Brett, I think the following link answers your question about the MAC changes. You may find more useful links on the resources page of the Running Xen site http://runningxen.com/resources/. http://lists.xensource.com/archives/html/xen-users/2006-02/msg00030.html If you performed a fresh install without Xen, you would notice that it has not permanently modified the MAC address of your system. Hope that helps. Matt -- Mathew S. McCarrell Clarkson University '10 mccarrms at gmail.com mccarrms at clarkson.edu 1-518-314-9214 On Tue, Aug 4, 2009 at 1:30 PM, Brett Serkez <bserkez at gmail.com> wrote: > > Maybe because you are looking at the bridge's mac and not the > > ethernet's which would be peth0. > > No I am not. dmesg shows the kernel messages at boot and it is > looking at the physical device, let's not get distracted, the issue is > clear in this regard. As I previously stated, this happens even when > uninstalling XEN and booting off the non-XEN kernel since the install > of XEN. > > > indeed, AFAIK all hardware adapters start with 00. This must have been > set > > in the BIOS or with a boot option or in the network config. > > This was helpful, gave me places/incentive to continue looking. > > In /etc/sysconfig/network-scripts/ifcfg-eth1 I found: > > # Realtek Semiconductor Co., Ltd. RTL-8169 Gigabit Ethernet > DEVICE=eth1 > BOOTPROTO=none > HWADDR=00:40:F4:CE:E6:7B > > So now I know what the original MAC address was. > > Here is where it gets interesting. The following file was modified at > the date/time that the XEN kernel was first booted: > > /etc/sysconfig/hwconf > > and it has fe:ff:ff:ff:ff:ff for BOTH network adapters: > > desc: "Realtek Semiconductor Co., Ltd. RTL-8169 Gigabit Ethernet" > networfe:ffddr: fe:ff:ff:ff:ff:ff > vendorId: 10ec > deviceId: 8169 > subVendorId: 10ec > subDeviceId: 8169 > pciType: 10 > > desc: "Intel Corporation 82562EZ 10/100 Ethernet Controller" > network.hwaddr: fe:ff:ff:ff:ff:ff > vendorId: 8086 > deviceId: 1050 > subVendorId: 8086 > subDeviceId: 303a > > Everything I'm finding is re-enforcing my original theory that XEN > modified the hwaddr of this NIC. > > The question continues to be what caused this and how to change it > back. Given this is a stock system, I have to believe others must > have/may run into this issue. > > Brett > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20090804/19639a1a/attachment-0003.html>