[CentOS-virt] MS-Win7 kvm guest gets dhcp from host bridge

Wed Feb 19 22:06:05 UTC 2014
Dusty Mabe <dustymabe at gmail.com>

On 02/19/2014 04:01 PM, James B. Byrne wrote:
> CentOS-6.5
> i86_64
> qemu-kvm-
> MS-Windows v7proSP1
> We have installed a MicroSoft Win7 system as a guest and have joined it to our
> MS AD domain. The system runs and has internet access.  However, the IPv4
> address it obtains and the gateway it is assigned are both sourced from the
> virtual machine host system and not from our AD DC DHCP server.
> To clarify, the virbr0 IP address is and the Windows guest has
> that address as its gateway and an IP address in the
> netblock.  This is not as we desire as the internal addresses we regularly
> assign to MS workstations via DHCP are supposed to belong to a different
> netblock entirely.  This permit filtering on incoming and outgoing traffic at
> the gateway.
> I realize that there is a DHCP service running on virbr0 for the purpose of
> provisioning guests with system control traffic but I do not know how to limit
> that to its intended purpose and allow another DHCP server to provide the IP
> address to the windows guests.  I hope that problem description is not too
> confusing.
> Can anyone provide me with some guidance on the matter?  Are kvm guests
> required to have either static ip addresses or dhcp addresses provided by the
> host system?

It sounds like what you need to do is create a bridge and then connect 
your virtual machine to the bridge so that it can receive DHCP from the 
external network.  I assume you are using libvirt. If so, check out the 
page below. It may help you get started in the right direction.