Description of problem:
Using FC5 with xen, a required pethX device is not created and the xenbr0 bridge
is created with the wrong pethX device.


Version-Release number of selected component (if applicable):
   xen-3.0.1-4
   kernel-xen0-2.6.16-1.2080_FC5


How reproducible:
My system has two real ethernet devices, with static IP's, configured as follows:
   eth0: 192.168.2.1, physically on my LAN
   eth1: my assigned ISP address, physically connected to the ISP

Both eth devices are configured to start on boot, and this works well.

I am using firestarter as my firewall, and have configured NAT forwarding to
allow my LAN to connect to the internet. This works fine with my dom0 kernel.

When I reboot, "ifconfig -a" shows eth0, eth0, all of the vif0.X devices, all of
the vethX devices, and peth1. peth0 is not there. xenbr0 is:
xenbr0          8000.feffffffffff       no              peth1
                                                        vif0.0

The problem here is guest vm's need to be part of my LAN on eth0, not on the
internet. If I had a peth0 device I could replace it in the bridge, but the
device doesn't even get created.

If I swap the assignment of eth0 and eth1 by swapping the MAC assignments, such
that my LAN is eth1 and the internet is eth0, I end up with a peth0 and no peth1.

If I swap the assignment of eth0 and eth1 by swapping the IP's assigned, again I
end up with a peth0 device and no peth1. It seems that xen has a bias towards my
real IP as when both real interfaces are present it will only create a pethX for
the one with my ISP-assigned address.

If I disable eth1 (back to being my internet connection) from coming up at boot
time, xen creates a valid peth0 and I am able to communicate with my guest vm's
through my LAN.