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NPS server with NPS extension for MFA RRS feed

  • Question

  • Hi,

    I've setup NPS server with NPS extension for MFA to be used in order to use 2-factor authentication for clients VPN requests. 

    Most of the clients connects fine but with some of them they get authentication failures several times until several reboots and at the and connecting successfully. 

    What I can see in security logs on the NPS server are usually two different audit failure logs in different cases:

    1) Event ID: 6273; Reason code: 21; Reason: An NPS extension dynamic link library (DLL) that is installed on the NPS server rejected the connection request.

    2)  Event ID: 6274; Reason code: 9; Reason: The request was discarded by a third-party extension DLL file.

    What could be the reason for these events and how to prevent them? As I said, at last users can establish VPN connection but before that maybe they are presented with several authentication failures or performed several reboots to try if that can fix things.

    Kind regards,

    Zoran


    Zoran Zasovski

    Monday, November 27, 2017 5:11 PM

All replies

  • Hi,

    Event ID 6274 — NPS Accounting Request Message Processing
    Reconfigure, upgrade, or replace the RADIUS client
    This condition occurs when NPS discards accounting requests because the structure of the accounting request message that was sent by a RADIUS client does not comply with the RADIUS protocol.
    To reconfigure, upgrade, or replace the RADIUS client:
    1 Contact your RADIUS client vendor for configuration assistance or firmware updates. Many RADIUS client vendors provide updated firmware that allows the RADIUS client to send Accounting-Request messages that comply with the RADIUS protocol.
    2 If your RADIUS client vendor cannot provide reconfiguration instructions or firmware that allows the RADIUS client to send RADIUS protocol-compliant messages, you must obtain and install a RADIUS protocol-compliant RADIUS client for use with NPS.

    Event ID 6273 — NPS Authentication Status
    This error might be caused by one of the following conditions:
    1 The user does not have valid credentials
    2 The connection method is not allowed by network policy
    3 The network access server is under attack
    4 NPS does not have access to the user account database on the domain controller
    5 NPS log files or the SQL Server database are not available

    More information about Event,  please refer to the following article:

    https://technet.microsoft.com/en-us/library/cc735399%28v=ws.10%29.aspx?f=255&MSPPError=-2147217396

    https://technet.microsoft.com/en-us/library/cc735339(v=ws.10).aspx

    Best Regards,

    Frank


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    Tuesday, November 28, 2017 9:23 AM

  • Hi,
    Just checking in to see if the information provided was helpful. Please let us know if you would like further assistance.

    Best Regards,

    Frank

    Please remember to mark the replies as answers if they help and unmark them if they provide no help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Friday, December 1, 2017 10:20 AM
  • Uninstall the NPS Extension For Azure MFA, (which will break the NPS Extension for Azure MFA obviously).
    Wednesday, March 20, 2019 2:42 PM