Installing RRAS Disables 128-bit RAS Encryption

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This article was previously published under Q174474

SYMPTOMS

When you dial into your Microsoft Windows NT Routing and Remote Access Service (RRAS) Server, you may receive one of the following error messages depending on the Remote Access Service (RAS) client that you are using:

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Windows 95 using Dial-Up Networking 1.2

Error 720: Dial-Up Networking could not negotiate a compatible set of network protocols you specified in the Server Type settings. Check your network configuration in the Control Panel then try the connection again.

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Windows NT Server or Workstation (Service Pack 1 or 2, or no Service Pack)

If Require Data Encryption is Enabled:

Error 742: The remote computer does not support the required encryption type.

If Any Other RAS Security Setting is Enabled:

TCP/IP CP reported error 733: The PPP control protocol for this network protocol is not available on the server.

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Windows NT Server or Workstation (Service Pack 3)

If Any RAS Security Setting is Enabled:

TCP/IP CP reported error 733: The PPP control protocol for this network protocol is not available on the server.

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Windows NT Server with RRAS Update

If Require Strong Data Encryption is Enabled:

Error 741: The local computer does not support the required encryption type.

If Any Other RAS Security Setting is Enabled:

TCP/IP CP reported error 733: The PPP control protocol for this network protocol is not available on the server.

In addition to one of the above RAS client errors, your RRAS server will log the following event log error in Event Viewer:

Event ID : 20073
Source : Router
Description: The following error occurred in the %protocol_name% module on port %port_name%. The local computer does not support the required encryption type.

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CAUSE

Your RRAS server has been configured for 128-bit RAS Encryption, however Ndiswan.sys has been replaced with the 40-bit version of the file.

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RESOLUTION

To resolve this issue, follow the steps in the following article in the Microsoft Knowledge Base:

169895 (http://support.microsoft.com/kb/169895/EN-US/ ) Enabling 128-bit Encryption for Routing and Remote Access

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MORE INFORMATION

When you install Routing and Remote Access Service on top of Service Pack 3 (40-bit or 128-bit), it, by default, replaces Ndiswan.sys with a 40-bit version.

If a RAS or PPTP connection is successful using 128-bit encryption, the following event will be logged in Event Viewer on your RRAS Server:

Event ID : 20142
Source : Router
Description: The user <username> has been connected and has been successfully authenticated on port <port_name>. Data sent and received over the link is strongly encrypted.

For additional information, please see the following articles in the Microsoft Knowledge Base:

104292 (http://support.microsoft.com/kb/104292/EN-US/ ) Identifying 128-bit Windows 95 DUN Client

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