Re: 202401100645.AYC Re: IPv4 address block

[Gaurav Kansal via NANOG <nanog () nanog org>]

+1 to the Christopher comment

> On 11-Jan-2024, at 16:24, 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