IPv6 router advertisements
Some computers running Windows 7 or higher are misconfigured and send IPv6 router advertisements into the network. They provide router functions through this mechanism. This can cause massive network disturbances and the network socket will get locked, when this is detected. The problem can be solved by disabling IPv6 fully or by disabling IPv6 router advertisements.
Windows 10:
Windows 8:
Windows 7:
After resolution of the cause unlock the network socket.