I have a dedicated server with Windows 10 - far away from me, in datacenter.

I create external switch in Hyper-V to connect my VMs to Internet with "white" IPs. I attach it to NIC with internet (server also have other NIC, but it not connected, maybe for datacenter local network, I think).

When I apply this external switch, my host lost internet in browser (!), but I still have connection by RDP without any problem (!). Somehow I see my server in Internet, but my server not see Internet.

On previous server I have connection with external switch without any problems. What can be cause of problem? Maybe it something with new 'Default Switch' in Hyper-V, that cannot be deleted?

  • Win10 isn't ideal as a server, but what you're seeing is expected. When you configure an external virtual switch, the networking information (TCP/IP info) is moved off the physical NIC and onto the new virtual switch. The default virtual switch is a non-configurable NAT implementation, there's no reason to use it, if you're using an external switch. Do you have MAC restrictions, as you're new virtual switch will have a different MAC than the physical NIC. Have you verified that all the TCP info is correct, maybe the gateway is missing? – essjae Sep 10 '19 at 17:28
  • @essjae thank you for your attention! Hyper-V somehow erase DNS-server entries from main connection when it creates external switch (and bring it back when I remove switch). – Deromanenko Sep 11 '19 at 6:49

I think I found a solution:

When Hyper-V creates an external switch, it removes the DNS-servers from main connection settings. After switch delete - it restores it back.

So I wrote it manually to main connection - and everything works fine.

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