I am trying to add DHCPv6 reservations on a Windows Server 2012 R2, but I do not want to use the "random" IPv6 the server chose (convert lease to reservation), but I want to use another, specific IPv6. This operation fails, however, with error 20222 (address or DUID already in use).
I have tried to release the IP on the client using ipconfig /release6
, which removes the IP from the client and from the list of leases on the server. However, it does not fix the problem.
I tried to remove the lease on the server using Remove-DhcpServerv6Lease
, which removes the lease from the list of active leases, but does not fix the problem either.
I have tried doing the reservation when the scope is deactivated without success.
I have tried restarting the DHCP service without success either.
If I list the active leases using Get-DhcpServerv6Lease -Prefix $prefix
, I can neither find the DUID nor the IPv6 I want to reserve, but the operation still fails.
Where does the server get the information that the IPv6/DUID is already in use and how can I fix this?