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DHCP Reservation with Unique ID Different than MAC RRS feed

  • Question

  • Hello, I am trying to create a DHCP reservation using Windows Server 2012 R2 DHCP Server for systems that are connecting over a Cisco AnyConnect VPN.  The ASA VPN endpoint is configured as a dhcp relay.  The Unique ID that is generated by the ASA is not the MAC address, but is a long hex string that is a combination of the ASA MAC, FQDN of the client, and Connection Name.  The client does get a valid IP address when they connect. I can also make a reservation through powershell or by right clicking on the DHCP lease, but the reservation does not work.  If the client disconnects and reconnects, they are leased a completely different IP address and there are duplpicate entries with the same Unique ID listed. Is there any way to assign reservations using Windows DHCP Server using this odd Unique ID or make a reservation that uses the Computer Name?  Thank you in advance.  
    Friday, February 10, 2017 10:40 PM

All replies

  • Hi Eljasbo,

    >>Is there any way to assign reservations using Windows DHCP Server using this odd Unique ID or make a reservation that uses the Computer Name?

    No, client could only obtain IP address from DHCP reservation by MAC address.

    Please check link below for further understanding:

    Design Option 2: DHCP/BOOTP Reservations

    https://technet.microsoft.com/en-us/library/dd334714(v=ws.10).aspx

    Best Regards

    John


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    Tuesday, February 14, 2017 8:56 AM
  • Thank you for your response.   I will have to use a different product for dhcp then, as there is no unique mac address being sent with this configuration.  
    Tuesday, February 14, 2017 2:26 PM
  • Hi Eljasbo,

    If there is anything we can do for you, please feel free to post in the forum.

    Best Regards

    John


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Wednesday, February 15, 2017 9:29 AM
  • Hi Eljasbo,

    yes, you can enter that clientid in Windows DHCP!
    We have done it with DHCP W2K8R2.
    DHCP Management Console gives a hint "The Unique client Identifier is not valid", but it works!
    Client gets IP-Address.

    I don't know if Microsoft knows this!

    Best regards

    Tuesday, April 24, 2018 8:18 AM