In order to disable the ipv6 in Ubuntu for many reasons like installing hadoop
- open the terminal and write following command
- sudo gedit /etc/sysctl.conf
- once the editor is opened copy the following lines
# disable ipv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
Once that is copied , either you can restart sysctl or restart in somecase when the instructions does not make any change
