When you try to locate a service on the server that is running Microsoft Windows Small Business Server 2003 from a client computer on the local area network, you may receive the following error message: At the bottom of the error message, you may see the following information: This problem may occur after you configure Windows Small Business Server 2003 to permit a connection from the Internet through a router device.

This problem may occur if both of the following conditions are true:

• Windows Small Business Server has only one network adapter and is configured behind a router device.
• A client computer tries to access the server by specifying the externally accessible fully qualified domain name (FQDN).

Note Typically, users on the local area network do not use the external domain name of the server. However, Microsoft Outlook Mobile Access (OMA) users require access to the external domain name of the server to synchronize OMA devices. This problem occurs only with certain models and certain firmware revisions of router devices. For additional information about the devices that this problem is known to occur with, see the "More Information" section of this article.

To work around this problem, configure the internal client computers to resolve the external FQDN of the Windows Small Business Server-based server to the internal IP address of that server. To do this, create a new Domain Name Services (DNS) zone for the external FQDN of the server.

To create a new DNS zone, follow these steps:

1. Click Start, point to Administrative Tools, and then click DNS.
2. Expand your server, right-click Forward Lookup Zones, and then click New Zone.
3. In the New Zone Wizard, click Next, leave the Primary zone option selected, and then click Next.
4. Click the replication option that you want, and then click Next.
5. In the Zone name box, type the external FQDN that your internal client computers require access to. For example, type www.example.com.
6. Click Next.
7. Leave the Allow only secure dynamic updates (recommended for Active Directory) option selected, click Next, and then click Finish.
8. Expand Forward Lookup Zones, expand the new zone that you created, right-click the new zone that you created, and then click New Host (A).
9. Leave the Name box blank, and then type the internal IP address of the Windows Small Business Server-based server in the IP address box.
10. Click to select the Create associated pointer (PTR) record check box, and then click Add Host.
11. When you receive a message that states that the host record www.example.com was successfully created, click OK.
12. Click Done, and then exit DNS.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section of this article.

This problem occurs with certain router devices and is also known as a "loopback support" problem. This problem occurs with the following router devices:

• Microsoft Wireless Base Station MN-500
• Microsoft Wired Base Station MN-100
• D-Link Broadband VPN Router DI-804
• 3Com OfficeConnect Cable/DSL Gateway 3C855

This problem may be resolved by a firmware update for these devices. Contact your hardware vendor to inquire about a device firmware update that fixes the loopback support problem. For information about how to contact computer hardware manufacturers, click the appropriate article number in the following list to view the article in the Microsoft Knowledge Base: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information. The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.