NPS radius clients not authenticating

dirkdigs 906 Reputation points

we have setup NPS on server 2019.
The radius clients have been added and the shared secret has been set. i have verified the network connectivity between the clients and the server in both directions. I can see TCP port 1812 requests coming in from the clients (access points) the user authentication test is failing

I did find this
Reason: Authentication failed due to an EAP session timeout; the EAP session with the access client was incomplete.

How can i troubleshoot this?

How to resolve this?

Windows Server Infrastructure
Windows Server Infrastructure
Windows Server: A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.Infrastructure: A Microsoft solution area focused on providing organizations with a cloud solution that supports their real-world needs and meets evolving regulatory requirements.
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  1. Candy Luo 12,496 Reputation points

    Hi ,

    According to the error message, it is always caused by EAP payload size is large.

    You can lower the EAP payload size by configuring the Framed-MTU attribute in network policy settings properties in the NPS console. See if this can solve the problem.

    For your reference:

    Authentication Failed Due To An EAP Session Timeout; The EAP Session With The Access Client Was Incomplete.

    Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

    Best Regards,



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