• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer navigation

The Geek Diary

  • OS
    • Linux
    • CentOS/RHEL
    • VCS
  • Interview Questions
  • Database
    • MariaDB
  • DevOps
    • Docker
    • Shell Scripting
  • Big Data
    • Hadoop
    • Cloudera
    • Hortonworks HDP

How to Disable IPv6 on Ubuntu 22.04 LTS Jammy Jellyfish

by admin

Internet Protocol version 6 (IPv6) is a 128-bit number identifying an endpoint in a TCP/IP communication. This means that with IPv6 we can assign on the order of 1038 individual machines (devices). In contrast to IPv4, IPv6 uses a hexadecimal representation, eight groups of 16 bits each, separating the groups by a colon (:).

Ubuntu 22.04 LTS Jammy Jellyfish enables Internet Protocol Version 6 (IPv6) by default. However, in certain situations, some users may find it desirable to disable IPv6 support or to re-enable it after it has been disabled.

Disabling IPv6 support (Permanently)

Disable ipv6 built-in kernel module.

1. Edit /etc/default/grub and append ipv6.disable=1 to GRUB_CMDLINE_LINUX and GRUB_CMDLINE_LINUX_DEFAULT like the following sample:

FROM:

GRUB_CMDLINE_LINUX_DEFAULT=""
GRUB_CMDLINE_LINUX=""

TO:

GRUB_CMDLINE_LINUX_DEFAULT="ipv6.disable=1"
GRUB_CMDLINE_LINUX="ipv6.disable=1"

2. Run the update-grub command to regenerate the grub.cfg file:

# update-grub

3. Reboot the system to disable IPv6 support.

Disabling IPv6 via sysctl settings

Alternatively, this can be done via sysctl settings.

1. To disable Ipv6 temporarily on the system apply the below sysctl settings:

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

2. In order to make the above sysctl changes permanent, we need to add them to /etc/sysctl.conf confirguation file.

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

3. Use “sysctl -p” to apply the changes from /etc/sysctl.conf file.

# sysctl -p

4. An output of 1 from the below command verifies that the IPv6 has been successfully disabled.

# cat /proc/sys/net/ipv6/conf/all/disable_ipv6
1

Re-enabling IPv6 support

1. Edit /etc/default/grub and delete the entry ipv6.disable=1 from the GRUB_CMDLINE_LINUX and GRUB_CMDLINE_LINUX_DEFAULT, like the following sample:

FROM:

GRUB_CMDLINE_LINUX_DEFAULT="ipv6.disable=1"
GRUB_CMDLINE_LINUX="ipv6.disable=1"

TO:

GRUB_CMDLINE_LINUX_DEFAULT=""
GRUB_CMDLINE_LINUX=""

2. Run the “update-grub” command to regenerate the grub.cfg file.

# update-grub

3. Delete the below entries from /etc/sysctl.conf file:

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

4. Use “sysctl -p” to apply the changes from /etc/sysctl.conf file.

# sysctl -p

5. Reboot the system if required.

Filed Under: Linux, Ubuntu

Some more articles you might also be interested in …

  1. gdal_translate: Convert raster data between different formats
  2. urxvt Command Examples in Linux
  3. binwalk: command not found
  4. who Command Examples in Linux
  5. CentOS / RHEL 5 : How to disable device mapper multipath (dm-multipath)
  6. fastmod: A fast partial replacement for the codemod tool, replace and replace all in the whole codebase
  7. How to uninstall scons package from Ubuntu
  8. CentOS / RHEL : DNS servers in /etc/resolv.conf change after a reboot/network service restart. How to make them permanent
  9. atoum: A simple, modern and intuitive unit testing framework for PHP (Command Examples)
  10. dpkg Command Examples in Linux

You May Also Like

Primary Sidebar

Recent Posts

  • Vanilla OS 2 Released: A New Era for Linux Enthusiasts
  • mk Command Examples
  • mixxx Command Examples
  • mix Command Examples

© 2025 · The Geek Diary

  • Archives
  • Contact Us
  • Copyright