An IP-address that was blocked by fail2ban
can be unblocked using the following method.
Get a list of all blocked addresses:
iptables -L -n
This will display all settings in the iptables
firewall. For fail2ban
there will be a section like this at the bottom:
Chain fail2ban-ssh (1 references)
target prot opt source destination
RETURN all -- 0.0.0.0/0 0.0.0.0/0
The remove the IP <IP-ADDRESS>
from the blockade:
iptables -D fail2ban-ssh -s <IP-ADDRESS> -j DROP
Source: Unblock IP from Fail2Ban