[tyingq]

I like pam_shield a bit better than fail2ban. It's directly tied to pam, versus trolling logs, so the configuration and operation is cleaner.

[philg_jr]

https://github.com/jtniehof/pam_shield

Last commit June 2012? Does it work with modern distros?

[tyingq]

Yes. Using it now with Ubuntu 18.04. Available via apt-get.