IPV6 is the most recent version of internet protocol (IP) designed to eliminate the long-anticipated address exhaustion problem of IPV4. In order to disable IPV6 on Linux/Ubuntu, please follow the steps below:
1 Open Terminal
2 Enter gksudo gedit /etc/sysctl.conf and open the configuration file and add the following lines at the end
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1