[CentOS] Strange XEN on CentOS HWaddr Address Issue

Christoph Maser cmr at financial.com
Tue Aug 4 13:09:33 UTC 2009

Am Dienstag, den 04.08.2009, 14:43 +0200 schrieb Brett Serkez:
> Ran into a strange issue with XEN on CentOS that I think is specific
> to CentOS, which is why I'm starting by posting to this list first,
> I'll post on the XEN list depending on responses.  My sense is this
> issue has something to do with how CentOS handles network setup on
> first boot of the XEN kernel.
> - Installed a brand new CentOS 5.3 server with minimal packages.
> - Installed XEN, modified grub.conf to boot off of the XEN kernel and rebooted.
> - After reboot, network connectivity was lost.
> - Investigation concluded the issue was that the HWaddr address of the
> physical NIC matched the fabricated HWaddr that XEN uses for most of
> its adapters:  FE:FF:FF:FF:FF:FF.

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
All Xen vif devices will show also MAC FE:FF:FF:FF:FF:FF. That is
totally normal.


financial.com AG

Munich head office/Hauptsitz München: Maria-Probst-Str. 19 | 80939 München | Germany
Frankfurt branch office/Niederlassung Frankfurt: Messeturm | Friedrich-Ebert-Anlage 49 | 60327 Frankfurt | Germany
Management board/Vorstand: Dr. Steffen Boehnert (CEO/Vorsitzender) | Dr. Alexis Eisenhofer | Dr. Yann Samson | Matthias Wiederwach
Supervisory board/Aufsichtsrat: Dr. Dr. Ernst zur Linden (chairman/Vorsitzender)
Register court/Handelsregister: Munich – HRB 128 972 | Sales tax ID number/St.Nr.: DE205 370 553

More information about the CentOS mailing list