I am taking over an issue, with a Server 2012 Hyper-V host, and a Windows 2008 R2 VM.
There is a external Virtual switch setup, but other servers can not communicate with the 2K8 VM and vice versa.
I have removed the virtual switch and recereated it and still no joy. The 2K8 VM will eventually act as DNS server.
Any advice would be appreciated...