Ubuntu's ppa domain - ppa.launchpad.net - and the domain their normal repos are hosted on - archive.ubuntu.com and security.ubuntu.com support IPv6. You can tes

Ubuntu's ppa domain - ppa.launchpad.net - and the domain their normal repos are hosted on - archive.ubuntu.com and security.ubuntu.com support IPv6. You can test it with this tool: https://ipv6-test.com/validate.php https://ipv6-test.com/validate.php It's common for hosting providers to modify system images to point at a nearer mirror or even a local one they own. Perhaps it wasn't working on your system because of some change you or the host made.