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HYPER VISOR MAC USAGE RRS feed

  • Question

  • Good afternoon.  I am in the process of creating a Microsoft Server 2016 VM with Hyper Visor.  I came across some guidance from the following link:  https://solution-soft.com/sites/default/files/wysiwyg/Configuring%20Microsoft%20Hyper-V%20Virtual%20Machines%20to%20use%20a%20Static%20MAC%20address.pdf

    which states,

    NOTE: Microsoft Virtual Machines static MAC addresses must be within the following range:              

    Minimum Mac Address = 00-15-5d-01-80-00              

    Maximum Mac Address = 00-15-5d-01-8F-FF

    So, must I? 

    The reason I ask is that we are converting a physical server into a VM and retiring that physical server.  One of the programs on that server has licenses that are tied to that server's MAC.  I'd like to reuse that MAC.  As long as we avoid network collisions on our small network (about 20 physical and virtual machines) which is a closed loop system (i.e. not connected to the internet), I don't understand the above must statement.

    Monday, November 4, 2019 8:51 PM

All replies

  • Hi,

    Thank you for posting in forum!

    A MAC address has two parts to it, the OEM identifier and the unique value. To provide MAC addresses, Microsoft had to register to obtain its own identifier (00-15-5d), so all Hyper-V MAC address ranges start with these three octets. The remaining three octets are generated by using the last two octets of the IP address of the first enumerated NIC in the Hyper-V host, converted to hexadecimal. So if the IP address of the first enumerated NIC was 192.168.1.133, the last two octets are converted to hexadecimal 1.133 becomes 01-85 and used as the next two octets in the MAC address.  This gives 00-15-5d-01-85 as the first five octets. To set the range of 256 addresses, the last octet of the MinimumMacAddress is set to 00 and the last octet of the MaximumMacAddress is set to FF. This sets the MAC address pool range from 00-15-5d-01-85-00 to 00-15-5d-01-85-FF.

    For more information, please refer to: http://techgenix.com/mac-address-pool-duplication-hyper-v/

    Hope this can help you. Please let us know if you would like further assistance.

    Best Regards,

    Lily Yang


    Please remember to mark the replies as answers if they help.
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    Tuesday, November 5, 2019 6:39 AM
  • I acknowledge that Hypervisor has a set of reserved octals it uses.  I have the ability to statically set the MAC address when setting up the virtual server.  Must I used the first three octals of 00-15-5d which hypervisor populates?  Or, can I set the full MAC to whatever I want?
    Tuesday, November 5, 2019 1:39 PM
  • Have you contacted the owner of the application?  First to validate that it runs and is supported in a virtual environment.  Secondly how they suggest (support) changing the MAC address for the application.

    tim

    Tuesday, November 5, 2019 2:18 PM
  • Good afternoon.  I am in the process of creating a Microsoft Server 2016 VM with Hyper Visor.  I came across some guidance from the following link:  https://solution-soft.com/sites/default/files/wysiwyg/Configuring%20Microsoft%20Hyper-V%20Virtual%20Machines%20to%20use%20a%20Static%20MAC%20address.pdf

    which states,

    NOTE: Microsoft Virtual Machines static MAC addresses must be within the following range:              

    Minimum Mac Address = 00-15-5d-01-80-00              

    Maximum Mac Address = 00-15-5d-01-8F-FF

    So, must I? 

    The reason I ask is that we are converting a physical server into a VM and retiring that physical server.  One of the programs on that server has licenses that are tied to that server's MAC.  I'd like to reuse that MAC.  As long as we avoid network collisions on our small network (about 20 physical and virtual machines) which is a closed loop system (i.e. not connected to the internet), I don't understand the above must statement.

    I didn't read the article, but if they are trying to say that you must use something in that range, then the article is wrong. Microsoft owns the 00-15-5D prefix and will use that for all MACs that it automatically generates. That's it. There is no rule of any kind that says that you must use one of theirs for your own internal systems. Override and use any MAC that you want. The application vendor might get upset about it, so Tim is right that you should probably talk to them before you do anything. But, Hyper-V includes the ability to completely override the MAC of any virtual machine and it will not stop you from using something outside its default range.

    Eric Siron
    Altaro Hyper-V Blog
    I am an independent contributor, not an Altaro employee. I accept all responsibility for the content of my posts. You accept all responsibility for any actions that you take based on the content of my posts.

    Tuesday, November 5, 2019 9:10 PM
  • Hi,

    Was your issue resolved? 

    If you resolved it using any above solution, please "mark it as answer" to help other community members find the helpful reply quickly.

    If you resolve it using your own solution, please share your experience and solution here. It will be very beneficial for other community members who have similar questions.

    If no, please reply and tell us the current situation in order to provide further help.

    Best Regards,

    Lily

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

    Monday, November 11, 2019 1:25 AM