Hi All,

I appear to have a problem with my DNS.

It started today when all of a sudden the GWIA seemed to be having issues sending out being unable to locate any MX records for any recipients and started giving errors such as 450 (host down) and then started saying error 450, host down (mydomain.com) - mydomain.com being our actual domain.

So after a bit of investigation, I recreated the record for our domain and gave it the IP of our DNS server ( as it was pointing to the external mail address before for some reason???

So at the moment, our @ record is as an A record, and has another NS record in it as srvmanage.mydomain.com

After doing this, mail started working again, faster than before (always a plus).

Then not long after I made this change, we can no longer get to the web interfaces for a number of servers using their DNS entry. I can ping none of my DNS entries and any of our DNS entries that are also available externally such as mail and webmail are resolving to their external addresses, which they shouldn't be doing inside our network.

Have I inadvertantly stuffed DNS? If I try and do an nslookup I get the following:

*** Can't find server name for address w.x.y.z: Non-existent domain

But I have the PTR records there set up from before. Nothing has changed with them.

I also get a non-authoritative answer from my nslookup, which I have to assume is coming from our ISPs DNS server as I am getting the external IP address of things like mail.mydomain.com

Any help appreciated.