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  • 1.  How to handle multiple CAs for one SSID during a CA migration

    Posted Oct 04, 2025 07:11 AM

    Hey all,

    My team is encountering a situation where we are migrating from an onsite Certificate Authority (CA A) that will be retired to a cloud Certificate Authority (CA B) that will replace it.

    Our goal is to support all of our clients under one SSID. We utilize EAP TLS as our authentication method.

    During this transition, there will be client devices that are of various levels of configurability with many being older and only able to support certificates issued by either CA A or CA B but not both.

    We are encountering a reality where a service rule can only support one service certificate issued by either CA A or CA B, but not both. 

    Our challenge is finding a way to supporting both CAs with the same SSID for authentication. We are finding it challenging to find criteria that would distinguish devices by what certificate they present since the Server Certificate is presented first in the EAP transaction before the Client Certificate and our clients are very diverse in nature and eventually will all be on CA B. 

    Does anybody have advice on how to handle multiple CAs in an environment undergoing a rolling migration between CAs?

    Summary:

    • Environment: Wireless using EAP-TLS
    • Goal: One SSID
    • Clients can only have one CA at a time
    • Need to migrate from CA A to CA B, and clients are already starting to use CA B.

    Thank you!



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  • 2.  RE: How to handle multiple CAs for one SSID during a CA migration

    Posted Oct 04, 2025 07:32 PM

    you should be able to do that with ClearPass as the authentication server



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  • 3.  RE: How to handle multiple CAs for one SSID during a CA migration

    Posted Oct 07, 2025 10:44 AM

    Hello,

    We are using ClearPass 6.9.13 as our authentication server today. 

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  • 4.  RE: How to handle multiple CAs for one SSID during a CA migration

    Posted Oct 06, 2025 05:20 AM

    You need to have a NAC (Network Access Controller) in place to differentiate access logic. As @ariyap mentioned, you can do this using Clearpass.



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    Shpat | ACEP | ACMP | ACCP | ACDP
    Just an Aruba enthusiast and contributor by cases
    If you find my comment helpful, KUDOS are appreciated.
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  • 5.  RE: How to handle multiple CAs for one SSID during a CA migration

    Posted Oct 07, 2025 10:45 AM

    We are using ClearPass today.

    How would we use it to differentiate the logic needed between certificates being presented when the client certificate is being presented after the server certificate? Our devices are dumber in nature where they can't support sending different certificates based on what ClearPass provides, so we need to have a way to distinguish up front.

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  • 6.  RE: How to handle multiple CAs for one SSID during a CA migration

    Posted Oct 07, 2025 11:00 AM

    You can't differentiate on the certificate as the certificate isn't presented until after service categorization.  You must uniquely categorize the device into the proper service so that the correct service certificate is used.  The usual and easiest way to do this from the username (either in whole or in part) but you should be able to use any of the RADIUS attributes that show in the Access Tracker.

    If the client device can only support a single trusted root for the presented RADIUS certificate, then you may have to accomplish your goal in multiple steps or require manual intervention.  The "normal" answer for this situation would be to add the new CA to the trust list on the client device and then just issue a new RADIUS certificate from the new CA.



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    Carson Hulcher, ACEX#110
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  • 7.  RE: How to handle multiple CAs for one SSID during a CA migration

    Posted Oct 14, 2025 10:53 AM

    You probably don't need to have different services. If you keep the same server certificate on the ClearPass EAP service, by adding both Client CAs in the ClearPass Trust List, you can authenticate clients from either client CA. In you policy you CAN check which is the issuing CA and return a different role policy, but in most transitions you don't want that except maybe close to the end find clients that are still using the old certificates.

    For EAP-TLS, you don't need the server certificate to be from the same CA/PKI as the client certificate. Client must trust the root of the server certificate, Server/ClearPass needs to trust the client certificate by having it added to the Trust List with purpose EAP and enabled.

    Changing the server certificate to one issued by a new RootCA is much harder than changing the client CA.



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    Herman Robers
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    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.
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  • 8.  RE: How to handle multiple CAs for one SSID during a CA migration

    Posted Oct 06, 2025 04:01 PM

    This is entirely dependent on what RADIUS server you are using, has nothing to do with the WLAN environment.  Your best bet is going to be checking with the vendor for that RADIUS server.



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    Carson Hulcher, ACEX#110
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