1

I’ve got a Windows Server 2016 server with several guest VMs. The server has 4 physical NICs aggregated with NIC teaming, then connected to a Virtual Switch in Hyper-V. The virtual switch is used by the guest VMs and the Hyper-V host. The option to “Allow management operating system to share this network adapter” is enabled in the virtual switch settings.

The host can communicate with everything on the network except the guest VMs. The guest VMs can communicate with each other without any issues. Can anyone advise why this would be? Logically they’re connected to the same network so I can’t see why they can’t communicate.

7 Spice ups
2

Are you using a Hyper-V internal or private virtual switch type?

1 Spice up
3

Nope, I’m using External.

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4
  • Can the VMs communicate with anything outside the host or the host itself (example like hit file shares outside the host, DCs, etc.)?
  • Are you just testing ICMP pings from the host to the VMs? Can the host hit shares files on them, SMB, etc?
  • Are there are OS firewall updates that need to be adjusted on the VMs?
5
  • The VMs can communicate with everything except the host. Likewise the host can communicate with everything except the VMs
  • Same result with file shares, it just behaves like they don’t exist
  • I have tried disabling windows firewall on both the host and guests but it didn’t help
6

Are the VMs set to use any VLAN tagging?

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7

Does the network profile of the VM need to be updated in the OS?
How to Change Your Network Profile to Public or Private in Windows 10 .

8

No they’re not set to use any VLAN tagging.

The VMs network profile is set to DomainAuthenticated. The host is not part of the domain, but has no problem communicating with other domain joined servers/PCs that are not guests so it can’t be that.

9

That issue happened to me as well.

Are you using LBFO or SET Team? LBFO is considered a legacy and may cause problems.

Have you already tried removing the existing virtual switch, removing the team, and recreating everything from scratch? That fixes those kinds of problems in most cases.

As a troubleshooting step, you may remove one of the NICs from the team and let the hypervisor host use it directly to see if that resolves the problem.

Try changing the host (Team NIC) IP address to see if that changes anything, and try adding another network adapter to one of the virtual machines pointing to the same virtual switch and see what happens.