Disable IPv6 Networking Support Automatic Loading
To disable support for ('ipv6') add the following line to
'/etc/sysctl.d/ipv6.conf' (or another file in
'/etc/sysctl.d'):
'net.ipv6.conf.all.disable_ipv6 = 1'
This disables IPv6 on all network interfaces as other services and system
functionality require the IPv6 stack loaded to work.