How-to get rid of virbr0 and or virbr1 in KVM guests

How-to_get_rid_of_virbr0_and_or_virbr1_in_KVM_guests.txt

I have installed some RHEL 7.4 that were custom built by someone.  They were intended for a bare-metal OS so they
have full virtualization enabled.  This means libvirtd is automatically started and there are virbr0 and sometimes virbr1 
bridges enabled.  This usually causes the KVM guest to not have any access to any network via NAT because the bridges
are trying to route all traffic.

Here is a website I found that I found useful:

  https://www.cyberciti.biz/faq/linux-kvm-disable-virbr0-nat-interface/
  
  The following commands will probably work to disable the two bridged networks.
  
  # virsh net-destroy default
  # virsh net-undefine default
  # service libvirtd restart
  # ifconfig 
  
I think a better way is to remove the rpms for libvirtd or just do the following (my solution for now):

  # systemctl disable libvirtd
  # systemctl stop libvritd
  
  After a reboot, virbr0 and virbr1 should be gone.