dns not working

when i try to do dig on my domain dia4tech.com i get this message.
connection timed out; no servers could be reached

 

cp 0 0 web1.dial4tech.c:domain *:* LISTEN 9050/mydns
tcp 0 0 localhost.locald:domain *:* LISTEN 9050/mydns
tcp6 0 0 ip6-localhost:domain [::]:* LISTEN 9050/mydns

 

What are the outputs of

Code:

ifconfig

and

Code:

iptables -L

?

 

eth0 Link encap:Ethernet HWaddr 00:0c:29:d5:89:d3
inet addr:192.168.1.123 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fed5:89d3/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:31835 errors:0 dropped:0 overruns:0 frame:0
TX packets:8788 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:3851601 (3.6 MB) TX bytes:4295223 (4.0 MB)
Interrupt:17 Base address:0x2000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:13316 errors:0 dropped:0 overruns:0 frame:0
TX packets:13316 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:998953 (975.5 KB) TX bytes:998953 (975.5 KB)

root@web1:~# iptables -L
Chain INPUT (policy DROP)
target prot opt source destination
fail2ban-ssh tcp -- anywhere anywhere multiport dports ssh
DROP tcp -- anywhere 127.0.0.0/8
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED
ACCEPT all -- anywhere anywhere
DROP all -- BASE-ADDRESS.MCAST.NET/4 anywhere
PUB_IN all -- anywhere anywhere
PUB_IN all -- anywhere anywhere
PUB_IN all -- anywhere anywhere
PUB_IN all -- anywhere anywhere
DROP all -- anywhere anywhere

Chain FORWARD (policy DROP)
target prot opt source destination
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED
DROP all -- anywhere anywhere

Chain OUTPUT (policy ACCEPT)
target prot opt source destination
PUB_OUT all -- anywhere anywhere
PUB_OUT all -- anywhere anywhere
PUB_OUT all -- anywhere anywhere
PUB_OUT all -- anywhere anywhere

Chain INT_IN (0 references)
target prot opt source destination
ACCEPT icmp -- anywhere anywhere
DROP all -- anywhere anywhere

Chain INT_OUT (0 references)
target prot opt source destination
ACCEPT icmp -- anywhere anywhere
ACCEPT all -- anywhere anywhere

Chain PAROLE (12 references)
target prot opt source destination
ACCEPT all -- anywhere anywhere

Chain PUB_IN (4 references)
target prot opt source destination
ACCEPT icmp -- anywhere anywhere icmp destination-unreachable
ACCEPT icmp -- anywhere anywhere icmp echo-reply
ACCEPT icmp -- anywhere anywhere icmp time-exceeded
ACCEPT icmp -- anywhere anywhere icmp echo-request
PAROLE tcp -- anywhere anywhere tcp dpt:ftp-data
PAROLE tcp -- anywhere anywhere tcp dpt:ftp
PAROLE tcp -- anywhere anywhere tcp dpt:ssh
PAROLE tcp -- anywhere anywhere tcp dpt:smtp
PAROLE tcp -- anywhere anywhere tcp dpt:domain
PAROLE tcp -- anywhere anywhere tcp dpt:www
PAROLE tcp -- anywhere anywhere tcp dptop3
PAROLE tcp -- anywhere anywhere tcp dpt:imap2
PAROLE tcp -- anywhere anywhere tcp dpt:https
PAROLE tcp -- anywhere anywhere tcp dpt:mysql
PAROLE tcp -- anywhere anywhere tcp dpt:webcache
PAROLE tcp -- anywhere anywhere tcp dpt:webmin
ACCEPT udp -- anywhere anywhere udp dpt:domain
ACCEPT udp -- anywhere anywhere udp dpt:mysql
DROP icmp -- anywhere anywhere
DROP all -- anywhere anywhere

Chain PUB_OUT (4 references)
target prot opt source destination
ACCEPT all -- anywhere anywhere

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

 

Can you switch off fail2ban and your firewall for testing purposes? Does it work then?
Also, does your router forward port 53 (TCP and UDP) to your server?

 

i stopped fail2ban and disabled firewall in ispconfig control panel but still not working.

 

Does your router forward port 53 (TCP and UDP) to your server?