Hi guys!

Yet another short post this time!

I've been building machines, which have to be totally interchangeable, and discovered that when I swapped a hard drive between motherboards, that Slackware would increment the ethernet device(s). eth0 would become eth1, eth0 and eth1 would become eth2 and eth3. What's worse, if I plugged a few different wireless dongles in, every single one would have a new number! This was an utter pain in the backside for trying to use code which assumed eth0 or wlan0; also, it seemed ridiculous that we could end up with systems with completely different configurations, so I set out to find how to stop this happening.

The offending configuration file was /lib/udev/rules.d/75-persistent-net-generator.rules. This causes udev to keep track of the MAC addresses of the network interface, and to assign a persistent interface name. It creates the file /etc/udev/rules.d/70-persistent-net.rules and populates it with a rule for every new device attached.

To stop this evil behaviour, simply delete the generator file (/lib/udev/rules.d/75-persistent-net-generator.rules).

Nice and simple!

n00b