(Problem) Event ID:20073 Attempting Radius Authentication on RRAS Server

ID: Q220954

The information in this article applies to:

Microsoft Windows NT Server version 4.0 SP4, used with:
- Microsoft Routing & Remote Access Service Update for Windows NT Server version 4.0

SYMPTOMS

When you dial into a computer running Windows NT Server and Routing and Remote Access Service (RRAS), the following error message may be displayed on your RAS client computer:

Error 629: You have been disconnected from the computer you dialed.

Additionally, the following error is logged in the Event Viewer of the Windows NT 4.0 RRAS server (after every attempted incoming call):

Event ID: 20073
Source: Router
Type: Error
Description: The following error occurred in the Point to Point Protocol module on port %port%. There are no authentication protocols available for use.

Incoming calls to the Windows NT RRAS server are not able to connect.

CAUSE

This problem occurs because your Windows NT RRAS server's authentication and encryption settings are set to require Microsoft encrypted authentication and you are using RADIUS as your authentication provider.

RESOLUTION

To resolve this problem, perform one of the following:

Set Authentication and Encryption settings to Require encrypted authentication or Allow any authentication including clear text.

Leave Authentication and Encryption settings set to Require Microsoft encrypted authentication and set OfferMSCHAP to 1 in the registry. For more information, please see the following Microsoft Knowledge Base article:
Q219283 How to enable MS-CHAP with Radius authentication

STATUS

Microsoft has confirmed this to be a problem in Microsoft Windows NT Server version 4.0 with Routing and Remote Access Update.

Additional query words:


Keywords          : ntras 
Version           : winnt:4.0,4.0 SP4
Platform          : winnt 
Issue type        : kbprb

Last Reviewed: June 30, 1999