How to disable IPv6 on Ubuntu?
This worked for me:
Add these lines to the bottom of sysctl.conf
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
Then run sudo sysctl -p
or reboot
source: http://www.noobslab.com/2012/05/disable-ipv6-if-your-internet-is.html
This of course won't stop bind from blindly trying to use ipv6 though, so you also need to alter /etc/default/bind9
like so:
# run resolvconf?
RESOLVCONF=yes
# startup options for the server
OPTIONS="-4 -u bind"
source: http://blog.evilcoder.net/disable-ipv6-on-bind9-linux/#sthash.U95y4s6U.dpuf
To check if IPv6 is enabled or disabled, from a terminal window:
$ cat /proc/sys/net/ipv6/conf/all/disable_ipv6
0 means it’s enabled and 1 is disabled.
To disable IPv6
$ sudo su -
# nano /etc/sysctl.conf
and add these lines to sysctl.conf file
#disable ipv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
Save sysctl.conf file with new config, then reboot your system
# reboot
Check your system again
$ cat /proc/sys/net/ipv6/conf/all/disable_ipv6
Now you should see “1″ means IPv6 has been disabled on your system.
From http://namhuy.net/1419/disable-ipv6-ubuntu-linux-mint.html