240/4 (Re: 44/8)

Tue Jul 23 03:48:23 UTC 2019

> On Jul 22, 2019, at 20:14 , Mikael Abrahamsson <swmike at swm.pp.se> wrote:
> 
> On Mon, 22 Jul 2019, Owen DeLong wrote:
> 
>> 	2.	It was decided that the effort to modify each and every IP stack in order to facilitate use of this relatively small block (16 /8s being evaluated against a global
>> 		run rate at the time of roughly 2.5 /8s per month, mostly to RIPE and APNIC) vs. putting that same effort into modifying each and every IP stack to support
>> 		IPv6 was an equation of very small benefit for slightly smaller cost. (Less than 8 additional months of IPv4 free pool vs. hopefully making IPv6 deployable
>> 		before IPv4 ran out).
> 
> Well, people are working on making 240/4 usable in IP stacks:
> 
> https://raw.githubusercontent.com/dtaht/unicast-extensions/master/rfcs/draft-gilmore-taht-v4uniext.txt
> 
> There have been patches accepted into some BSDs and into Linux tools/kernel and other operating systems to make 240/4 configurable and working as unicast space.
> 
> I don't expect it to show up in DFZ anytime soon, but some people have dilligently been working on removing any obstacles to using 240/4 in most common operating systems.
> 
> For controlled environments, it's probably deployable today with some caveats. I think it'd be fine as a compliment to RFC1918 space for some internal networks.
> 
> -- 
> Mikael Abrahamsson    email: swmike at swm.pp.se

I guess people can do whatever they want. I personally consider it to be a sad sad waste of time that could be better spent deploying IPv6 to more places.

Owen