How To Disable IPv6 On a Linux Computer?

Last modified: March 26, 2019

This guide will show you how to disable IPv6 on a Linux computer and also provide answers to some frequently asked questions (FAQ).

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What is IPv6?

IPv6 is an Internet Protocol Version 6 and it was designed to replace IPv4 which is the current Internet protocol and still widely used.

Do you support IPv6?

At the moment we do not support IPv6 VPN tunnels. Most of our data centres and Internet Service Providers do not assign public IPv6 addresses. However, we will be supporting IPv6 when it’s necessary in the future.

Why do I need to disable IPv6?

Our VPN service works over IPv4. Your IPv6 traffic may leak if your network supports IPv6 and it’s enabled on your computer.

How can I do a quick check to see if IPv6 is enabled on my network?

Go to our IP checker site and check on your IPv6 capability.  If there is a red X sign, you’re good.

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Now that you’ve read and understood about IPv6, please follow the steps below to disable IPv6 on your Linux computer via command line.

Note: Whilst these instructions are created based on Ubuntu distribution, the principle should apply to all Debian based systems.

STEP 1: Editing sysctl.conf file

Launch Terminal app and enter the command below. You may need to enter your computer’s administrative password.

sudo gedit /etc/sysctl.conf

Once you have configuration file opened, add the following lines at the end.

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

Once you’ve entered the lines above, click on Save at the top right.

STEP 2: Checking on IPv6 status

Run the command below in the Terminal app.

cat /proc/sys/net/ipv6/conf/all/disable_ipv6

If it reports “1”, it means you have disabled IPV6. If it reports “0”, follow the steps below:

At the Terminal, type in the command below:

sudo sysctl -p

You should now see the lines below:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

Now, just repeat Step 2 to check on your IPv6 status and it should report “1” which means IPv6 has been disabled on your computer.

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