Network interfaces suddently renamed after reboot.

[mgnut57]

After a reboot, my network interface names got messed up. I would appreciate any advice on fixing this.

I have 3 physical interface devices:

[Ant P.]

Where does ip_vti0 come from?

[mgnut57]

[Ant P.]

/sys/class/net/ should have a symlink telling which driver owns it.

[mgnut57]

[Ant P.]

Something on your system is renaming that virtual interface to eth0, causing your ethernet cards to become misnumbered. That's not default or expected behaviour on any distro I've used, but I don't use systemd so I can't say if it's trying to be “helpful” here.

[mgnut57]

[UberLord]

[mgnut57]

[Tony0945]

Are you using eudev? You should be. I can't tell from the files because they have the same names.
The later versions of udev only work with systemd

On my server with eudev

[mgnut57]

[Tony0945]

See "Migrating from udev to eudev" on the wiki https://wiki.gentoo.org/wiki/Eudev

You may have to uninstall udev. Try the wiki instuctions and see what happens. Report any blockers back here.

[mv]

[Leio]

sys-fs/udev is meant to be used when NOT having systemd, just like eudev. So it is your choice if you use udev or eudev.
udev is compiled from systemd tarball and is the main tested thing (by the majority of other popular distros), and eudev is a fork that sometimes gets updates pulled from udev.
There may be some out of the box default differences in terms of network naming and such, but if that's the case, udev can presumably be configured to behave like eudev does by default, should you so choose.

Just clarifying that NO, you don't HAVE to convert, only if you want to choose that.
_________________
GNOME team lead; GStreamer; MIPS/ARM64

[mgnut57]

[NeddySeagoon]

mgnut57,

Its a bad thing to rename anything to names allocated on a first come first served basis by the kernel.
Add

[Leio]

net.ifnames=0 disables the predictable network naming feature, so I don't see how the suggestion matches the intent.

eth0 and eth1 ARE the unpredictable names, depending on a first come first serve basis and may swap around on different boots, as I understand it.

The predictable network names feature solves that. Though I don't know what that ip_vti0 is about - searching suggests a swan VPN thing. I would expect something like "enp2s0", "ens1", "eno1" or such, depending what the network device is attached to.
But yes, net.ifnames=0 is one way to disable the predictable network names feature, thus have eth0, eth1, etc as far as udev is concerned (if udev is doing the renaming). sys-fs/udev prints out a rather long information at the end of its (re)install/upgrade on how to achieve that as well, including other methods how to disable the feature.
_________________
GNOME team lead; GStreamer; MIPS/ARM64

[NeddySeagoon]

Leio,

My main point was that eth0 is a rename of another interface. net.ifnames=0 is more a diagnostic than a fix.
It will let us see the real names of the interfaces.

I don't know what ip_vti0 is either but I'm fairly sure its not a kernel name.

Being old and cynical, I'll just say that the predictable network naming feature just swaps one set of corner cases for a different set of corner cases and only served to upset a lot of users with a single interface.

I seen kernel interface names swap from kernel to kernel, where several different drivers are in use but never from boot to boot.
Its true that there is a race condition in enumerating several different interfaces that use different drivers.
MAC based interface naming solved that a long time ago and to me, had the advantage that rearranging the cards in PCI slots did not change interface names.

I'm not a fan of predictable network device names.
Its totally broken for USB dongles as they are named after the USB port they happen to gen plugged into. usb0 was much better.
Sorry for the rant ... its drifting off topic too.

I don't use either udev or eudev, so I don't have predictable network naming to turn off.
That's not a path I recommend though.

Hmm ... vti Virtual Tunnel Interface maybe.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[Hu]

[mgnut57]

I agree that the new "predicable" names are anything but.

In my opinion, when you have two identical interface cards (or two interfaces on the same card), the order of the names is not predicable.

[Tony0945]

Leio, thank you for correcting me. In the past, udev depended on systemd which was the impetus for the eudev fork. I was unaware that the situation has changed, as I see no reason to go back.

Hu, I once had a Tyan server board that behaved unpredictably. It had two identical controllers on the motherboard. That was a feature of the board. I had to keep swapping the cable after reboot until I installed eudev and assigned names based on MAC address. I did use eth0 which I recognize was bad. Perhaps I had no trouble because I didn't use the second interface. More recently (last year) I added an Intel board to one of my systems with an existing onboard Realtek. I did this for experimental purposes to see if there was a significant advantage to the Intel. I forced the order by delaying loading the driver module for the Intel board until after eth0 was up and running, ensuring that it would be eth1. I'm still running an older version of OpenRC so all modules are not automatically loaded, only those listed in /etc/conf.d/modules. I loaded the second module in /etc/local.d That might work for the OP but I assumed that he was running a later init system. Besides, I think he has two devices with the same driver.

My 32-bit system also has ethernet devices, different devices and one built-in. When I was using it as a router, I named the faster card lan0 and the slower one wan0 via eudev MAC address rules. I chose those names because they made the firewall rules easier to understand ("Is eth0 the lan or is it eth1, hmmm!"). The "predictable names" I see usable for big servers with multiple identical cards. Even then, as you say, instead of the unpronounceable names, names indicating their network based on MAC (net0, net1... or netadmin, netmanuf, netexec, netadvert, netwww), would seem better and the whole system wouldn't change if one card died.

[Leio]

[NeddySeagoon]

Leio,

Something somewhere is renaming interfaces to the names that the kernel allocates, so there is certainly some renaming going on.
Its odd that the rename is to eth0
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[Goverp]

As an aside, the "predictable" names aren't stable, as I found when I added a USB3 card to my machine. My ethernet card got renamed (which was a surprise, as I think it was a PCI device). At which point I reverted to the old static names. Which does expose me to a dangerous confusion - but only if I ever install a second ethernet card, and I doubt I will!
_________________
Greybeard

[mv]