This grump will disable IPv6 on all network interfaces. It has only been tested on Mac OSx Sierra. It will prompt for password entry on every network interface. Inspired by this article. Many vpn clients don't currently support IPv6 and will leak your IPv6.
If grump has not yet been installed, you can do so using:
npm i -g grumpExample usage:
grump disableIPv6
see grumpJS.com to find other useful grumps!