I have a Server 2019 host that has a static IPv6 address. It seems Microsoft added a feature in Windows 10 that is also present in 2019 where a host can have both a static IP address, as well as a DHCP address. This feature is enabled by default:
C:\Windows\system32>netsh interface ipv6 show interfaces 3
Interface Ethernet Parameters
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<snip>
DHCP/Static IP coexistence : enabled
I don't appear to be able to disable it though; for testing I ran the command with the "enabled" option that works - but changing "enabled" to "disabled" gives me "Parameter is incorrect".
C:\Windows\system32>netsh interface ipv6 set interface "3" dhcpstaticipcoexistence=enabled
Ok.
C:\Windows\system32>netsh interface ipv6 set interface "3" dhcpstaticipcoexistence=disabled
The parameter is incorrect.
C:\Windows\system32>netsh interface ipv6 set interface "3" dhcpstaticipcoexistence=no
The parameter is incorrect.
C:\Windows\system32>netsh interface ipv6 set interface "3" dhcpstaticipcoexistence=false
The parameter is incorrect.
Am I doing something wrong, or is this just broken? How do we get rid of this additional DHCPv6 address?
Note we have also disabled SLAAC etc as per: Win2k8R2 Obtaining DHCPv6 address, but has static configuration