Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm running Debian Squeeze (with a stock 2.6.32 kernel). I'd like to completely disable any kind of IPv6 traffic. Can I do this? There doesn't seem to be any relevant module loaded. Perhaps some setting in /sys or /proc?

I read this, but my /etc/modprobe.d/aliases doesn't have a

alias net-pf-10 ipv6

line, it's commented-out already.

share|improve this question
That's not IPv6 traffic. SRC= DST= – Michael Hampton Mar 9 '13 at 3:49
@MichaelHampton: You're right. But the question is still generally relevant. – einpoklum Mar 10 '13 at 5:10
In that case, I will have to remind future readers that disabling IPv6 is generally a really bad idea, and should not be done except as a last resort, as it will cause you problems later when you have to use IPv6. – Michael Hampton Mar 10 '13 at 5:16
@MichaelHampton It's a simple process to re-enable it, assumng you remember. I disabled it as a quick fix (I've since changed the preference properly) on openSUSE a while ago, because it preferred IPv6 which would take a while to time out - giving me a not-so-nice several second delay on every request... But, yea, there's almost alwys a better way than flat out disabling it. – Bob Mar 10 '13 at 5:21
FYI: A working solution is at – Tino May 29 '14 at 7:51
up vote 3 down vote accepted

You can find the answer in Debian's Wiki:

# echo net.ipv6.conf.all.disable_ipv6=1 > /etc/sysctl.d/disableipv6.conf

But be aware that this disables IPv6 globally, so anything that needs it wont work properly.

share|improve this answer
Note that you need to restart your computer for this to be applied, but you probably already knew that. – 1ace Mar 9 '13 at 0:22
To avoid a restart, you can load the configuration file with sysctl -p /etc/sysctl.d/disableipv6.conf (I'm not too sure about this - I normally only use it on /etc/sysctl.conf) or directly set the value (non-persistent) with echo 1 > /proc/sys/net/ipv6/conf/all/disable_ipv6 or sysctl -w net.ipv6.conf.all.disable_ipv6=1 – Bob Mar 10 '13 at 5:18
With Kernel 3.2.x this does not completely disable IPv6. It only disables IPv6 Kernel autoconfiguration. The IPv6 interface then is unconfigured and can induce major problems in IPv4-only-boxes. – Tino May 29 '14 at 7:26

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.