This policy setting prevents computers from establishing multiple simultaneous connections to either the Internet or to a Windows domain. By default when this policy setting value is Not Configured it is enabled. If this policy setting is enabled when the computer has at least one active connection to the Internet a new automatic connection attempt to the Internet is blocked. When the computer has at least one active connection to a Windows domain a new automatic connection to the same Windows domain is also blocked. Additional manual connection attempts by users to the Internet or to a Windows domain are not blocked by this policy setting. In circumstances where there are multiple simultaneous connections to either the Internet or to a Windows domain Windows disconnects the less preferred connection when the amount of network traffic over the less preferred connection drops below a certain threshold. For example when a computer is connected to Internet using a Wi-Fi connection and the user plugs in to an Ethernet network network traffic is routed through the faster Ethernet connection and the Wi-Fi traffic diminishes. Windows detects this circumstance and responds by disconnecting the Wi-Fi connection. If this policy setting is disabled multiple simultaneous connections to the Internet to a Windows domain or to both are allowed. If this policy setting value is Not Configured the default policy setting is enabled. This is different than enabling the policy setting with Group Policy however - when the policy setting is Not Configured the policy setting is configurable on the local computer. When the policy setting is applied with Group Policy it is not configurable locally. With the policy setting value of Not Configured new automatic connection attempts are not made and less preferred connections are disconnected.
Network\Windows Connection Manager
At least Windows Server 2012 Windows 8 or Windows RT