Last modified at 5/7/2014 6:39 PM by Koen Zomers
In times it might be necessary to change the IPv6 DHCPv6 unique identifier (DUID). This might be the case for example where you have copied a Hyper-V image with an IPv6 enabled OS on it and are trying to use both copies at the same time on the same IPv6 DHCPv6 enabled network. This will result in errors stating that there's an IP conflict on the network. In this case you can reset the DUID so the image will get assigned a new DUID and thus receive a new IPv6 address from the DHCPv6 server.

In order to reset the DUID, follow these steps:

  1. Open the Registry Editor. I.e. by pressing Windows+R and typing regedit followed by enter.

    IPv6_Reset_Duid_RunRegedit.png

  2. Browse to the following registry key:

    HKLM\System\CurrentControlSet\services\TCPIP6\Parameters

    IPv6_Reset_Duid_Regeditkey.png
    In there, right click on the Dhcpv6DUID entry and click on Delete

    Alternatively you can also delete the registry key directly with the following command:

    reg delete HKLM\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters /v Dhcpv6DUID

    IPv6_Reset_Duid_DeleteRegKeyCommand.png

  3. Restart the Windows machine. During boot it will automatically recreate the registry key with a new value.