Part 3: Configuring the DNS Server to Pass DNS Requests to the Internet
When you setup a Windows DNS server by default, it thinks it is the DNS server and that no others exist. Let’s say you have a basic hub or switch with three clients and the server connected to the switch. DNS resolution will work great within the domain, but what if the clients want to get to the Internet? Well, first you would need a physical Internet connection to the hub/switch. Then, you would need to configure the IP address of the ISP’s DNS server within each client’s TCP/IP Properties page. Or… you could configure the domain’s DNS server to forward client Internet requests to that external DNS server that exists on the Internet. Let’s show how to do this now.
- First, you will need to know the IP address of the external DNS server you want to forward to. This can be found by romming into your router, or by calling your ISP.
- Within the DNS snap-in, highlight the actual server name, for example 2003DC. It is located directly under where it says DNS.
- Right-click the server and select Properties.
- Click the Forwarders tab.
- In the Selected Domain’s Forwarder IP Address list, type the IP address of the external DNS server, as shown in Figure 3. Then click Add. If there is more than one DNS server used by the ISP (common), add the additional IP addresses as well.
- Click OK to save.
Figure 3 Adding a forwarder IP.
At this point, when a client tries to go to a webpage on the Internet, the DNS request will first go to the local DNS server, and then will be forwarded to the Internet. It’s a lot easier than changing the Preferred DNS server IP address on every client! It might also be possible to forward to the router depending on the type of router used. And of course, it is also possible to connect the local DNS server directly to the Internet (making it part of the Internet). However, this requires some doing, and I recommend placing that DNS server on a DMZ.