[systemd-devel] systemd link file rename eth0 do not take effect

Tue Jun 17 06:20:02 UTC 2025

nfsroot= causes the interface to be brought up very early, before udev 
starts, and before it has a chance to apply its rules and .link files.

Before kernel 6.2, it was not possible to rename interfaces that were 
already "up" (see linux commit bd039b5ea2a91).

On another note, even though NamePolicy doesn't provide any names in 
your case, you should still clear it in general:

[Link]

NamePolicy=

Name=mycustometh

On 17/06/2025 08.59, He, Guocai (CN) wrote:
>
> Hi,
>
> I want to create a link file and want to match the mac to rename eth0 
> to mycustometh but fail.
> seems that the link file is not applied?
> The fllowing is my step and some logs:
>
> #1 etho mac
> udevadm info /sys/class/net/eth0
>    E: ID_NET_NAME_MAC=enxa4bf016bfaf5
>
> #2 link file
> root at intel-x86-64:~# cat /etc/systemd/network/00-eth0.link
> [Match]
> MACAddress=a4:bf:01:6b:fa:f5
>
> [Link]
> Name=mycustometh
>
> #3 only one link file
> root at intel-x86-64:~# ls /etc/systemd/network/
> 00-eth0.link
>
> #4 the link file in /lib/systemd/network/  I try to remove 
> 99-default.link, it still not work
> root at intel-x86-64:/lib/systemd/network# ls
> 80-6rd-tunnel.network       80-container-ve.network 
> 80-wifi-adhoc.network            80-wired.network
> 80-container-host0.network  80-container-vz.network 
> 80-wifi-ap.network.example       99-default.link
> 80-container-vb.network     80-vm-vt.network 
> 80-wifi-station.network.example
> root at intel-x86-64:/lib/systemd/network# cat 99-default.link
> [Match]
> OriginalName=*
>
> [Link]
> NamePolicy=keep kernel database onboard slot path
> AlternativeNamesPolicy=database onboard slot path
> MACAddressPolicy=persistent
>
> #5 test the changes
> root at intel-x86-64:~# udevadm test-builtin net_setup_link 
> /sys/class/net/eth0
> Trying to open "/etc/systemd/hwdb/hwdb.bin"...
> Trying to open "/etc/udev/hwdb.bin"...
> Trying to open "/usr/lib/systemd/hwdb/hwdb.bin"...
> Trying to open "/lib/systemd/hwdb/hwdb.bin"...
> Trying to open "/lib/udev/hwdb.bin"...
> === trie on-disk ===
> tool version:          250
> file size:         9764936 bytes
> header size             80 bytes
> strings            2429280 bytes
> nodes              7335576 bytes
> Load module index
> Found cgroup2 on /sys/fs/cgroup/unified, unified hierarchy for systemd 
> controller
> Found container virtualization none.
> Loaded timestamp for '/etc/systemd/network'.
> Parsed configuration file /etc/systemd/network/00-eth0.link
> Created link configuration context.
> eth0: Device has name_assign_type=1
> eth0: Device has addr_assign_type=0
> ID_NET_DRIVER=igb
> eth0: Config file /etc/systemd/network/00-eth0.link is applied
> eth0: Using static MAC address.
> eth0: Policies didn't yield a name, using specified Name=mycustometh.
> ID_NET_LINK_FILE=/etc/systemd/network/00-eth0.link
> ID_NET_NAME=mycustometh
> Unload module index
> Unloaded link configuration context.
>
> #6 reboot and the eth0 is not changed
> root at intel-x86-64:/# ip link
> 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP 
> mode DEFAULT group default qlen 1000
>     link/ether a4:bf:01:6b:fa:f5 brd ff:ff:ff:ff:ff:ff
>
> #7 boot cmdline
> root at intel-x86-64:~# cat /proc/cmdline
> kernel console=ttyS4,115200 root=/dev/sda1 
> nfsroot=128.224.165.20:/export/pxeboot/vlm-boards/29170/rootfs,v3,tcp 
> rw selinux=0 udev.log_priority=debug enforcing=0 intel_iommu=on 
> iommu=pt no_console_suspend ignore_loglevel
>
> #8 logs after reboot, can not see such as "00-eth0.link is applied"
> journalctl -u systemd-udevd
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Trying to open 
> "/etc/udev/hwdb.bin"...
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Trying to open 
> "/usr/lib/systemd/hwdb/hwdb.bin"...
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Trying to open 
> "/lib/systemd/hwdb/hwdb.bin"...
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Trying to open 
> "/lib/udev/hwdb.bin"...
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: === trie on-disk ===
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: tool 
> version:          250
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: file size:         
> 9764936 bytes
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: header 
> size             80 bytes
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: strings            
> 2429280 bytes
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: nodes              
> 7335576 bytes
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Load module index
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Loaded timestamp for 
> '/etc/systemd/network'.
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Parsed configuration 
> file /etc/systemd/network/00-eth0.link
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Created link 
> configuration context.
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Loaded timestamp for 
> '/etc/udev/rules.d'.
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Loaded timestamp for 
> '/lib/udev/rules.d'.
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Skipping overridden 
> file '/lib/udev/rules.d/80-net-setup-link.rules'.
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Reading rules file: 
> /lib/udev/rules.d/01-md-raid-creating.rules
> Jun 17 02:46:02 intel-x86-64 systemd-udevd[252]: Reading rules file: 
> /lib/udev/rules.d/10-dm.rules
> ..................
>
> Anybody have meet the same issue? who can help to have a look at this 
> issue?
>
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