DNS

[Mattia Martinello <mattia@mattiamartinello.com>]

Hi all

I wish to open DNS connections and redirect it from the gateway and the 
server on the DMZ.
I tried these rules:

iptables -t nat -A PREROUTING -p tcp -i ppp0 -d [public IP] --dport 53 
-j DNAT --to [private IP]:53
iptables -A FORWARD -i ppp0 -d [private IP] -p tcp --dport 53 -j ACCEPT

iptables -t nat -A PREROUTING -p udp -i ppp0 -d [public IP] --dport 53 
-j DNAT --to [private IP]:53
iptables -A FORWARD -i ppp0 -d [private IP] -p tcp --dport 53 -j ACCEPT

But if I try to query my DNS server from the Internet my query goes in 
timeout.
The connections between [private IP] and the Internet are allowed (all 
other services work good without any problem, the only service that gets 
me some problems is DNS).

What have I to open to allow DNS connections from the gateway and the DMZ?

Thank you very much
Bye
Mattia