Banned internet provider IP address By Fail2ban?

Question

I cant access my webserver from several IP adress. And i think the problem might be in iptables.

I have fail2ban installed on a server and maybe that is the reason.

My webserver runs under ubuntu 13.10

IPTABLES -L gives me the next:

root@mail:/home/irishman# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
fail2ban-postfix  tcp  --  anywhere             anywhere             multiport dports http,https,smtp,submission,pop3,pop3s,imap2,imaps,sieve
fail2ban-dovecot  tcp  --  anywhere             anywhere             multiport dports http,https,smtp,submission,pop3,pop3s,imap2,imaps,sieve
fail2ban-roundcube  tcp  --  anywhere             anywhere             multiport dports       http,https,smtp,submission,pop3,pop3s,imap2,imaps,sieve
fail2ban-ssh  tcp  --  anywhere             anywhere             tcp dpt:ssh

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         

Chain fail2ban-dovecot (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain fail2ban-postfix (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain fail2ban-roundcube (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain fail2ban-ssh (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere   

I can't see any banned adress there. But the problem remains. I can access my server with one internet provider and can't with another.

Also i have calmAV installed(can it be the reason?)

Answer 1

As you say, it looks like fail2ban isn't your problem. Just to check, try stopping the fail2ban service (service fail2ban stop) temporarily, which will remove any iptables restrictions in place, and see what happens.

The next thing to try is traceroute from some of the hosts that can't reach the server, and see if there's a common place where they get stuck - you can occasionally get routing problems, especially if your web server is on a recently-allocated block of IP addresses.