How to Disable IPv6 on Ubuntu Linux

You disable IPv6 on Ubuntu Linux by editing its network configuration settings.

IPv6 is the latest version of the Internet Protocol, designed to provide a massive number of unique IP addresses, succeeding the older IPv4 system. Most modern operating systems, including Ubuntu Linux, enable it by default.

You might want to disable IPv6 on your Ubuntu 22.04 LTS system if you’re experiencing network compatibility issues with older hardware or specific applications.

Following these steps will help you turn off IPv6, potentially resolving connectivity problems and ensuring your system uses the most compatible network protocol for your environment.

Disable IPv6

There are multiple ways to disable IPv6 on Ubuntu. However, the simplest way is to disable it in the [/etc/sysctl.conf] file.

Run the command below to disable IPv6.

sudo bash
echo "net.ipv6.conf.all.disable_ipv6 = 1" >> /etc/sysctl.conf

Next, apply your changes by running the command below.

sudo sysctl -p

Display your IP address details.

ip address show

The output should show that IPv6 is no longer usable on the machine.

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:bc:b2:46 brd ff:ff:ff:ff:ff:ff
    altname enp2s1
    inet 192.168.156.130/24 brd 192.168.156.255 scope global dynamic noprefixroute ens33
       valid_lft 1716sec preferred_lft 1716sec

That should do it!

Conclusion:

• Disabling IPv6 on Ubuntu Linux can enhance compatibility with older applications and network infrastructures that do not support it.
• This process is straightforward and can be accomplished with a few simple commands.
• Users can easily revert the changes if they decide to enable IPv6.
• Verifying the IP address details is essential to ensure that IPv6 is effectively disabled.
• Always back up configuration files before making changes to prevent unintended network issues.