I need to support multiple roaming users. Manually maintaining whitelists would be a burden. Fail2ban isn't a firewall. It monitors logs for suspicious activit

I need to support multiple roaming users. Manually maintaining whitelists would be a burden. Fail2ban isn't a firewall. It monitors logs for suspicious activity and responds with an action (not limited to banning an IP). When you expose services publicly, it's one of many tools you can use to limit bad behaviour without penalizing or inconveniencing legitimate users. I also use iptables (including the recent and string modules), RBLs, and a host of other access controls. Security is a layered approach and redundancy isn't a bad thing.