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2 Hyper-V guest will not talk to eachother

I am using a NUC with Windows 10 Pro (build 10.0.19042). Connected to LAN using WiFi. I.e. no cable.
I have downloaded a Windows Server 2019 (trial version).
(In the end I want to do some testing on AD using 2-3 virtual servers)
I then created 2 Hyper-V machines connected to network using the "Internal"  of Virtual switches.
Starting up the 2 VM's showed me ip adresses in the 169- and 164-range (>ipconfig /all).
I was incorrectly expecting it to use IP-adresses from DHCP-server on the host.
I then set the IP-address to a fixed address on the VM (in the same range as the host) by doing the following:
Control Panel --> Network and Internet -> Network Connection --> Ethernet (this is the only choise)
Connect using: Microsoft Hyper-V Network Adapter
In the list of items:
--> Internet Protocol Version 4 (TCP/IPv4) --> Properties:
I set all the other parameters to the same as on the Host (subnet mask, default gateway)
I set the DNS servers to fixed addresses (as on the host)

I then reboot the VM's, but when starting up again and checking Network Connection it says
"Unidentified network" on Microsoft Hyper-V Network

What am I missing ?
I would expect to ping between the 3 entities (2 VMs and one Host). Have I misunderstood something ?


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Avatar of Bembi
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If you want to connect you Hyper-V clients to the physical NIC of the host, use External Network an select the according interface.
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From what i understand the "Private" option on the virtual Switch should give possibility to communicate between VM on the Host. If Internal was used it should give additional possibility to communicate to Host. I assume Host NIC is used for the latter. Is this incorrect ?
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External: Allow communication over the HyperV connected LAN Adapters.
Internal: Allow communication between HyperV Guests and HyperV Host
Private: Allow communication between HyperV Guests.

If HyperV Guest should talk to each other, they should use the same virtual switch. So if your DHCP is on a different virtual switch, the other VMs will not get an IP from the DHCP.  
Avatar of ITguy565
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Do you have VLAN's Configured on this network? if so I might recommend that you use the nic teaming option on the host then create virtual nics for each vlan.  That beside the point.. If all that is in order, then the other experts are correct, your issue resides most likely on your virtual switch configuration in Hyper-V manager.
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Philip Elder
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Private = Internal to the VMs only
Internal = Shared with Host only
External = Connected to the same LAN the shared virtual switch is on

If using a Private vSwitch, then set up a VM with a Private _and_ an External vNIC and use Untangle, SOPHOS Free, or Server 2012 RTM/R2 RRAS as a router between that "Private" network and the "Internet" provided by your network.

Our first VM to be stood up in this scenario (lab) is a DC that has a greenfield AD, DNS, and DHCP. It does get a static IP/subnet. We then move on to set up the rest of the VMs needed.

I have two very thorough EE articles on all things Hyper-V:
Some Hyper-V Hardware and Software Best Practices
Practical Hyper-V Performance Expectations

Some PowerShell Guides:
PowerShell Paradise: Installing & Configuring Visual Studio Code (VS Code) & Git
PowerShell Guide - Standalone Hyper-V Server
PowerShell Guide - New VM PowerShell
PowerShell Guide - New-VM Template: Single VHDX File
PowerShell Guide - New-VM Template: Dual VHDX Files

Here are some focused articles:
Set up PDCe NTP Domain Time in a Virtualized Setting
Slipstream Updates Using DISM and OSCDImg (keep your Windows Desktop/Server .ISO files up to date)
Protecting a Backup Repository from Malware and Ransomware
Disaster Preparedness: KVM/IP + USB Flash = Recovery. Here’s a Guide
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Thanks folks.
Very useful input.
@Philip: I will probably try your suggestion on router setup between the Private and the External after doing my initial AD testing. + Thanks for super best practice tip

Seems like my initial problem was related to a prosaic issue having the VM's firewalls set up correctly.
Case closed (for now).

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