’ll want to restart the ssh process.

This will not make you more secure or make it impossible for someone to attempt to log into your server. It’s going to reduce the attempts making it easier to read through logs and email alerts.

@jschwenn thanks for the tip. I m still learning linux command.I have tried changing it on /etc/ssh/sshd_config but , many request like apache2 came up with error. likewise i dont know how many services do require that port. i had to turn off my ufw because eachtim its on, the website goes offline.
is there something I am actually supposed to watch for?