How-To disable IPv6 on RHEL6 / CentOS 6 / etc

Proper way of disabling IPv6 subsytem in RedHat Linux 6 / CentOS 6 (dont unload modules or so)

in /etc/sysctl.conf  :  net.ipv6.conf.all.disable_ipv6 = 1

in /etc/sysconfig/network  : NETWORKING_IPV6=no

in /etc/sysconfig/network-scripts/ifcfg-eth0 : IPV6INIT=”no”

disable iptables6 – chkconfig –level 345 ip6tables off

reboot

or

echo “net.ipv6.conf.default.disable_ipv6=1″ >> /etc/sysctl.conf
echo “net.ipv6.conf.all.disable_ipv6 = 1″ >> /etc/sysctl.conf

then run the following command

sysctl -p

no reboot is required note the space before and after the =

if you want to test the config on the fly without editing the sysctl.conf file execute the following commands

sysctl -w net.ipv6.conf.default.disable_ipv6=1
sysctl -w net.ipv6.conf.all.disable_ipv6=1