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Windows 11 upgrade vs build - EAP timeout

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  • 1.  Windows 11 upgrade vs build - EAP timeout

    Posted Aug 22, 2025 09:26 AM

    Has anyone had this one yet?  We're moving to WIndows 11 so we upgraded a few test machines and they worked with Clearpass/OnGuard with no problems.  We recently bought hundreds of new laptops to replace non-Win11 compliant ones and we have found that a bare metal build of Win11 does NOT work with Clearpass.  We are getting error 9002, RADIUS authentication is timing out, client did not complete EAP transaction.

    There is some difference between a fresh build machine and an upgraded Win11 machine and so far we've not found it.  We're doing machine authentication against AD and have a GPO which pushes out the necessary certificates and turns on DOT1x wired & wireless services.  We've checked the TLS versions and they appear the same.  We thought it might be credential guard but it's disabled on both built and upgraded versions. 

    Authentication methods in the services section of Clearpass are set to EAP-TLS first then EAP-PEAP.  We're running v6.12.5 and having no issues with anything else at the moment.  Client logs on the machine shot it seeing EAP requests but not much else we can make sense of.  Our server guys are looking at it now to try and figure out what might be different.  Any suggestions?



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  • 2.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Aug 22, 2025 09:34 AM

    Share the exact alert text from an attempt for better clarity, but a time out like that is almost always going to be a certificate trust issue.  Either client isn't trusting the RADIUS cert or the client is never receiving the RADIUS cert packets.  Also, make sure that the new machines have up to date drivers for the network adapters.



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    Carson Hulcher, ACEX#110
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  • 3.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Aug 22, 2025 10:04 AM

    Hi Carson.  Attached is the exact error.

    clearpass radius error
    The service desk people say the logs on the client show it did receive an EAP request but I've not got more detail on the exact wording of it.  I'll try and get that.  They did check the certs and services were there and could see no issues with the setup in cert manager.  It's installed and set up via the same global policy which installs them on the non Win11 and 'upgraded Win 11' machines which work just fine.
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  • 4.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Aug 22, 2025 10:14 AM

    Likely easiest to troubleshoot this with packet captures.  Grab one at the client, see if RADIUS is sending the certificates over to the client.

    Last time I saw this there was an MTU issue and had to set the proper EAP fragment values on the NAD.



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    Carson Hulcher, ACEX#110
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  • 5.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Aug 22, 2025 10:36 AM

    I did a search before posting and did find mention of changing MTU size.  By NAD I'm assuming you mean on the PC or laptop affected?

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  • 6.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Aug 22, 2025 10:39 AM

    NAD is the switch, or if wireless the AP/controller/gateway



    ------------------------------
    Best Regards
    Jonas Hammarbäck
    MVP Guru, ACEX, ACDX #1600, ACCX #1335, ACX-Network Security
    Aranya AB
    If you find my answer useful, consider giving kudos and/or mark as solution
    ------------------------------



  • 7.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Aug 22, 2025 10:34 AM

    Microsoft has changed the way Windows require information in the 802.1x profile.

    You should enable the certificate validation and also provide the host name(s) found in the ClearPass certificate(s). Also select the issuer root of the ClearPass certificate.

    This will suppress the prompt to the user. If you have an older version of the GPO you may have a setting to not prompt the user for new certificates, and if the client can't validate the certificate based on the information in the GPO and are not able to prompt the user, it will not be able to connect.

    Can you take a screenshot of your GPO settings?



    ------------------------------
    Best Regards
    Jonas Hammarbäck
    MVP Guru, ACEX, ACDX #1600, ACCX #1335, ACX-Network Security
    Aranya AB
    If you find my answer useful, consider giving kudos and/or mark as solution
    ------------------------------



  • 8.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Aug 25, 2025 07:02 AM

    I'm not an admin for the server environment.  I'll pass the info on to the guys and see if I can get a snapshot of what we've got currently.  We're also going to alter the MTU size down slightly after a bit of testing to see if that helps the issue.

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  • 9.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Sep 01, 2025 08:58 AM
      |   view attached

    Hi all.  I've attached packet captures showing me plugging a Win11 fresh build laptop into the network.  It seems to show the EAP request in PEAP first, the laptop responding, then the request switches to EAP-TLS instead.  Finally it looks like PEAP again and then assigns it a 192.168.8.X address as it kicks it over to the visitors VLAN for failing to authenticate.

    I'll see if I can borrow one of the laptops that upgraded accidentally from Win10 to Win11 since they work fine for whatever reason.  We can't see anything obviously different in the services or certs but maybe a capture of that transaction will provide a hint.

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    Attachment(s)

    zip
    Win11 EAP captures.zip   263 KB 1 version


  • 10.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Sep 05, 2025 06:55 AM

    Hi all.  We seem to have tracked down the issue to the new virtualisation security on Windows 11 stopping MSCHAPv2 authenticating properly.  Disabling that security gets it to work.  We would obviously prefer to get EAP-TLS working on Clearpass rather than put out policies to disable Windows security features.  Currently Clearpass is set to try EAP-TLS first then fail over to EAP-PEAP.

    From the packet captures it looks like the Clearpass server is trying to use TLSv1.3 and our Win11 build only has v1.2 and the negotiations fail.  The only control over TLS version I can find is in the server cluster config page.  I can set TLSv1.3 support to All, None, Admin or Network.  Same for v1.0 and v1.1.  If I want to set TLS on the server to 1.2 only I take it I have to set that parameter to 'none'?  I'm wary of trying it without advice since it's a cluster wide change on a live environment with 2000 users and I'm clueless.

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  • 11.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Sep 08, 2025 09:45 AM

    If you set that field to "Admin", then the only usage for TLS 1.3 will be HTTPS rather than EAP.



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    Carson Hulcher, ACEX#110
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  • 12.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Sep 09, 2025 05:53 AM

    My guess is that you try to connect to the SSID/wired 802.1X without configuration on the client side.

    You should pre-configure your client/supplicant, and then you can fix it to EAP-TLS only (or maybe better TEAP) and proper server validation. Then the client doesn't need to guess, and won't connect to something else or ask for username/password.

    Configuration of you clients normally happens through Group Policies, or Intune/MDM.



    ------------------------------
    Herman Robers
    ------------------------
    If you have urgent issues, always contact your HPE Aruba Networking partner, distributor, or Aruba TAC Support. Check https://www.arubanetworks.com/support-services/contact-support/ for how to contact HPE Aruba Networking TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or HPE Aruba Networking.

    In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
    ------------------------------



  • 13.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Sep 09, 2025 06:02 AM

    Hi Herman.  We use a group policy to turn on the wired & wireless dot1x services, install the certificates and set up the SSID which is not broadcast.  Our server people have been running tests using an upgraded build and a fresh build Windows 11 and have found that the problem is MSCHAP.  It appears TLS doesn't work so it tries EAP-PEAP next and fails because of MSCHAPv2 being broken by the new Credential Guard system on Win11.  We can get the authentication working again by disabling it but I'd prefer to get EAP-TLS or TEAP working instead.

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  • 14.  RE: Windows 11 upgrade vs build - EAP timeout

    Posted Sep 11, 2025 09:55 AM

    Hidden SSIDs are a bad idea, and these are known to give stability and roaming issues (and doesn't provide too much privacy/security). I'm not sure if what you see is part of it, but it's probably easy to temporarily enable the SSID broadcast and see if that changes the behavior.

    Does it work if you manually configure the client? In that case, you may export as XML and create a GPO based on XML import SSID definitions and see if that works better.



    ------------------------------
    Herman Robers
    ------------------------
    If you have urgent issues, always contact your HPE Aruba Networking partner, distributor, or Aruba TAC Support. Check https://www.arubanetworks.com/support-services/contact-support/ for how to contact HPE Aruba Networking TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or HPE Aruba Networking.

    In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
    ------------------------------