How To Disable IPv6 on Linux/Ubuntu?

If you are looking to temporarily disable the IPV6 of your Ubuntu 20.4 device then you can execute the following commands into the terminal.

$ sudo sysctl -w net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.all.disable_ipv6 = 1
$ sudo sysctl -w net.ipv6.conf.default.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6 = 1

The above commands will temporarily disable IPv6, meaning that the settings will not persist after reboot. To re-enable IPv6 reboot your system or execute the above commands again, however reverse the logic and change 1 to 0.

Incase if you are looking to permenantly disable the IPV6 on your device. Then you can follow the steps provided below 👇

Before you start, open a command line terminal and use nano or your preferred text editor to open the GRUB configuration file with root permissions.

Command:
$ sudo nano /etc/default/grub

Next, change the following line. If your line already has some boot parameters configured such as splash or quiet, just append your change after them.

FROM: GRUB_CMDLINE_LINUX_DEFAULT=””
TO: GRUB_CMDLINE_LINUX_DEFAULT=”ipv6.disable=1″

After you have made that change to the file, save the changes and exit. Then, execute the following command to update GRUB.

Command:
$ sudo update-grub