DNS on the internet... how to allow connections?
Hi there,
I solved all of my routing problems which I had before... Now everything works fine, but the name resolution. According to the scheme (Trusted subnet -> Firewall -> Internet), hosts on my trusted subnet can see the DNS properly, they get its address from the DHCP, but they cannot get DNS queries satisfacted.
I tried with different rules, but none works:
$IPTABLES -A INPUT -p tcp --dport 53 -j ACCEPT
$IPTABLES -A OUTPUT -p tcp --dport 53 -j ACCEPT
$IPTABLES -A INPUT -p udp --dport 53 -j ACCEPT
$IPTABLES -A OUTPUT -p udp --dport 53 -j ACCEPT
or these:
$IPTABLES -A FORWARD -p tcp -s $DNS1_IP -j ACCEPT
$IPTABLES -A FORWARD -p tcp -s $DNS2_IP -j ACCEPT
$IPTABLES -A FORWARD -p udp -s $DNS1_IP -j ACCEPT
$IPTABLES -A FORWARD -p udp -s $DNS2_IP -j ACCEPT
Do I have to setup my own named, cache queries and requests new ones if I need? Or it is just my problem, that I am not able to write rules...?
Thanks in advance
Marco Nicoloso
Marco -- yer on the right track -- read in line....
Quoted 7 lines · Marco Nicoloso
Hi there,
I solved all of my routing problems which I had before... Now everything works fine, but the name resolution. According to the scheme (Trusted subnet -> Firewall -> Internet), hosts on my trusted subnet can see the DNS properly, they get its address from the DHCP, but they cannot get DNS queries satisfacted.
DNS queries -- okay - unless the DNS is on the same box as the firewall you
want to :
Quoted 4 lines
I tried with different rules, but none works:
$IPTABLES -A INPUT -p tcp --dport 53 -j ACCEPT
$IPTABLES -A INPUT -p udp --dport 53 -j ACCEPT
Change INPUT to FORWARD
and try again...
Quoted 6 lines
or these:
$IPTABLES -A FORWARD -p tcp -s $DNS1_IP -j ACCEPT
$IPTABLES -A FORWARD -p tcp -s $DNS2_IP -j ACCEPT
$IPTABLES -A FORWARD -p udp -s $DNS1_IP -j ACCEPT
$IPTABLES -A FORWARD -p udp -s $DNS2_IP -j ACCEPT
Loose the above and use an ESTABLISHED, RELATED rule to accept the returns.
Quoted 2 lines
Do I have to setup my own named, cache queries and requests new ones if I need? Or it is just my problem, that I am not able to write rules...?
Nope -- just let the queries THROUGH the firewall -- not in or out.
Alistair
Quoted 4 lines
Thanks in advance
Marco Nicoloso