4 ms·

I would have thought it would work the other way? Surely ISPs will have difficulty switching off v4 access to consumers, because of all the old v4 devices out t

by ajb 9y ago

I would have thought it would work the other way? Surely ISPs will have difficulty switching off v4 access to consumers, because of all the old v4 devices out there. But at some point soon the vast majority of servers will support v6, a which point some big ISP will say 'we will no longer support v4-only servers after date X, we will NAT to v6 for comsumer devices if you want to talk to our customers you need v6'. Some time after that IPv4 will effectively no longer be a global protocol.

azernik 9y ago
The IPv6 shutoff is for clients first because NAT is a solution only for v6 client to v4 server; the way it works is you send packets to an IPv6 address that has an IPv4 address stuffed into 4 convenient bytes, and the NAT gateway installs a mapping for that communication. This doesn't work the other way around, because there's no way to address the IPv6 internet endpoints in an IPv4 packet to set up that initial mapping. Generally the limitation is more about infrastructure (including private in-home routers) than about endpoint devices; Windows, OSX, iOS, Android, and Linux have all supported IPv6 for years.
phil21 9y ago
You have the technical answer, but I think the more useful answer is human based. Content providers will stay dual stack basically indefinitely - abslutely no website operator wants to lose even 1% of their traffic due to a technical limitation, so I do not expect demand for v4-enabled websites to die off any time soon. I would expect 95%+ v6 usage before you even see this being a thing commercially, and even at those numbers only very small marginal operations will go v6 only. The consumers and consumer ISPs have both a better technical solution, as well as no consumer ISP gives a shit if their customers can't access 2% of the internet. Therefore the change due to both technical reasons and simple game theory must come from the "eyeballs" side of the equation.

by ajb 9y ago

azernik 9y ago

The IPv6 shutoff is for clients first because NAT is a solution only for v6 client to v4 server; the way it works is you send packets to an IPv6 address that has an IPv4 address stuffed into 4 convenient bytes, and the NAT gateway installs a mapping for that communication. This doesn't work the other way around, because there's no way to address the IPv6 internet endpoints in an IPv4 packet to set up that initial mapping. Generally the limitation is more about infrastructure (including private in-home routers) than about endpoint devices; Windows, OSX, iOS, Android, and Linux have all supported IPv6 for years.

phil21 9y ago

You have the technical answer, but I think the more useful answer is human based. Content providers will stay dual stack basically indefinitely - abslutely no website operator wants to lose even 1% of their traffic due to a technical limitation, so I do not expect demand for v4-enabled websites to die off any time soon. I would expect 95%+ v6 usage before you even see this being a thing commercially, and even at those numbers only very small marginal operations will go v6 only. The consumers and consumer ISPs have both a better technical solution, as well as no consumer ISP gives a shit if their customers can't access 2% of the internet. Therefore the change due to both technical reasons and simple game theory must come from the "eyeballs" side of the equation.