on Red Hat based systems:
$ sudo sysctl -w net.ipv6.conf.all.disable_ipv6=1 $ sudo sysctl -w net.ipv6.conf.default.disable_ipv6=1
to enable it again:
$ sudo sysctl -w net.ipv6.conf.all.disable_ipv6=0 $ sudo sysctl -w net.ipv6.conf.default.disable_ipv6=0
on Debian based systems:
sudo vi /etc/sysctl.conf
Add these lines:
net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.disable_ipv6 = 1
restart the system.