This article was previously published under Q214555
Microsoft Internet Authentication Server (RADIUS) can be used to authenticate remote dial-in users from another domain if the Radius server's domain trusts the user's domain.
To successfully authenticate users from a domain other than the RADIUS server's domain, the user name supplied should be in the form of domain\user and the Radius server's domain should trust the user's domain.
However, when you dial into a Routing and Remote Access server that is using a Radius server for authentication, cross-domain authentication may fail even when you specify the user name in the domain\user format.
To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update. For information on obtaining the latest service pack, please go to:
152734 how to obtain the latest windows nt 4.0 service pack
For information on obtaining the individual software update, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:
Microsoft has confirmed that this is a problem in Microsoft Routing and Remote Access Service Update for Windows NT Server 4.0. This problem was first corrected in Windows NT version 4.0 Service Pack 5.
When installing the hotfix using Service Pack or hotfix.exe or hfx.exe the following registry entries are added automatically. But, if applying the fix manually then the following registry changes need to be done manually:
Start Registry Editor (Regedt32.exe).WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
Locate the following key in the registry:
On the Edit menu, click Add Value, and then add the following registry value:
Value Name: DoNotStripDomainName Data Type: REG_DWORDValue: 1