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> Who owns all these new addresses? You do. If you own an IPv4 address, you automatically own the entire 96‑bit subspace beneath it. Every IPv4 address becomes

> Who owns all these new addresses? You do. If you own an IPv4 address, you automatically own the entire 96‑bit subspace beneath it. Every IPv4 address becomes the root of a vast extended address tree. It has to work this way because any router that doesn’t understand IPv4x will still route purely on the old 32‑bit address. There’s no point assigning part of your subspace to someone else — their packets will still land on your router whether you like it or not. So the folks that just happen to get in early on the IPv4 address land rush (US, Western world) now also get to grab all this new address space? What about any new players? This particular aspect idea seems to reward incumbents. Unlike IPv6, where new players (and countries and continents) that weren't online early get a chance to get equal footing in the expanded address space.

wmf 7mo ago
The new players would each get a /24 and everyone would say that's "enough".
- avidiax 7mo ago
  Yeah, and the value of IPv4 address space would plummet, and there would be no reason for any company to own a /8. Clawing back address space would involve a few emails and a few months to get network configs ready.
- throw0101d 7mo ago
  > The new players would each get a /24 and everyone would say that's "enough". From where? All then-existing IPv4 addresses would get all the bits behind them. There would, at the time, still be IPv4 addresses available that could be given out, and as people got them they would also get the extend "IPv4x" address associated with them. But at some point IPv4 addresses would all be allocated… along with all the extended addresses 'behind' them. Then what? The extended IPv4x addresses are attached to the legacy IPv4 addressed they are 'prefixed' by, so once the legacy bits are assigned, so are the new bits. If someone comes along post-legacy-IPv4 exhaustion, where do new addresses come from? You're in the exact same situation as we are now: legacy code is stuck with 32-bit-only addresses, new code is >32-bits… just like with IPv6. Great you managed to purchase/rent a legacy address range… but you still need a translation box for non-updated code… like with CG-NAT and IPv6.
  - wmf 7mo ago
    ISPs can still get /24 of IPv4 today for free even after it "ran out". This comes from space that was set aside before runout. https://www.arin.net/participate/policy/nrpm/#4-10-dedicated-ipv4-allocation-to-facilitate-ipv6-deployment https://www.arin.net/participate/policy/nrpm/#4-10-dedicated... This IPv4x thing is bullshit but we should be accurate about how it would play out.
    - throw0101d 7mo ago
      So under this IPv4x proposal one gets an IPv4 /24, and receives a whole bunch of extended address space 'for free'. But right now you can get an IPv4 /24 (as you say), but you can get an IPv6 allocation 'for free' as we speak. In both cases legacy code cannot use the new address space; you have to: * update the IP stack (like with IPv6) * tell applications about new DNS records (like IPv6) * set up translation layers for legacy-only code to reach extended-only destination (like IPv6 with DNS64/NAT64, CLAT, etc) You're updating the exact same code paths in both the IPv4x and IPv6 scenarios: dual-stack, DNS, socket address structures, dealing with legacy-only code that is never touched to deal with the larger address space.
      - zadikian 7mo ago
        The point of IPv4x and similar proposals is to avoid a dual-stack scenario by reducing the risk of switching. Going from v4 to v4x doesn't mean changing all your routes and addresses (and possibly blacklists), you just enable it and everything still works. Network components can get updated/replaced with the longer addr field behind the scenes without user impact, then once the world is ready, ISPs can finally start using the extra address space.
        Dagger2 7mo ago
        But like the similar proposals, it fails to avoid a dual-stack scenario. Note that going from v4 to v6 also doesn't mean changing all your routes and addresses; you just enable it and everything still works. Network components can get updated behind the scenes without user impact. There's no flag day though; ISPs can start using the new address space as soon as they want, rather than being forced to wait until everybody else is ready.
- billpg 7mo ago
  Essentially.I imagined this hypothetical happening decades ago when there were still a few /8s unallocated. I suggested that those would be set aside for IPv4x only.
- zadikian 7mo ago
  This causes suboptimal routing, which is supposedly why they made v6 a clean slate instead. Still I think it would've been better than what we got with ipv6, plus maybe it'd be fixable over time.
IncreasePosts 7mo ago
If it became universally adopted, then there wouldn't be much need for owning crazy amounts of ipv4 addresses, so the price of addresses would drop. If this proposal was not adopted universally, then we would be pretty much in the same situation as we are with ipv4 addresses

wmf 7mo ago

The new players would each get a /24 and everyone would say that's "enough".

avidiax 7mo ago
Yeah, and the value of IPv4 address space would plummet, and there would be no reason for any company to own a /8. Clawing back address space would involve a few emails and a few months to get network configs ready.
throw0101d 7mo ago
> The new players would each get a /24 and everyone would say that's "enough". From where? All then-existing IPv4 addresses would get all the bits behind them. There would, at the time, still be IPv4 addresses available that could be given out, and as people got them they would also get the extend "IPv4x" address associated with them. But at some point IPv4 addresses would all be allocated… along with all the extended addresses 'behind' them. Then what? The extended IPv4x addresses are attached to the legacy IPv4 addressed they are 'prefixed' by, so once the legacy bits are assigned, so are the new bits. If someone comes along post-legacy-IPv4 exhaustion, where do new addresses come from? You're in the exact same situation as we are now: legacy code is stuck with 32-bit-only addresses, new code is >32-bits… just like with IPv6. Great you managed to purchase/rent a legacy address range… but you still need a translation box for non-updated code… like with CG-NAT and IPv6.
- wmf 7mo ago
  ISPs can still get /24 of IPv4 today for free even after it "ran out". This comes from space that was set aside before runout. https://www.arin.net/participate/policy/nrpm/#4-10-dedicated-ipv4-allocation-to-facilitate-ipv6-deployment https://www.arin.net/participate/policy/nrpm/#4-10-dedicated... This IPv4x thing is bullshit but we should be accurate about how it would play out.
  - throw0101d 7mo ago
    So under this IPv4x proposal one gets an IPv4 /24, and receives a whole bunch of extended address space 'for free'. But right now you can get an IPv4 /24 (as you say), but you can get an IPv6 allocation 'for free' as we speak. In both cases legacy code cannot use the new address space; you have to: * update the IP stack (like with IPv6) * tell applications about new DNS records (like IPv6) * set up translation layers for legacy-only code to reach extended-only destination (like IPv6 with DNS64/NAT64, CLAT, etc) You're updating the exact same code paths in both the IPv4x and IPv6 scenarios: dual-stack, DNS, socket address structures, dealing with legacy-only code that is never touched to deal with the larger address space.
    - zadikian 7mo ago
      The point of IPv4x and similar proposals is to avoid a dual-stack scenario by reducing the risk of switching. Going from v4 to v4x doesn't mean changing all your routes and addresses (and possibly blacklists), you just enable it and everything still works. Network components can get updated/replaced with the longer addr field behind the scenes without user impact, then once the world is ready, ISPs can finally start using the extra address space.
      - Dagger2 7mo ago
        But like the similar proposals, it fails to avoid a dual-stack scenario. Note that going from v4 to v6 also doesn't mean changing all your routes and addresses; you just enable it and everything still works. Network components can get updated behind the scenes without user impact. There's no flag day though; ISPs can start using the new address space as soon as they want, rather than being forced to wait until everybody else is ready.
billpg 7mo ago
Essentially.I imagined this hypothetical happening decades ago when there were still a few /8s unallocated. I suggested that those would be set aside for IPv4x only.
zadikian 7mo ago
This causes suboptimal routing, which is supposedly why they made v6 a clean slate instead. Still I think it would've been better than what we got with ipv6, plus maybe it'd be fixable over time.

IncreasePosts 7mo ago

If it became universally adopted, then there wouldn't be much need for owning crazy amounts of ipv4 addresses, so the price of addresses would drop. If this proposal was not adopted universally, then we would be pretty much in the same situation as we are with ipv4 addresses