How to disable ipv6 in Ubuntu Linux

IPV6 got many new exciting features but if you are not on an IPV6 network, I don't think there is any benefit to having this protocol enabled.

First, check if IPv6 is enabled by running the following command. If the output is 0, it means its enabled. If it’s 1, then its disabled already.

cat /proc/sys/net/ipv6/conf/all/disable_ipv6

So, to disable ivp6 you need to add the following entries into your /etc/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

Moreover it's also a good idea to disable loading of ivp6 module into kernel durning booting, to disable the ivp6 module you need to add following entry into your /etc/modprobe.d/blacklist.conf file

# Disable IPV6
blacklist ipv6