On 1/30/20 1:42 PM, Bob Weber wrote:That's why I recommended you look into systemd link files.I looked that up on the 'Net, and it seems pretty reasonable. I looked around a bit and was told to edit /usr/lib/systemd/network/99-default.link (MAC addresses are back to hardware again, but easier to handle -- at least they're the same whenever you look at them. And Debian puts config files in /etc. Used to, anyway) There's a line in 99-default.link about <something>=persistent. The web says that if I change that to 'none' I'll get the old names back. I did, and I didn't.Systemd has the undesired effect of renaming interfaces. You need to use the MAC address to indicate which port should be eth0 , etc.It looks like it'll take a lot more than changing a value in a config file to have happen what I expect. I think I'll just leave things alone for the time being. Now I know to expect systemd to break things, and now I know to write around it. I was completely at a loss when those numbers just changed for no apparent reason. Counting Ethernet interfaces isn't rocket science. Again, thanks list.
That's why I showed in theprevious email a file for eth0 and eth1
matching their MAC address. The "99-default.link" file is taken
out of the works by (symbolic) linking it to /dev/null. This
means whatever was in that file messing up the port names is
gone. The kernel command line option "net.ifnames=0" may or may
not be needed ... try without at first.
After a reboot the names should be what you put in the [Link]
section of the files " /etc/systemd/network/10-eth0.link" and "/etc/systemd/network/20-eth0.link"
assuming you put in the correct MAC address in the [Match]
section.