Im running ubuntu 10.04 and Bind9 behind a firewall. I have forwarded Ports 53 (UDP/TCP) to the local server (

The DNS system seems to be hit-and-miss when the firewall is enabled, however when I assign the server as the default DMZ server it works fine.

I do know Bind was never designed to run behind a firewall, however I am a bit weary of running the server open to the wide world all the time (I'm not a security guru, so I'm treading cautiously!)

If anyone could shed light on the situation I'd appreciate it. The server is located at (currently behind a firewall) if anyone wants a play around


  • Include the firewall configuration you use – faker Jul 26 '11 at 13:13
  • Im just running it off a dirt cheap SOHO router firewall at the moment, waiting for some new Cisco gear to arrive - there is no "configuration" to include, simply that the routers firewall is set to forward port 53 to – Brad Morris Jul 26 '11 at 13:26

Bind will use random ports to connect to the querying clients (random output ports), are you sure that they can leave the firewall without problem? Also, some providers block low port incoming connections.

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