Article ID: 226487 - View products that this article applies to.
This article was previously published under Q226487
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When you apply Service Pack 5 to your computer running the Microsoft Internet Authentication Service (IAS), IAS does not return an Access_reject message when an invalid logon attempt is made.
Windows NT Server or Workstation 4.0A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that are experiencing this specific problem.
To resolve this problem, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:
http://support.microsoft.com/contactus/?ws=supportNote In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.
This hotfix corrects a problem in IAS Remote Authentication Dial-In User Service (RADIUS) server in which RADIUS does not respond to an invalid authentication request with an "access_reject" packet to the RADIUS client. This hotfix is not included in Service Pack 6 (SP6), or in the SP6 RADIUS Rollup fix located on the SP6 CD-ROM in the Support\IAS folder. For additional information, click the article number below to view the article in the Microsoft Knowledge Base:
194957You should apply the Rollup fix on the SP6 CD-ROM before installing this fix.
(https://support.microsoft.com/kb/194957/EN-US/ )IAS Vendor-Specific Attributes Do Not Work
The English-language version of this fix should have the following file attributes or later:
Date Time Version Size File name Platform ------------------------------------------------------------- 5/20/99 4:15pm 6.0.2723.0 9264 Authsam.dll x86 5/14/99 1:32am 4.00 24336 Rassapi.dll x86
Windows NT Server 4.0, Terminal Server EditionTo resolve this problem, obtain the latest service pack for Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/152734/EN-US/ )How to Obtain the Latest Windows NT 4.0 Service Pack
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows NT Server version 4.0, Terminal Server Edition Service Pack 6.
For additional information about IAS, RADIUS, and remote authentication, please see the following articles in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/197506/EN-US/ )IAS Incorrectly Validates User Accounts