Das Werkstatt

Posted: **Thu Aug 21, 2014 4:40 pm**

For internal network computers, I disable IPv6 in most cases.

This here is basically just a copy of the "How to turn off IPv6" section on the Debian Wiki:

1) Edit /etc/sysctl.conf
and add the following parameters to kernel:

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

Note: This disables IPv6 on all network interfaces.
Optional: If you want to only disable it on specific ones, you can use a syntax like this:

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net.ipv6.conf.eth0.disable_ipv6 = 1

(This would apply only to "eth0" for example)

2) Apply changes:
After editing sysctl.conf, you should run sysctl -p to activate changes or reboot system.

That's it.

Posted: **Sun Mar 29, 2020 5:26 pm**

Another option that I now find slightly cleaner than modifying "/etc/sysctl.conf" directly, is to use the "/etc/sysctl.d" folder to keep this config separately (and easier to enable/disable it).

1) Create a file called "/etc/sysctl.d/70-disable-ipv6.conf"

2) Put the same lines in that file as you would into sysctl.conf directly

3) Save it and either reboot or reload sysctl:

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$ sysctl -p -f /etc/sysctl.d/70-disable-ipv6.conf

Feels cleaner

Posted: **Sun Jul 26, 2020 4:28 pm**

Here are some nice links with information about IPv6:

Das Werkstatt

Debian: Disable IPv6

Debian: Disable IPv6

IPv6: use "/etc/sysctl.d"

Useful IPv6 information