Occasional Contributor II

802.1x Certificate issues

I am facing an issue while authenticating AD users via aruba controller.iI am facing following error

Certificate error.png

Error No on NPS Eventviewer is 6237 with reason 16





Guru Elite

Re: 802.1x Certificate issues

That is a normal part of connecting doe the first time. Simply click Connect.

Sent from Nine

| Tim Cappalli | Aruba Security | @timcappalli | |

NOTE: Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba or Hewlett Packard Enterprise.

Re: 802.1x Certificate issues

For 802.1x authentication you need an SSL Server certificate on your RADIUS server; and that certificate must be trusted (and configured) by your client.


You should put the certificate on most cases on the RADIUS server, NPS in your case, however the controller can present a certificate to the client as well. This is called 'Termination' in your 802.1x Authentication profile. Your screenshot shows that the controller terminated the RADIUS connection with its built-in certificate. If you did setup your AD with a certificate, you may need to switch off Termination on the 802.1x authentication profile.


If you need to setup NPS, this post: may help in setting up NPS correctly.



If you have urgent issues, please contact your Aruba partner or Aruba TAC (click for contact details).
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