There really is no reason for 240/4 to remain "reserved". I share Dave's views, I would like to see 240/4 reclassified as unicast space and 2 x /8s delegated to each RIR with the /8s for AFRINIC to be held until their issues have been resolved.
Reclassifying this space, would add 10+ years onto the free pool for each RIR. Looking at the APNIC free pool, I would estimate there is about 1/6th of a /8 pool available for delegation, another 1/6th reserved. Reclassification would see available pool volumes return to pre-2010 levels. https://www.apnic.net/manage-ip/ipv4-exhaustion/ In the IETF draft that was co-authored by Dave as part of the IPv4 Unicast Extensions Project, a very strong case was presented to convert this space. https://www.ietf.org/archive/id/draft-schoen-intarea-unicast-240-00.html Regards, Christopher Hawker On Thu, 11 Jan 2024 at 20:40, Dave Taht <dave.t...@gmail.com> wrote: > On Wed, Jan 10, 2024 at 11:06 AM Tom Beecher <beec...@beecher.cc> wrote: > >> > >> There's a whole bunch of software out there that makes certain > >> assumptions about allowable ranges. That is, they've been compiled with > >> a header that defines .. > > > > > > Of course correct. It really depends on the vendor / software / versions > in an environment. A lot of vendors removed that years ago, because frankly > a lot of large networks have been using 240/4 as pseudo RFC1918 for years. > Others have worked with smaller vendors and open source projects to do the > same. > > > > It's consistently a topic in the debates about 240/4 reclassification. > > There's debates still? I gave up. After making 240/4 and 0/8 work > across all of linux and BSD and all the daemons besides bird (which > refused the patch , I took so much flack that I decided I would just > work on other things. So much of that flack was BS - like if you kill > the checks in the OS the world will end - that didn't happen. Linux > has had these two address ranges just work for over 5 years now. > > 240/4 is intensely routable and actually used in routers along hops > inside multiple networks today, but less so as a destination. > > I would really like, one day, to see it move from reserved to unicast > status, officially. I would have loved it if 0/8 was used by a space > RIR, behind CGNAT, for starters, but with a plan towards making it > routable. I am not holding my breath. > > The principal accomplishment of the whole unicast extensions project > was to save a nanosecond across all the servers in the world on every > packet by killing the useless 0/8 check. That patch paid for itself > the first weekend after that linux kernel deployed. It is the > simplest, most elegant, and most controversial patch I have ever > written. > > https://news.ycombinator.com/item?id=20430096 > > > > > > On Wed, Jan 10, 2024 at 10:45 AM Michael Butler < > i...@protected-networks.net> wrote: > >> > >> On 1/10/24 10:12, Tom Beecher wrote: > >> > Karim- > >> > > >> > Please be cautious about this advice, and understand the full context. > >> > > >> > 240/4 is still classified as RESERVED space. While you would certainly > >> > be able to use it on internal networks if your equipment supports it, > >> > you cannot use it as publicly routable space. There have been many > >> > proposals over the years to reclassify 240/4, but that has not > happened, > >> > and is unlikely to at any point in the foreseeable future. > >> > >> While you may be able to get packets from point A to B in a private > >> setting, using them might also be .. a challenge. > >> > >> There's a whole bunch of software out there that makes certain > >> assumptions about allowable ranges. That is, they've been compiled with > >> a header that defines .. > >> > >> #define IN_BADCLASS(i) (((in_addr_t)(i) & 0xf0000000) == 0xf0000000) > >> > >> Michael > >> > > > -- > 40 years of net history, a couple songs: > https://www.youtube.com/watch?v=D9RGX6QFm5E > Dave Täht CSO, LibreQos >
