On Mon, Jun 15, 2026 at 11:33 PM Saku Ytti via NANOG <[email protected]> wrote: > I don't see any future where organically IPv4 dies
I do. First, service providers get fully on board with native Ipv6. Once a customer deploys IPv6 at all, they want it from all their providers so that their users' software isn't using second-class connectivity. However slow the IPv6 customer deployments, it eventually passes a threshold where the disincentive to stay IPv4-only as a service provider can't be ignored. Meanwhile, smaller and newer ISPs have an IPv4 acquisition problem. They can solve that problem with CGNAT, but if they've deployed IPv6 they can also solve it with PLATs running 464XLAT. The latter means they don't have to dual-stack their network, so it's cheaper and less error-prone. As long as they can get a CPE router which can do CLAT. Which is not much of a thing. Yet. The customers of the 464XLAT folks will occasionally want a public IPv4 address, so they'll solve that by tunnelling a static address for an extra charge. And like has happened with AWS, that'll become the standard: IPv6 and RFC1918 included, public IPv4 for an additional fee. As this happens, native IPv4 peering will become more challenging. With folks winnowing IPv4 from their network cores in favor of 464xlat there will be fewer places to trade IPv4 traffic. In addition, CGNAT and 464XLAT PLATs are challenging to manage. If your traffic is 90% IPv6, maybe the PLAT is a good candidate for outsourcing. So you buy PLAT service from an IPv4 exchange (IXPs: new product opportunity alert). And so on and so forth. 464xlat's CLATs never leave the CPE the same way modern POTS terminals still support rotary dialing but the IPv4 network collapses into a small core like Usenet has, serviced by long IPv6 tunnels. When I peer into my crystal ball in 2026, that's what I see. Regards, Bill Herrin -- For hire. https://bill.herrin.us/resume/ _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/QROS5Z47Y5LGTJCKF5YV5US6RHXENVKM/
