Syed Khairuddin

What are Single Label Domain Names or (SLD)

I have seen lot of folks on the technet forums asking about Single Label Domains and I thought it would be a nice idea to take some time and write about it.

What are single label domains ??

DNS names that do not contains suffix such as .org, .net, .com etc are considered as Single Label DNS names, for an example lets say that I have an Active Directory Domain with a name VIRMANSEC with out .com then its considered as Single Label Domain.

Microsoft does not recommend to use domains that have single-label DNS names. If you do create single-label DNS names, you may have the following issues.

• Some server-based applications are incompatible with single-label domain names like

1. Microsoft Exchange 2000 Server
2. Microsoft Exchange Server 2007
3. Microsoft Internet Security and Acceleration (ISA) Server 2004
4. Microsoft Live Communications Server 2005
5. Microsoft Operations Manager 2005
6. Microsoft SharePoint Portal Server 2003
7. Microsoft Systems Management Server (SMS) 2003
8. Microsoft Office Communications Server 2007

• Client computers and domain controllers that are joined to single-label domains require additional configuration to dynamically register DNS records in single-label DNS zones.

• Client computers and domain controllers may require additional configuration to resolve DNS queries in single-label DNS zones

• Transitioning from a single-label DNS domain name to a fully qualified DNS name is non-trivial and consists of two options either perform a migration using ADMT tool or Rename the Domain using Domain rename tool.

I hope by reading the above content you have gathered a good understanding about single labeled domains.