[xen-tools-discuss] Re: Eth0 device on Debian guest on Fedora 8 Dom0

[Anton Dollmaier]

Hi Mike,



> Hey, running into another problem that may or may not be xen-tools
> related.  When the xen-tools image was created I a MAC address for the
> guest Eth0 device was chosen.  Now if I try to change the vif= line in
> the config file to any other MAC address the guest OS fails to detect
> the Eth0 device.  Somewhere something is bound to this initial MAC
> address and so far I have failed to locate it and I can't find any
> similar problems online.  Do any of your know what I am missing here?


this is a debian, or specifically udev, issue:

check this file:

/etc/udev/rules.d/z25_persistent-net.rules


udev maps each mac to an own ethernet-interface ... new mac, eth0 is 
already used, so udev installs the new device as eth1 - which doesn't 
have a network-config in /etc/network/interfaces, so there is no network 
available ...

so, when changing the mac, either correct the mac there too, or remove 
the file before first boot.

this happens not only with xen, but also if you change the NIC or the 
mainboard with onboard-NIC ... cost me already some hours ;-)



greetings,

Anton