eth0 not found

[akc42]

I upgraded one of my remote systems this morning and did a reboot. It failed to come up so that I could ssh back into it. Looks like a visit to the remote site is required. This is raspbian initially installed as Jessie, but recently upgraded to Stretch.

I have a local copy of that system and so did the same update (sudo aptitude - then hit the u and U keys - finally g to do the update) and sure enough networking is broken with cannot find eth0 when it tries to bring up the interfaces in service networking start.

I found a blog post that describes this problem uses `networkctl` to find the name that the interface is actually called and then uses `ip link set xxx name eth0` to rename the network to eth0. Doing this I networking now correctly brings up eth0.

However it then goes on to describe creating a /etc/udev/rules.d/70-persistent-net.rules file to allow the booting system to rename to eth0 automatically. However I tried this and it doesn't work.

I've been poking around to see what is there and found a set up rules in /lib/udev/rules.d - but I have no idea what they are trying to do and whether they are even being used.

How can I make the network name change permanent. I obviously want to figure it out locally before making the journey to the remote site.

[akc42]

Looking at the log during boot I get this

[ 2.656953] smsc95xx 1-1.1:1.0 eth0: register 'smsc95xx' at usb-3f980000.usb-1.1, smsc95xx USB 2.0 Ethernet, b8:27:eb:1c:5c:a3
[ 2.663049] smsc95xx 1-1.1:1.0 enxb827eb1c5ca3: renamed from eth0

Which sort of says it was called eth0 but now its changed itself to something else. And indeed enxb827eb1c5ca3 is the name found for that interface

[rpdom]

Run sudo raspi-config
Select 2 Network Options
Select N3 Network interface names
Choose <No>
Exit and reboot.

[akc42]

Run sudo raspi-config
Select 2 Network Options
Select N3 Network interface names
Choose <No>
Exit and reboot.

I'll give that a go shortly - I did find an alternative solution :-

Code: Select all

sudo cp /lib/udev/rules.d/73-usb-net-by-mac.rules /etc/udev/rules.d/73-usb-net-by-mac.rules

Edit the new file to change the 3rd to last line to

Code: Select all

 
IMPORT{builtin}="net_id", NAME="eth0"

The place I found that refered to a ubuntu bug https://bugs.launchpad.net/ubuntu/+sour ... ug/1593379

[Andyroo]

Very strange - not something I’ve had happen on the Pi (Intel is a different box)...

Have you set the MAC address at all as this messed the name up before?

What do you have in /etc/udev/rules.d/70-persistent-net.rule now?

You could also try creating a blank /etc/udev/rules.d/80-persistent-net.rule

Code: Select all

sudo touch /etc/udev/rules.d/80-persistent-net.rule

This should be read last and as it’s blank it should override the rename rules (I think )

[akc42]

Run sudo raspi-config
Select 2 Network Options
Select N3 Network interface names
Choose <No>
Exit and reboot.

I gave this a try, removing my solution beforehand. It didn't work. In fact worse than that in that it prevented my solution from working when I put it back. I had to run

Code: Select all

sudo raspi-config

again and chose <yes> at N3. Before my solution would work again

[akc42]

Have you set the MAC address at all as this messed the name up before?

No never - the remote server has been running for about 18 months perfectly - it was just the upgrade today (which is the first I've done since I upgraded from jessie to stretch a couple of months ago.

Because I have a clone system locally and it has been through the same upgrade processes in parallel I am pretty confident that its an update to the persistent rules in raspbian that have caused the problem. Trouble is they look so complicated now I can't get my head around what they are supposed to do.

What do you have in /etc/udev/rules.d/70-persistent-net.rule now?

Nothing - see my solution about and the link to the regression in ubuntu. I suspect that raspbian has this same regression.