[libvirt] Network Interface: How to disable virbr0 correctly?

Hi all, Recently, I have been using libvirt to create virtual machines on ESX servers. It has been very well until to the point where I couldn't find any way to disable/remove the virbr0 interface properly. We use static configuration for VMs on ESX so we do not need to use virbr0 interface and we do not want libvirt to configure iptables as a result of the newly created virbr0 interface. I have tried to remove/rename the /etc/libvirt/qemu/networks/autostart.xml file, and that prevents virbr0 being installed. However, that also seems to prevent the second interface eth1 being configured properly. After libvirt defines a VM, eth0 and eht1 are both installed, but only eth0 is configured properly. The eth1 does not appear in the /etc/sysconfig/network-script/ifcfg-xxx file. It seems to me that the 'autostart.xml' file interrupts the configuration of the eth1 interface. Can anyone please advise how I can do this properly? Thanks a lot, Jake