I have been looking through the information here, and I am not seeing anything that would can change to the switch configuration . Everything works fine until we add the Windows RADIUS into the mix. With the Wireshark you are even seeing the request make it to the server, but then the server never sent a packet back to authenticate the user and the switch timed out for authentication and logged it as rejected.
Hello from France, One of my project for a customer is to create a secure authentification via 802.1X. I chose to use freeradius. But the customer didn't want to integrate a linux solution. So I switched to Microsoft Windows server 2008 R2 and the NPS. I set up two solutions First, a NAP. The solution works without any problems. But the second, configuring dell powerconnect  device to a authenticate via active active directory has not working. I found and tried many howtos on the web, but no one are compliant with my device. someone have to deploy this solution with the NAP  of Microsoft? Is there a POC from dell, which allow to solve it ?  Thank for your helps Théo
Pwerconnect 5448, Windows Server 2008 R2