Radius Client Uses 100 Percent CPU on Invalid Response

ID: Q186905

The information in this article applies to:

Microsoft Windows NT Server version 4.0 SP3
Microsoft Routing & Remote Access Service Update for Windows NT Server version 4.0
Microsoft Windows NT Server version 4.0, Terminal Server Edition

SYMPTOMS

When you use the Routing and Remote Access Service (RRAS) update with Radius authentication and accounting, the MPROUTER process consumes 100 percent processor time.

CAUSE

The Radius server returned an invalid length field in a response packet.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

Apply the Routing and Remote Access Hotfix Pack 3.0. For your convenience, the English version of this post-SP3 hotfix has been posted to the following Internet location. However, Microsoft recommends that you install Windows NT 4.0 Service Pack 4 to correct this problem.

ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/nt40/hotfixes-postSP3/rras30-fix/

For additional information about the Routing and Remote Access Hotfix Pack 3.0, see the following article in the Microsoft Knowledge Base:

ARTICLE-ID: Q189594
TITLE : RRAS Upgrade for WinNT Server 4.0 Hotfix Pack 3.0 Release Notes

STATUS

Microsoft has confirmed this to be a problem in Routing and Remote Access Update for Windows NT version 4.0. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.

Additional query words: tight loop

Keywords : NT4SP4Fix ntras kbbug4.00 kbfix4.00.sp4
Version : WinNT:4.0
Platform : winnt
Issue type : kbbug