DNS responder fails - why and how to fix it?

[James Bond]

Recently, I have started to get the following message on the Console. It started since I moved the mac from behind a NAT router into the DMZ. Had to do this to get iChat to work. Firewall in on and correctly set up per Apple guidelines.

Symptom is that nothing that uses DNS works any more.

Apr 2 04:06:57 FlatScreen mDNSResponder[202]: mDNSPlatformSendUDP sendto failed to send packet on InterfaceID 01807000 en0/4 to 224.0.0.251:5353 skt 4 error -1 errno 13 (Permission denied)

What causes this and how to fix/avoid it?

Using 10.3.3 and 512MB

[btoneill]

mDNSResponder is used with Rendezous and is used for name discovery/reponses on a network that has other hosts using Rendezous. So, mDNSResponder isn't responsible for your normal DNS stuff. Are you sure now that you're in the DMZ you can access a DNS server? What does 'host www.gnu.org' tell you from a command line? What is listed in /etc/resolv.conf?

Brian

[James Bond]

Indeed. I think that possibly the error message that I note is a consequential one and not the real probem. At the moment all is fine, so I will wait for the problem to re-occur and execute the host command.

Re the other questions: the IP address is fixed, manually entered. /etc/resolv.conf contains the IP addresses of the two DNS servers that I normally use.