Windows 2003 Server DNS Local Resolution Problem

I am running Windows 2003 Small Business on a small network.

It is properly configured and the DNS is working properly with my local ISP's DNS servers entered for forwarding.

However I have a minor problem I host my own e-mail and web servers and and the Windows 2003 DNS server intermittently seems unable to resolve the local servers' IP addresses.

The e-mail server's local IP address is 192.168.1.103 (which is also the DNS server) and the webserver's IP is 192.168.1.100.

If I try to access for example my e-mail server at http://webmail.domain.com it sometimes may come back as not available. On the other hand if I contact it directly at it's local IP address http://192.168.1.103 it will come up. Then if I request it from its domain name again it will load fine.

I can access the pages fine from outside the network which leads me to believe that its local resolution problem.

Thanks for any help you can offer.

 

You can create a new zone on your local DNS for domain.com (replace domain.com with your external namespace). Then create A records for the resources you want to be able to access from within your network.

So in your example, you would add a zone of "domain.com" and then add to that an A record for "webmail" with an IP address of 192.168.1.100.

The key point is that as soon as you do this, you need to add ALL the resources that you need to access in this name space, to the new zone. Your DNS server will be the master for this name space as far as local machines are concerned and you won't be able to access domain.com addresses from your local network unless they are defined within the new zone.

Therefore if you have a hosted website (for example www.domain.com) you will have to put in an A record for that too (in this example, an A record for a host 'www') with the public IP address for the host.

The beauty of this solution is that you can use webmail.domain.com internally and externally without reconfiguration. Connect internally, and your local DNS will resolve the IP address to the local one. Connect externally and you ISP's DNS will resolve the IP address as the public one.

 

Thanks for the thorough explanation.

I finally understand how to do this now.

 

Splendid result then!