hello -
i'm running into a situation where the systemd predictable network
device names change on bookworm when running the 6.12.22+bpo-amd64
kernel vs the default 6.1 series (6.1.0-34-amd64). i don't see
anything in `/usr/share/doc/linux-image-6.12.22+bpo-
amd64/NEWS.Debian.gz` and haven't found any obvious comment in
`changelog.gz` (although i could definitely be missing something in the latter).
i should be clear that it isn't limited to the bpo kernel; a
trixie/testing system on this hardware has the unexpected (to me)
interface names and installing the 6.12 kernel .deb from trixie/testing
on bookworm has the same behavior. since installing the bpo kernel
package is the cleanest way to replicate i brought it up on the debian- backports list as a first step. the suggestion there was to bounce it
off this list.
with the 6.1 kernel the network interfaces are named `eno1`, eno2`, `enp94s0f0`, and `enp94s0f1` but once booted into the 6.12 kernel they
are named `eno1np0`, `eno2np1`, `enp94s0f0np0`, and `enp94s0f1np1`
(i.e., appending "npX"). the `eno[12]` interfaces are Ethernet
Connection X722 for 10GBASE-T and the `enp94s0f[01]` interfaces are
Ethernet Controller XL710 for 40GbE QSFP+. all use the i40e driver.
i found a similar issue attributed to a change/update in devlink
support in a driver[1] but i haven't found a "smoking gun" changelog
entry. it's possible that the change may have occurred between the 6.5
and 6.8 kernels[2]. i believe it was also reported in the context of
FAI when trying to install ubuntu 24.04 from a bookworm nfsroot[3].
on some level it looks like unintended behavior or a bug. apart from
its disruptive nature, the `enoX` interface names under 6.12 appear to
violate the policy for the on-board naming schemes[4] that says on-
board devices should end in "o[[:digit:]]+" (paraphrased as it was
confusing w/o italics).
on a freshly-installed bookworm system:
# cat /etc/debian_version
12.10
# uname -vr
6.1.0-34-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.135-1 (2025-04-25)
# ip l show | grep -F " en" | cut -d: -f2
eno1
altname enp26s0f0
eno2
altname enp26s0f1
enp94s0f0
enp94s0f1
# udevadm info -e | grep -F ID_NET_NAMING_SCHEME= | sort -u
E: ID_NET_NAMING_SCHEME=v252
# udevadm info -e | grep -F ID_NET_NAME_
E: ID_NET_NAME_MAC=enx3cecefd0da34
E: ID_NET_NAME_ONBOARD=eno1
E: ID_NET_NAME_PATH=enp26s0f0
E: ID_NET_NAME_MAC=enx3cecefd0da35
E: ID_NET_NAME_ONBOARD=eno2
E: ID_NET_NAME_PATH=enp26s0f1
E: ID_NET_NAME_MAC=enx3cfdfeb49d30
E: ID_NET_NAME_PATH=enp94s0f0
E: ID_NET_NAME_MAC=enx3cfdfeb49d31
E: ID_NET_NAME_PATH=enp94s0f1
# dmesg | grep -F "renamed from"
[ 32.323995] i40e 0000:1a:00.0 eno1: renamed from eth0
[ 32.631978] i40e 0000:1a:00.1 eno2: renamed from eth1
[ 32.891945] i40e 0000:5e:00.0 enp94s0f0: renamed from eth2
[ 33.151972] i40e 0000:5e:00.1 enp94s0f1: renamed from eth3
and after a reboot into the bpo kernel:
# cat /etc/debian_version
12.10
# uname -vr
6.12.22+bpo-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.22-1~bpo12+1 (2025-04-25) # ip l show | grep -F " en" | cut -d: -f2
eno1np0
altname enp26s0f0np0
eno2np1
altname enp26s0f1np1
enp94s0f0np0
enp94s0f1np1
# udevadm info -e | grep -F ID_NET_NAMING_SCHEME= | sort -u
E: ID_NET_NAMING_SCHEME=v252
# udevadm info -e | grep -F ID_NET_NAME_
E: ID_NET_NAME_MAC=enx3cecefd0da34
E: ID_NET_NAME_ONBOARD=eno1np0
E: ID_NET_NAME_PATH=enp26s0f0np0
E: ID_NET_NAME_MAC=enx3cecefd0da35
E: ID_NET_NAME_ONBOARD=eno2np1
E: ID_NET_NAME_PATH=enp26s0f1np1
E: ID_NET_NAME_MAC=enx3cfdfeb49d30
E: ID_NET_NAME_PATH=enp94s0f0np0
E: ID_NET_NAME_MAC=enx3cfdfeb49d31
E: ID_NET_NAME_PATH=enp94s0f1np1
# dmesg | grep -F "renamed from"
[ 31.392947] i40e 0000:1a:00.1 eno2np1: renamed from eth1
[ 31.398904] i40e 0000:1a:00.0 eno1np0: renamed from eth0
[ 31.405096] i40e 0000:5e:00.0 enp94s0f0np0: renamed from eth2
[ 31.411265] i40e 0000:5e:00.1 enp94s0f1np1: renamed from eth3
please let me know if there is any additional information that would be
helpful or if you have insight into this. seems like it's either a bug
that should be reported or a change that i'll need to adapt to (and
perhaps documented in "Issues to be aware of for trixie"). also please
let me know if there's a better forum/mailing list to bring this
question up in.
thanks in advance!
andy
1.
https://serverfault.com/a/1143604
2.
https://forum.proxmox.com/threads/the-joys-of-spontaneous-network-interface-renaming.153817/post-699537
3.
https://www.mail-archive.com/linux-fai@uni-koeln.de/msg08299.html
4.
https://www.freedesktop.org/software/systemd/man/latest/systemd.net-naming-scheme.html
--
andrew bezella <
abezella@archive.org>
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