From Boldcore's wiki
fail2ban unban IP address
Well, sometimes it happens
fail2ban-client set sshd unbanip 8.8.8.8 fail2ban-client set FILTER_NAME unbanip 8.8.8.8
Instead of FILTER_NAME there could be:
- apache
- apache-badbots
- sshd-ddos
- ... (other FILTERS)
- Please note, that f2b still does not support IPv6.