The Teredo State machine setting should be configured correctly. This policy setting allows you to configure Teredo, an address assignment and automatic tunneling technology that provides unicast IPv6 connectivity across the IPv4 Internet. If you disable or do not configure this policy setting, the local host settings is used. If you enable this policy setting, you will be able to configure Teredo with one of the following settings: Default: The default state is "Client." Disabled: No Teredo interfaces are present on the host. Client: The Teredo interface is present only when the host is not on a network that includes a domain controller. Enterprise Client: The Teredo interface is always present, even if the host is on a network that includes a domain controller. Fix: (1) GPO: Computer Configuration\Administrative Templates\Network\TCPIP Settings\IPv6 Transition Technologies\Teredo State (2) KEY: HKLM\Software\Policies\Microsoft\Windows\TCPIP\v6Transition\Teredo_State