Again, things aren’t as easy as one could hope.

After my obvious fix to the xenon_net kernel module, I’ve noticed that after every reboot, the interface name incremented by one. I’ve now got up to eth5!

At first I was very puzzled, but obi was able to identify the issue: The debian udev scripts are trying to preserve interface names for removed network adapters. They are matched on the MAC-address which is - random, in our case.

My /etc/udev/rules.d/z25_persistent-net.rules looked like

[...]
# PCI device 0x1414:0x580a (xenon_net)
SUBSYSTEM=="net", DRIVERS=="?*", ATTRS{address}=="00:01:02:03:04:05", NAME="eth1"

# PCI device 0x1414:0x580a (xenon_net)
SUBSYSTEM=="net", DRIVERS=="?*", ATTRS{address}=="66:b1:d7:4f:ce:2b", NAME="eth2"

# PCI device 0x1414:0x580a (xenon_net)
SUBSYSTEM=="net", DRIVERS=="?*", ATTRS{address}=="06:4f:ae:06:eb:c3", NAME="eth3"
[..]

My fix was to remove the ATTRS, like:

SUBSYSTEM=="net", DRIVERS=="?*", NAME="eth0"