I have recently setup a server with fail2ban, and it is mostly working except I am getting errors whenever this command tries to execute:
sudo iptables -D fail2ban-ssh -s xxx.xxx.xxx.xxx -j REJECT --reject-with icmp-port-unreachable
The error message is:
iptables: No chain/target/match by that name.
When I don't use REJECT, it works fine. For example:
sudo iptables -D fail2ban-ssh -s xxx.xxx.xxx.xxx -j DROP
Will execute just fine. I can't figure out why REJECT is being, er, rejected.