Change default network interface name on Ubuntu

If you ever interested in changing interface names to old type ethX, here is the tutorial for you. As you can see in the following command, my system is having a network adapter called ens33.

This is just the case of VMware environment, it may vary depends on the hardware but the steps to get back ethX will be the same.

$ ip a
1: lo: <loopback,up,lower_up> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: </loopback,up,lower_up>ens33: <broadcast,multicast,up,lower_up> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:05:a3:e2 brd ff:ff:ff:ff:ff:ff
    </broadcast,multicast,up,lower_up>inet 192.168.12.12/24 brd 192.168.12.255 scope global dynamic ens33
       valid_lft 1683sec preferred_lft 1683sec
    inet6 fe80::20c:29ff:fe05:a3e2/64 scope link
       valid_lft forever preferred_lft forever

From the dmesg command, you can see that the device got renamed during the system boot.

$ dmesg | grep -i eth
[    3.050064] e1000 0000:02:01.0 eth0: (PCI:66MHz:32-bit) 00:0c:29:05:a3:e2
[    3.050074] e1000 0000:02:01.0 eth0: Intel(R) PRO/1000 Network Connection
[    3.057410] e1000 0000:02:01.0 ens33: renamed from eth0

To get an ethX back, edit the grub file.

sudo vim /etc/default/grub

Look for GRUB_CMDLINE_LINUX and add the following net.ifnames=0 biosdevname=0.

From:

GRUB_CMDLINE_LINUX=""

To:

GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0"

Generate a new grub file using the following command.

$ sudo grub-mkconfig -o /boot/grub/grub.cfg
Generating grub configuration file ...
Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported.
Found linux image: /boot/vmlinuz-4.4.0-15-generic
Found initrd image: /boot/initrd.img-4.4.0-15-generic
Found memtest86+ image: /memtest86+.elf
Found memtest86+ image: /memtest86+.bin
done

Reboot your system.

sudo reboot

After the system reboot, just check whether you have an ethX back.

$ ip a
1: lo: <loopback,up,lower_up> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: </loopback,up,lower_up>eth0: <broadcast,multicast,up,lower_up> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:05:a3:e2 brd ff:ff:ff:ff:ff:ff
    </broadcast,multicast,up,lower_up>inet 192.168.12.12/24 brd 192.168.12.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe05:a3e2/64 scope link
       valid_lft forever preferred_lft forever