Re: 202401100645.AYC Re: IPv4 address block

[Owen DeLong via NANOG <nanog () nanog org>]

At the time this was being considered, ARIN, APNIC, and RIPE NCC were each burning approximately 6 /8s per year. 240/4 
is 16x/8, so with an RIR burn rate of 18 /8s per year (not counting LACNIC and AFRINIC which each accounted for <1 per 
year IIRC), it seemed the 240/4 lasting a year was an optimistic count.

Owen


> On Jan 11, 2024, at 13:15, Christopher Hawker <chris () thesysadmin au> wrote:
>
> Hi Tom,
>
> I'm not too sure I understand where the idea came from that 2 x /8 would only last one year. APNIC received their 
> final allocation of the 103/8 prefix from ICANN/IANA on 03 February 2011, and commenced delegating space from the 
> prefix on 18 April 2011. With the right policies in place, it can be well and truly extended.
>
> Looking at an APNIC Blog article authored by Guangliang Pan on 09 October 2023 
> (https://blog.apnic.net/2023/10/09/nearing-the-end-of-103-8/), as of the time the article was written there were 121 
> available /24 prefixes from the 103/8 pool still available. Not a great deal in the grand scheme of things, however, 
> it demonstrates that policy works in preserving what finite resources we have left, and that a 2 x /8 will last a lot 
> longer than one year.
>
> I could say the same, that 2 x /8 lasting a little more than a year is an extremely remote and highly unlikely 
> assumption. Bear in mind that APNIC policy was changed 1/2 way through to drop 103/8 delegations from a /22 to a /23. 
> Based on this, 65,536 x /23 delegations can be made to new members and as Peter said, if post-exhaustion policy is 
> applied to 240/4 it'll go an extremely long way.
>
> Regards,
> Christopher Hawker
>
>
>
> On Fri, 12 Jan 2024 at 04:26, Tom Beecher <beecher () beecher cc <mailto:beecher () beecher cc>> wrote:
> > Christopher-
> >
> > > 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.
> >
> > Citing Nick Hilliard from another reply, this is an incorrect statement. 
> >
> > > on this point: prior to RIR depletion, the annual global run-rate on /8s
> > > measured by IANA was ~13 per annum. So that suggests that 240/4 would
> > > provide a little more than 1Y of consumption, assuming no demand
> > > back-pressure, which seems an unlikely assumption.
> >
> > > 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.
> >
> > This has been discussed at great length at IETF. The consensus on the question has been consistent for many years 
> > now; doing work to free up 12-ish months of space doesn't make much sense when IPv6 exists, along with plenty of 
> > transition/translation mechanisms. Unless someone is able to present new arguments that change the current 
> > consensus, it's not going to happen. 
> >
> > On Thu, Jan 11, 2024 at 5:54 AM Christopher Hawker <chris () thesysadmin au <mailto:chris () thesysadmin au>> wrote:
> > > 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.taht () gmail com <mailto:dave.taht () gmail com>> wrote:
> > > > On Wed, Jan 10, 2024 at 11:06 AM Tom Beecher <beecher () beecher cc <mailto:beecher () 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 <imb () protected-networks net <mailto:imb () 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