With Windows Server 2012, Microsoft added Hyper-V DHCP Guard feature. This feature can be enabled on VM NICs and it discards DHCP Offer messages.

Below is a figure about DHCP Lease process:

When DHCP Offer packets are blocked, a DHCP server cannot offer an IP address.

How DHCP Technology Works: http://technet.microsoft.com/en-us/library/cc780760(v=ws.10).aspx

In other words, this feature blocks virtual machines from acting as DHCP servers. This feature is very useful to prevent rogue DHCP servers running on VMs in your Hyper-V environment.

How to enable Hyper-V DHCP Guard feature using UI?

  • Using Hyper-V Manager administrative tool, do a right click on your VM and then click on Settings…

  • Go to Advanced features under the VM NIC and then check Enable DHCP Guard option. Once done, click on OK

How to enable Hyper-V DHCP Guard feature using PowerShell?

Set-VMNetworkAdapter with DhcpGuard switch can be used to enable DHCP guard on VM NICs.

Set-VMNetworkAdapter: http://technet.microsoft.com/en-us/library/hh848457.aspx

We can take the following example which enables DHCP Guard feature on all NICs for Server1 VM:

Get-VMNetworkAdapter –VMName Server1 | Set-VMNetworkAdapter –DhcpGuard on

See Also