I'm experience strange connectivity issues on a Windows Server 2012 R2 Standard installation with installed Hyper-V role and one Server 2012 R2 guest machine.

Whenever the Guest tries to access the internet, the hosts network is completely frozen.

The host machine is a dedicated server, so we have no physical access to it. The configuration is as follows:

The host has 1 NIC that uses dynamic IP adress (This is provided by a DHCP server from the datacenter in which the server is hosted). Hyper-V Extensible Virtual Switch and Microsoft Network Adapter Multiplexer Protocol are disable there. A vEthernet connection is set up in the host as well with the same properties except that the IP is static here (I'm using for the host).

The virtual machine has one virtual network adapter where I set the IP to and the default Gateway to the host machine ( The virtual switch in Hyper-V for the guest is set to "Internal Network" with no VLAN.

I'm using "Routing and Remote Access" on the Host so I can set up a NAT for the guest VMs.

However, I can not access windows update or windows activation from the guest machine. Pings and HTTP (Internet Explorer) are working for the public internet. For example, windows update gives the following Error code: 8024401C

The problems are that I constantly lose network connectivity for about 5 to 10 seconds, and the host is no longer accessibly then (RDP, FTP and Ping all fail to the public IP adress of the host).

Can you tell me where I configured something wrong?


  • To clarify. Your host (physical machine) has 1 NIC and it's IP is dynamically assigned via DHCP? – Citizen Feb 20 '15 at 9:34
  • Yes, exactly. I have no control over the DHCP server whatsoever, so I cannot assign an external network for the VM. – GeorgDangl Feb 20 '15 at 9:39
  • Can you assign a private IP to rule out the lease renewing as a potential issue? – Citizen Feb 20 '15 at 22:31
  • What do you mean with private IP? The guest and host connect via the VMSwitch, only the host is exposed to the "outside world" since the server hoster blocks any communication that uses a different MAC adress. – GeorgDangl Feb 20 '15 at 23:11
  • So your saying the physical host has a public IP address that is DHCP assigned and people access guests through......this IP? – Citizen Feb 21 '15 at 0:25

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