fail2ban

Checking if someone is in jail

You have multiple jails - the one I'm usually interested in is sshd:

sudo fail2ban-client status sshd

• How to show all banned IP with fail2ban? - Server Fault

Removing from jail

sudo fail2ban-client -i

then in interactive mode:

status sshd
set sshd unbanip XXX.XXX.XXX.XXX

• firewall - How to Unban an IP properly with Fail2Ban - Server Fault