[libvirt] Can we run guest OS without using NAT and iptables?

[Cole Robinson]

On 10/29/2012 05:30 AM, Stefan Hajnoczi wrote:
> On Mon, Oct 29, 2012 at 12:55:43PM +0530, freak 62 wrote:
>>  Can we run guest o.s. on KVM without enabling NAT and iptables?
>>
>>     The reason to do this is , I wanted to disable conntrack module
>> from my system and to disable that I must have to delete iptable and
>> NAT.
>>
>>      I am getting the following message, when I start guest o.s. on
>> KVM (iptable and NAT disabled):
>>
>>         Error starting domain: internal error 'Network default' is not active.
>>
>>      Is their any way to run guest o.s. with NAT disabled? or Is their
>> any way to disable conntrack module and still can use KVM to run guest
>> OS ?
>>
>>    I am using Ubuntu 10.04

You can remove the default virsh network like

sudo virsh net-destroy default
sudo virsh net-undefine default

The most common networking setup that doesn't use NAT + iptables is probably
bridged networking:

http://wiki.libvirt.org/page/Networking#Bridged_networking_.28aka_.22shared_physical_device.22.29

- Cole