The commands presented above can be executed using:

$ fail2ban-client <COMMAND>

or by typing them in the interactive console available with:

$ fail2ban-client -i

Manually Unban a <IP> address in <JAIL>:

$ fail2ban-client set <JAIL> unbanip <IP>

For sshd jail:

$ fail2ban-client set sshd unbanip 10.12.112.1

Manually ban a <IP> address in <JAIL>:

$ fail2ban-client set <JAIL> banip <IP>

For sshd jail:

$ fail2ban-client set sshd banip 10.12.112.1

http://www.fail2ban.org/wiki/index.php/Commands