Howto disable Consistent Network Device Naming

RHEL 7 (and CentOS 7) introduced the concept of Consistent Network Device Naming. In practice this means that an old network device name like eth0 would change into something enp0s25. Should it not be obvious how those funky new network device names are generated then read SystemD: Understanding Predictable Network Interface Names

Here are the steps to disable Consistent Network Device Naming on RHEL 7 or CentOS 7:

Step 1) add kernel boot args & regenerate the grub config

The following kernel boot arguments need to be added:
biosdevname=0
net.ifnames=0

Open /etc/default/grub with your favorite editor and add those two options to the line starting with GRUB_CMDLINE_LINUX:

Now let’s regenerate the grub config with the following command:

[root@test ~]# grub2-mkconfig -o /boot/grub2/grub.cfg

And you should see output like this:

Step 2) add a udev symlink, just to make sure

Basically adding the biosdevname=0 and net.ifnames=0 arguments to grub should be enough. But here’s another way just in case:

[root@test ~]# ln -s /dev/null /etc/udev/rules.d/80-net-name-slot.rules

After rebooting the host, the old familiar network ethX devices should be back.