Windows 7 / Networking

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Configure Single-Label DNS Resolution

The vast majority of networks use DNS as the primary name resolution system, but there are alternatives. For example, for many years Windows Internet Name Service (WINS) was used as an alternative, and in many networks it still is in use. Unfortunately, as you move forward to the next version of TCP/IP, which is called IPV6, there is no support for WINS. You will need another way to resolve single-label host names besides WINS. If there is no WINS, a DNS client can still resolve a single-label name by appending a dns suffix to the name and trying to find it in DNS.

If you are planning on using IPV6, all name resolution will go through DNS. If you still have single-label names in your network, Windows Server 2008 R2 uses a special zone called a global names zone (GNZ) to house these records and facilitate the resolution of those names through DNS. GNZ is not a replacement for WINS; instead, it provides an avenue for name resolution while you transition WINS out of your network. The GNZ is created and managed much the same as a standard primary zone. You should not enable dynamic updates for the GNZ to prevent its resource records from being registered into the zone.

Creating the GNZ

The process of creating the GNZ begins with DNS Manager:

1. Open DNS Manager.
2. Right-click the name of the server.
3. Choose New Zone.
4. Click Next in the Welcome To The New Zone Wizard.
5. Select the Primary Zone type, make sure the Store In Active Directory check box is selected, and click Next.
6. Select All DNS servers running on Domain Controllers in this forest.
7. Click Next.
8. Click Forward Lookup Zone.
9. Click Next.
10. Type GlobalNames in the Zone Name box, and click Next.
11. Select Do Not Allow Dynamic Updates, and click Next.
12. Click Finish.

It is also possible to enable GNZ from the command line using the dnscmd tool and the following command:

DNSCMD /config /enableglobalnamesupport 1

Either method will work to enable GNZ, and in both cases you will still need to configure the appropriate records for the zone.

After the forward lookup GNZ has been created, you will need to add the alias resource records (called the CNAME), for each of the single-label clients in the network. This can prove to be a daunting task if you have lots of single-label clients and may provide the motivation necessary to quickly upgrade them to traditional DNS clients. To add new CNAME records for the single-label clients, follow these steps:

1. Open DNS Manager.
2. Locate the GNZ.
3. Right-click the zone, and choose New Alias (CNAME).
4. Type in the alias name.
5. Type in the fully qualified domain name.
6. Click OK.