After two replacement chassis in quick succession (timekeeping problems, followed by blown power supply), one of my machines was showing its two ethernet ports as
eth5. This probably isn’t an issue in and of itself*, but if I ever have to do stuff manually with the ethernet ports I don’t want to have to remember that they’re nonstandard.
A little digging (specifically,
grep -R eth /etc/*) revealed that this gets set in
/etc/udev/rules.d/z25_persistent-net.rules, so I edited it to take out the old eth* MAC addresses and relabel the new ones. Unfortunately, restarting
udev didn’t make the change happen, so I had to reboot.
* I thought it was, because I couldn’t get either port to come up, hence discovering the above. However, after fixing that it still wouldn’t work — turned out that the cable was out at the other end. Always check the obvious stuff first! At least I learnt something.