On Aug 4, 2009, at 12:50 PM, Ross Walker <rswwalker at gmail.com> wrote: > On Tue, Aug 4, 2009 at 12:30 PM, Brett Serkez<bserkez at gmail.com> > wrote: >> 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. > > Maybe because you are looking at the bridge's mac and not the > ethernet's which would be peth0. Actually that would be peth1 For a Xen server I find it better to disable the Xen network scripts and setup a static bridged or routed setup. Then it is predictable and iptables is infinitely easier to setup. -Ross