Disable IPv6 in Ubuntu 8.04

Some may find that out-of-the-box, Hardy Heron’s network performance is painfully slow. By default, IPv6 is enabled, and chances are good that your nearest router can’t speak the language nor interpret DNS requests efficiently.

To disable IPv6, open a shell and append the following to /etc/modprobe.d/blacklist:

# disable ipv6
blacklist ipv6


To verify that IPv6 is disabled, run

lsmod | grep ipv6


ip a | grep inet6

The commands shouldn’t return any information. Firefox browsing speeds should be much improved.

About Benjamin Perove

Ben has been associated with a broad spectrum of technologies starting from an early age, and he's contributed to the success of many businesses and enterprises professionally since 2001. Most of his time is spent building cool stuff. When he's not working, he enjoys reading, playing acoustic guitar, and being with friends. He currently resides in Medellin, Colombia.

  • Corey

    It works!

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  • http://pullingthingsapart.com Graham S.

    A lot easier than I thought it would be, thanks!

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  • MIke S

    Which blacklist file, I have the following:


  • dogafin

    i couldnt edit blacklist file, and cant run nautilus, any way to change permission on the file?

  • http://benperove.com/ Ben

    Mike S,

    In newer versions of Ubuntu, the file you need to modify is blacklist.conf.


    Give this a shot:

    sudo gedit /etc/modprobe.d/blacklist

    Enter your super user password and you should see the file open. If you don’t know the password, type:

    sudo passwd root

    Enter the new password twice, then try to open the blacklist file.

  • Max Wyatt

    Using /etc/modprobe.d/blacklist.conf to disable ipv6 doesn’t work on 9.10. Furthermore, IPv6 doesn’t seem to be loaded as a module at all. I an only assume it’s built into the Kernel. I use Linux so I can control my environment rather than having it handed to me, I don’t like this at all.

  • http://benperove.com/ Ben

    Hey Max, last I checked the title said 8.04, not 9.10. Sorry I haven’t updated lately.

    To disable in 9.10, modify /etc/modprobe.d/aliases:

    alias net-pf-10 off ipv6

    Save, reboot.

    Thx for the comment.

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