New
#21
Glad to find this, and surprised an issue of this nature is still not fixed. I notice one work-around is missing from this thread, so thought I would add it:
The problem: Creation of a new external virtual switch in HyperV Manager causes Host file sharing to be disrupted. Specifically, it appears that the services associated with physical adapters get set correctly, but something below the hood for File and Print Sharing gets broken.
Solutions:
As said in earlier posts, if the new "Default Switch" works for you, it is the least problematic option. Delete any manually created external virtual switches and set the network adapter for each VM to "Default Switch" to take this option.
Unfortunately, you cannot assign a distinct IP address to the Default Switch. So this may not work for all users.
Another option not discussed yet works for users with multiple physical network connections. You can use one physical adapter for the host machine, and a different one for the virtual switch. When creating the virtual switch, uncheck the box to allow the host machine to share the connection.
You'll notice that even though this setup has the virtual switch completely separated from the host machine's networking, the host machine's file sharing still gets broken. However, simply get properties of the physical network adapter for the host machine, remove all protocols and apply. Then add them back and apply. This will restore functionality.
Some have noted that they had to redo this every time they restarted their machine. I haven't confirmed this yet, but it is likely. Ugh.
This solution will did not work for me with a single physical network shared with the host machine. It required adding an Ethernet port. I think if I had only one port, I would use Kari's suggestion from post #18 above.