Prevent Predictable Interface Names

[theAkito]

Creating a bug report/issue

Required Information

• DietPi version | cat /boot/dietpi/.version
  v6.30.0 (before my fix)
  v6.31.2 (after my fix)
• Distro version | echo $G_DISTRO_NAME or cat /etc/debian_version
  Debian Bullseye
• Kernel version | uname -a
  Linux hostname 4.19.66-v7+ DietPi-Config | CPU performance benchmark #1253 SMP Thu Aug 15 11:49:46 BST 2019 armv7l GNU/Linux
• SBC model | echo $G_HW_MODEL_NAME or (EG: RPi3)
  Raspberry Pi 3 B
• Power supply used | (EG: 5V 1A RAVpower)
  Custom
• SDcard used | (EG: SanDisk ultra)
  Transcend 32GB

Steps to reproduce

1. Replace repository sources with newer ones.
2. full-upgrade from Buster to Bullseye.

Expected behaviour

1. Ethernet's interface name should remain eth0.

Actual behaviour

1. See that ln -s /dev/null /etc/systemd/network/99-default.link is already set.
2. eth0 is still renamed to enxMAC_ADDRESS without user's consent.

Extra details

• I fixed it by appending net.ifnames=0 to /boot/cmdline.txt.
• I've already done the upgrade from Buster to Bullseye many times. Never had this issue before. Don't know why it happened now.

[MichaIng]

Many thanks for your report.

Yes I recognised it as well and new images since DietPi v6.27 contain all related configs to assure predictable names: 017aa0b

With this /etc/systemd/network/99-default.link might not be required anymore when the cmdline option and/or the udev rule are set, but AFAIK it as well assures that systemd-networkd is not configuring anything if enabled/started by accident or some software package, which would collide with ifupdown.