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

Mon Jun 23 04:29:20 UTC 2014
Arun Khan <knura9 at gmail.com>

On Thu, Feb 20, 2014 at 3:36 AM, Dusty Mabe <dustymabe at gmail.com> wrote:
> On 02/19/2014 04:01 PM, James B. Byrne wrote:
>>> 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.
> http://wiki.libvirt.org/page/Networking#Bridged_networking_.28aka_.22shared_physical_device.22.29

+1 to Dusty's solution.

@OP please post the output of 'brctl show'  see below for example.

$ /usr/sbin/brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.002590d3f56e       no                     eth0


In the VM definition, you need to define the VM's NIC bonding to the
bridge interface (in my case VM's NIC is vnet0 and it is bridged to
br0 which interfaces to the LAN via eth0).

Also, when you define the bridge, the host IP is assigned to the
bridge device (br0) and not to the physical device eth0.

-- Arun Khan