DNS subdomains 'randomly' not accessible

[Martin Blank]

I have several customers who cannot access any subdomains, but the main domains load properly. However, this is not a universal problem. It seems to affect mostly RoadRunner customers, but there are some non-RR people who are also affected. Any suggestions at things I can look at?

Edit: The people affected by this can get to subdomains for some domains on the server, but have difficulty with certain domains.

[CMI]

We've had this problem too. I can say that at the very least they are aware of the problem and investigating.

[IWorx-Chris]

CMI, you just jogged my memory to the possible solution. Martin, are you using Sago's DNS servers by chance?

Chris

[Martin Blank]

No, I'm not. However, I seem to have more users with problems using Roadrunner than anything else, maybe half of them.

[Martin Blank]

Found the problem. It was a poor configuration on my part. Lack of entries for the ns1 and ns2 nameservers for the domain hosting the DNS, and a flawed SOA implementation.

Most DNS lookups worked fine because the servers were configured with lax settings. Those that required better verification failed lookups on all subdomains, and some base domains.