fail2ban not working as expected

Question

after several intentional unsuccessful login attempts fail2ban has banned me from my server but I am still able to log in afterwards.

# iptables -L  
Chain INPUT (policy ACCEPT)
target prot opt source destination
fail2ban-ssh tcp -- anywhere anywhere multiport dports ssh

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

Chain fail2ban-ssh (1 references)
target prot opt source destination
DROP all -- dslb-xx-xx-xx-xx.pools.arcor-ip.net anywhere
RETURN all -- anywhere anywhere 



cat /var/log/fail2ban.log  
Ban xx.xx.xx.xx  
xx.xx.xx.xx already banned


ssh [email protected] -p yyyyy  
user's password:************  
Linux hostname 2.6.26-2-amd64  
user@hostname:~$

So fail2ban tells me I am banned but I can still log in.
Any hints?

Here is the whole output of "iptables -L"

Chain INPUT (policy ACCEPT)
target     prot opt source               destination
fail2ban-ssh  tcp  --  anywhere anywhere        multiport dports ssh  

Chain FORWARD (policy ACCEPT)  
target     prot opt source               destination    
Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
Chain fail2ban-ssh (1 references)  
target     prot opt source               destination
DROP       all  --  dslb-xx-xx-xx-xx.pools.arcor-ip.net  anywhere  
RETURN     all  --  anywhere             anywhere

Answer 1

In the file /fail2ban/jail.conf edit the following :

[ssh]

enabled  = true
filter   = sshd
action   = iptables[name=SSH, port="yyyy,ssh", protocol=tcp]
logpath  = /var/log/sshd/current
maxretry = 3

I've seen you were using an alternative port for ssh so, replace the yyyy be the port the sshd deamon is running.

Then restart fail2ban.