Write all login attempts to syslog for integration with fail2ban.
I spent quite a lot of time troubleshooting the setup. It's not mentioned in the readme but the plugin may need to tweaking depending on your OS. For CentOS 6, I had to change the jail conf to monitor /var/log/messages. I did not have to change any of the plugin PHP code as someone mentioned in the forum (threw me off since I did it).
Also, I never got fail2ban to trigger the ban action even though it was regex matching (apparently a common issue). I ended up going with CSF LFD to ban per http://forum.configserver.com/viewtopic.php?f=6&t=6663#p20069
As my server already had fail2ban, this was just the perfect plugin from brute force attacks!
The configs suggested in the help did not work, so minor tweaking were needed.