On Tue, Aug 4, 2009 at 9:09 AM, Christoph Maser<cmr at financial.com> wrote: <snip> > When Xen starts does some trickery with your interfaces. You should see > FE:FF:FF:FF:FF:FF on device peth0 and the real MAC-address on device > eth0. > All Xen vif devices will show also MAC FE:FF:FF:FF:FF:FF. That is > totally normal. I wanted to clarify on this point. Understood as far as the above, but the issue is that the PHYSICAL MAC was changed to FE:FF:FF:FF:FF:FF. This went so far as to still have this value even after rebooting on the standard kernel and then uninstalling XEN: # dmesg | grep eth1 eth1: RTL8110s at 0xee156c00, fe:ff:ff:ff:ff:ff, XID 04000000 IRQ 22 What ever happened during the first boot of XEN caused a permanent change to this NIC as far as I can tell. Brett