Debian Disable IPv6 - Shell/Bash

In this guide, we will discuss how to disable IPv6 on a Debian-based system using shell/bash commands. IPv6 is the next generation Internet Protocol, but sometimes it is necessary to disable it due to various reasons like network compatibility issues or security concerns.

Note: Please ensure that you have administrative privileges or sudo access before executing the following commands.

Checking IPv6 Status

Before disabling IPv6, you may want to check the current status of IPv6 on your Debian system. Open a terminal and execute the following command:

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

If the output is 0, it means that IPv6 is enabled. If the output is 1, it means that IPv6 is already disabled.

Temporary Method

To temporarily disable IPv6, you can use the sysctl command. Open a terminal and execute the following commands:

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

These commands modify the kernel parameters net.ipv6.conf.all.disable_ipv6 and net.ipv6.conf.default.disable_ipv6 to 1, which effectively disables IPv6. However, this change will not persist across reboots.

Permanent Method

To permanently disable IPv6, you need to make changes to the system configuration files. Here's how you can do it:

1. Open the /etc/sysctl.conf configuration file in a text editor with administrative privileges.

$ sudo nano /etc/sysctl.conf

2. Add the following lines at the end of the file:

# Disable IPv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1

3. Save the file and exit the text editor.

4. To apply the changes, execute the following command:

$ sudo sysctl -p

This command reloads the sysctl configuration, applying the changes made in /etc/sysctl.conf.

Verifying Changes

After applying the changes, you can again check the status of IPv6 using the command mentioned earlier:

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

If the output is 1, it means that IPv6 has been successfully disabled.

Conclusion

Disabling IPv6 on a Debian-based system can be done temporarily using the sysctl command, or permanently by modifying system configuration files. Choose the method that best suits your requirements, but keep in mind that disabling IPv6 may have implications on network compatibility and future technological advancements.