KenHV

It can be self-hosted as well, makes it that much more appealing

This setup is the most secure, but it's also the most limiting - it's feasible only if you're hosting services for yourself or a couple of people.

I have received a lot of feedback regarding this. I'm waiting for Ubuntu to update their CIS docs for 24.04, I'll update my post when they do. I keep a lot of my blog posts regularly updated, this post will be one of them.

Fail2Ban doesn't do much for SSH other than keeping your logs cleaner if you're using key based auth. It's quite good for protecting other services like Vaultwarden for example. Of course, it's just one additional layer. The important part is to configure the services themselves to be more secure.

It might be a firewall issue or one of the Fail2Ban jails. If you're using all the Nginx jails, try disabling them and see if it fixes the issue.