Windows Server - Hyper-V breaks DHCP - 1041

Asked By Onetoomany

08-May-08 06:23 PM

I've installed Hyper-V, and created a virtual network connection.
Everything is happy except DHCP - in that I can connect to the internet and
the internet can connect to me.

Looking at the log files, I have a 1041:
The DHCP service is not servicing any DHCPv4 clients because none of the
active network interfaces have statically configured IPv4 addresses, or
there are no active interfaces.

Opening up DHCP and looking under Add Remove Bindings - the list is empty
and I cannot add anything.

It seems that I cannot operate DHCP across a virtual connection that is
switched to a physical connection.

Help?

R

08-May-08 07:28 PM

Where is the DHCP server? On the LAN? On the host? On a guest?

09-May-08 02:45 AM

Should have explained my setup, which is a simple test network:
- Single 2008 server running core networking services (DNS, DHCP, AD) +
Hyper-V
- Single network card
I have a couple of DHCP clients sitting on the network.  All works if I give
them a static IP... so DHCP seems to be the only problem.

R

09-May-08 03:13 AM

Installing Hyper-V makes major changes to the way the NIC in the host
machine works. Runnig DHCP on the host to service LAN machines wouldn't be a
great idea. See this article from Ben's blog.

http://blogs.msdn.com/virtual_pc_guy/archive/2008/01/08/understanding-networking-with-hyper-v.aspx

10-May-08 02:32 AM

give

e

ty


This forum seems to have come up with a solution.  This may be what is
affecting you.

http://forums.microsoft.com/TechNet/ShowPost.aspx?PostID=3D3162313&SiteID=3D=
17

Regards,
Matt

07-Jun-08 08:22 PM

Here is the issue,

When you installed Hyper-V, you checked the check box where it listed
your NIC.

I would recommend using one NIC for HyperV and other one for your DHCP



Onetoomany;3721383 Wrote:


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27-Nov-08 09:10 PM

Short Answer:

Buy another NIC and dedicate it to your Hyper-V tasks.

Long Answer:

Install a second physical NIC on your Hyper-V server and patch it into your network.

Open the Virtual Network Manager in the Hyper-V console and remove all virtual networks

Configure your secondary NIC with an available IP from you LAN and a subnet mask.  Leave the gateway, DNS and WINS empty.

Open the Virtual Network Manager in the Hyper-V console and create a virtual network using the secondary NIC.

Open Add/Remove Bindings on the DHCP server and remove the checks from all bindings except for your NIC.  You may get an ambiguous error about an incorrect parameter which you can ignore.

Restart the DHCP server and open Add/Remove Bindings to verify that the changes you made were saved.

If all went well you should now be able to get DHCP leases from the Hyper-V server’s server primary NIC and use the secondary NIC for Virtual Machine access.

*If you use the Windows firewall, disable it for this process and re-enable it when DHCP works with the Virtual NIC.

This worked for me and I hope it helps to get things working for you. - Jaxplanet

28-Nov-08 03:22 PM

Thank you for the tip.

--
Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on
http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on
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