IPv6

Disabling IPv6

In Ubuntu, IPv6 can be disabled in /etc/sysctl.conf

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

Apparently, Hadoop needs IPv6 to be IPv6

sa: http://askubuntu.com/questions/440649/how-to-disable-ipv6-in-ubuntu-14-04[How to disable IPv6 in Ubuntu 14.04?]