Redirect internal HTTP Requests

Firstly my apologies if this is the wrong place to be posting this question.

I have a web application that is setup on a sub-domain. The sub-domain has an A record pointing to the IP address of the network of the company that the application is being used by. This works just fine, you type in the subdomain and it goes to the webserver on their network.

This works perfectly, but only if you are outside the network. If you are in their office on the network that the server is on then when you request the sub-domain you get sent to the router's web-based configuration. One solution to this is simply to use the internal IP address of the webserver, but there are many references to the domain from within the web application, so none of the links etc... work.

The router is a SpeedTouch 780. The webserver is a QNAP TS-109. I have full control over the DNS for domain.

Any help/suggestions welcome!

Many thanks in advance.

Sorry if I misunderstand your question. Could you setup an internal DNS server for your LAN? Then create a forward lookup zone for whatever.mysite.com and an associated A record for the resource?

For instance, let's say that your local domain is mycompany.local. Your mail record is obviously for mycompany.com. On your local DNS servers you could create a forward lookup zone for mycompany.com and point mail.mycompany.com to your internal host.

The local network is not setup with a domain, it is just a microsoft workgroup.

Would you suggestion still work in this case?

Basically the main domain, lets say xyz.com is hosted on an external server, and there is an A record for admin.xyz.com that points to the IP address of the companies' network, this all works fine for external HTTP requests to admin.xyz.com, since the router forwards the ports correctly to the webserver, however any internal requests obviously don't go through the port forwarding in the router, so any internal HTTP requests go to the router configuration page.

So yes, what I need is something that will translate admin.xyz.com into the internal ip address of the webserver. Which I suppose is what an internal DNS server would do?

There are 2 windows 2000 servers running on the network, could I set one of these up to do the job? If so could you point me to some kind of tutorial that might help me in the right direction to acheive what I'm after?

many thanks again for your help!

I'm pretty sure that you could use one of the servers to get it to work. You may have to play with port bindings on the site or something (not sure though) if it's not using a default port.

Take a look here and see if that helps.

Yes. Internet "domains" are just DNS zones and they have nothing to do with Windows or Active Directory (except that a windows domain can/should also have a zone of the same name). In fact, you can configure your DHCP server to cause all the machines that use it to add the yourdomain.com suffix to their machine names so they could address each other as machineName.yourdomain.com or just machineName.

Are you running WINS on one of your servers?

If you're going to setup internal DNS, you should have two of them so the whole network doesn't go south every time you reboot one of the servers. DNS on Windows servers is very stable, but you are probably using those servers for stuff that might not be so solid. It's very simple to setup.

Microsoft has some documentation on how to setup DNS servers.