Good morning kernel hackers,
we are a small company in Switzerland running some IPv6 only networks. The systems in the IPv6 only networks do not need any IPv4 support anymore and thus for switches/routers we turned the support off. Today we tried to turn off IPv4 in the Linux kernel at compile time. But it seems that as soon as we turn off CONFIG_INET, CONFIG_IPV6 is automatically turned off as well. While you can argue that "turning off IPv4 is not necessary", this is not our point. As IPv4 resources have depleted almost everywhere in the world a move to IPv6 is inevitable, especially if you are a small organisation offering Internet services. Being a (new) small organisation you are already disadvantaged in terms of IPv4 resources that you can afford, so our objective is to make the life in the IPv6 world as easy as possible. If we can build operating systems that don't run IPv4 anymore, operators have at least a certain degree of complexity less and can start fresh into adventures, without having to care about iptables, about IPv4 routing, etc. Coming back to my original question: is there a way or how would we turn off IPv4 support in the Linux kernel? So far the only operating system that is reported to be able to run without IPv4 is FreeBSD [0], but I hope we can add more in the near future. Best, Nico [0] https://ungleich.ch/en-us/cms/blog/2019/01/09/die-ipv4-die/ -- Your Swiss, Open Source and IPv6 Virtual Machine. Now on www.datacenterlight.ch.
