[davsti4]

I've used that solution in the past. What happens when the bots start port knocking?

[dotancohen]

The bots have been port scanning me for decades. They just don't know which two ports to hit to open 22 for their IP address. Simply iterating won't get then there, and fail2ban doesn't afford them much opportunity to probe.

[GuinansEyebrows]

Fail2ban :)