[openasocket]

Might be a dumb question, but why would you want or need more than one IP address for an instance? It's not like more addresses will let you download/upload things faster. Maybe if you want to run multiple web servers on port 80 and give each one a different IP address, but how often do people do that, especially more than 8 times over?

[derefr]

Picture running something like Docker on a box, where each container gets its own IPv6 address—with services on their proper ports—instead of mashing a bunch of NATed ports together under the host's IP.

Or, moreover (and this is a bit of a pipe-dream, but it's something I've been hacking on to make possible) picture running something like an Erlang node on a box, where each Erlang process gets its own IPv6 address, fully Internet-routable. This effectively makes Erlang into an SDN vswitch for ephemeral, featherweight virtual machines (which would be oddly similar to AWS's just-announced "Lambda@Edge".)

[auganov]

Quantity changes the quality here. IPv6 address space being so large, we can afford to give everyone a virtually infinite number of addresses. Which in turn enables everything to be globally routable. I never cared about IPv6 much. Once I grasped it I am actually so so excited about it.

[rajivm]

When you're running services in containers on the machine and want to have them be directly networkable without another overlay network.

[kstrauser]

You'd more likely want them for outbound connections. On modern OSes, the IPv6 stack periodically calculates a new IP (see https://tools.ietf.org/html/rfc4941). Think of it as a kind of one-time-use address, so remote machines can't say "hey, I got a download request from this IP last week. I should try to hack it today!"

[meddlepal]

Containers. IP per container.