5 ms·

> A much better solution here would have been an incredibly conservative change to ipv4 to expand the number of available address space "And what do you base t

by hypeatei 10mo ago

> A much better solution here would have been an incredibly conservative change to ipv4 to expand the number of available address space "And what do you base this belief on? Fact is you'd run into exactly the same problems as with IPv6. Sure, network-enabled software might be easier to rewrite to support 40-bit IPv4+, but any hardware-accelerated products (routers, switches, network cards, etc.) would still need replacement (just as with IPv6), and you'd still need everyone to be assigned unique IPv4+ addresses in order to communicate with each other (just as with IPv6)."[0] 0: https://news.ycombinator.com/item?id=37120422 https://news.ycombinator.com/item?id=37120422

redox99 10mo ago
Hardware would catch up. And IPv4 would never go away. If you connect to 1.1.1.1 it would still be good ole IPv4. You would only have in addition the option to connect to 1.1.1.1.1.1.1.2 if the entire chain supports it. And if not, it could still be worked around through software with proxies and NAT.
- hypeatei 10mo ago
  So... just a less ambitious IPv6 that would still require dual-stack networking setups? The current adoption woes would've happened regardless, unless someone comes up with a genius idea that doesn't require any configuration/code changes.
  - krupan 10mo ago
    I disagree. The current adoption woes are exactly because IPv6 is so different from IPv4. Everyone who tries it out learns the hard way that most of what they know from IPv4 doesn't apply. A less ambitious IPv4 is exactly what we need in order to make any progress
    - sgjohnson 10mo ago
      But that is a bug in history. IPv6 was standardized BEFORE NAT. “most what they know from IPv6” is just NAT. > A less ambitious IPv4 is exactly what we need in order to make any progress but we’re already making very good progress with IPv6? Global traffic to Google is >50% IPv6 already.
      - btilly 10mo ago
        Current statistics are that a bit over 70% of websites are IPv4 only. A bit under 30% allow IPv6. IPv6 only websites are a rounding error. Therefore if I'm on an IPv6 phone, odds are very good that my traffic winds up going over IPv4 internet at some point. We're 30 years into the transition. We are still decades away from it being viable for servers to run IPv6 first. You pretty much have to do IPv4 on a server. IPv6 is an afterthought.
        sgjohnson 10mo ago
        > We are still decades away from it being viable for servers to run IPv6 first. Just put Cloudflare in front of it. You don’t need to use IPv4 on servers AT ALL. Only on the edge. You can easily run IPv6-only internally. It’s definitely not an afterthought for any new deployments. In fact there’s even a US gov’t mandate to go IPv6-first. It’s the eyeballs that need IPv4. It’s a complete non-issue for servers.
        btilly 10mo ago
        You have a point. But you still need DNS to an IPv4 address. And the fact that about 70% of websites are IPv4 only means that if you're setting up a new website, odds are good that you won't do IPv6 in the first pass.
        sgjohnson 10mo ago
        Cloudflare proxy automatically creates A and AAAA records. And you can’t even disable AAAA ones, except in the Enterprise plan. So if you use Cloudflare, your website simply is going to be accessible over both protocols, irrespective of the one you actually choose. Unless you’re on Enterprise and go out of your way to disable it.
    - bc569a80a344f9c 10mo ago
      It’s not _that_ different. Larger address space, more emphasis on multicast for some basic functions. If you understand those functions in IPv4, learning IPv6 is very straightforward. There’s some footguns once you get to enterprise scale deployments but that’s just as true of IPv4.
      - krupan 10mo ago
        Lol! IPv4 uses zero multicast (I know, I know, technically there's multicast, but we all just understand broadcast). The parts of an IPv4 address and their meaning have almost no correlation to the parts of an IPv6 address and their meaning. Those are pretty fundamental differences.
        bc569a80a344f9c 10mo ago
        IP addresses in both protocols are just a sequence of bits. Combined with a subnet mask (or prefix length, the more modern term for the same concept) they divide into a network portion and a host portion. The former tells you what network the host is on, the latter uniquely identifies the host on that network. This is exactly the same for both protocols. Or what do you mean by “parts of an IPv4 address and their meaning”? That multicast on IPv4 isn’t used as much is irrelevant. It functions the same way in both protocols.
        elcritch 10mo ago
        IPv4 uses ARP which is just a half baked multicast. IPv6 is much better designed.
      - almosthere 10mo ago
        multicast has been dead for years
      - morshu9001 10mo ago
        The biggest difference is often overlooked because it's not part of the packet format or anything: IPv4 /32s were not carried over to IPv6. If you owned 1.1.1.1 on ipv4, and you switch to ipv6, you get an entirely different address instead of 1.1.1.1::. Maaybe you get an ipv6-mapped-ipv4 ::ffff:1.1.1.1, but that's temporary and isn't divisible into like 1.1.1.1.2. And then all the defaults about how basically everything works are different. Home router in v6 mode means no DHCP, no NAT, and hopefully yes firewall. In theory you can make it work a lot like v4, but by default it's not.
    - throw0101a 10mo ago
      > I disagree. The current adoption woes are exactly because IPv6 is so different from IPv4. How is IPv6 "so different" than IPv4 when looking at Layer 3 and above? (Certainly ARP vs ND is different.)
      - krupan 10mo ago
        I didn't say it was different 'when looking at layer 3 and above". I said it's different from IPv4. At the IP layer.
        Dylan16807 10mo ago
        At the IP layer just being different is 90% of the trouble. Being less ambitious would have some upsides and downsides but not seriously change that.
        throw0101a 10mo ago
        > I said it's different from IPv4. At the IP layer. In what way? Longer addresses? In what way is it "so different" that people are unable to handle whatever differences you are referring to? We used to have IPv4, NetBEUI, AppleTalk, IPX all in regular use in the past: and that's just on Ethernet (of various flavours), never mind different Layer 2s. Have network folks become so dim over the last few years that they can't handle a different protocol now?
    - morshu9001 10mo ago
      Part of the ipv6 ambition was fixing all the suboptimally allocated ipv4 routes. They considered your idea and decided against it for that reason. But had they done it, we would've already been on v6 for years and had plenty of time to build some cleaner routes too. I think they also wanted to kill NAT and DHCP everywhere, so there's SLAAC by default. But turns out NAT is rather user-friendly in many cases! They even had to bolt on that v6 privacy extension.
      - cylemons 10mo ago
        What do you mean by suboptimal allocation?
        _ikke_ 10mo ago
        The ipv4 routing table contains many individual /24 subnets that cannot be summarized, causing bloat in the routing tables. With ipv6, that can be simplified with just a couple of /32 or /48 prefixes per AS.
        morshu9001 10mo ago
        This, because a bunch of random /24s were sold off to different ISPs, because of address scarcity.
    - lmm 10mo ago
      > The current adoption woes are exactly because IPv6 is so different from IPv4. Everyone who tries it out learns the hard way that most of what they know from IPv4 doesn't apply. In my experience the differences are just an excuse, and however similar you made the protocol to IPv4 the people who wanted an excuse would still manage to find one. Deploying IPv6 is really not hard, you just have to actually try.
  - hackthemack 10mo ago
    Sort of. I think people would understand 201.20.188.24.6 And most of what they know about how it works clicks in their mind. It just has an extra octet. I also think hardware would have been upgraded faster.
    - sedawkgrep 10mo ago
      It would've been even easier and lasted longer to use two bytes of hex at the start. That would've expanded the Internet to 65536x its current space. Something like aaff:a.b.c.d Leaving off the prefix: could just mean strictly IPv4.
      - cylemons 10mo ago
        I think making the extra hex at the end is better, that way its like we are subdividing our existing networks without moving them around
      - Macha 10mo ago
        In IPv6, this is spelled ::ff00:a.b.c.d It didn’t speed up adoption and people then tried most of the other solutions people are going to suggest for IPv4+. Want the IPv4 address as the network address instead? That’s 2002:a.b.c.d/48 - many ISPs didn’t deploy that either
    - deleted 10mo ago
      [deleted]
    - raffraffraff 10mo ago
      Think of it like phone numbers. For decades people have accepted gradual phone number prefix additions. I remember in rural Ireland my parents got an extra digit in the late 70s, two more in the 90s, and it was conceptually easy. It didn't change how phones work, turn your phone into a party line or introduce letters or special characters into the rotary dial, or allow you to skip consecutive similar digits. For people who deal with ip addresses, the switch from ipv4 to ipv6 means moving from 4 digits (1.2.3.4) to this: 2001:0db8:0000:0000:0008:0800:200c:417a 2001:db8:0:0:8:800:200c:417a 2001:db8::8:800:200c:417a Yes, the ipv6 examples are all the same address. This is horrible. Worse than MAC addresses because it doesn't even follow a standard length and has fancy (read: complex) rules for shortening. Plus switching completely to ipv6 overnight means throwing away all your current knowledge of how to secure your home network. For lazy people, ipv4 NAT "accidentally" provides firewall-like features because none of your home ipv4 addresses are public. People are immediately afraid of ipv6 in the home and now they need to know about firewalls. With ipv4, firewalls were simple enough. "My network starts with 192.168, the Internet doesn't". You need to learn unlearn NAT and port forwarding and realise that with already routable ipv6 addresses you just need a firewall with default deny, and then add rules that "unlock" traffic on specific ports to specific addresses. Of course more complexity gets in the way... devices use "Privacy Extensions" and change their addresses, so making firewall rules work long-term, you should use the device's MAC Address. Christ on a bike. I totally see why people open this bag of crazy shit and say to themselves "maybe next time I buy a new router I'll do this, but right now I have a home with 4 phones, 3 TVs, 2 consoles, security cameras, and some god damn kitchen appliances that want to talk to home connect or something". Personally, I try to avoid fucking with the network as much as possible to avoid the wrath of my wife (her voice "Why are you breaking shit for ideological reasons? What was broken? What new amazing thing can I do after this?").
  - redox99 10mo ago
    The main thing is keeping current addresses, not having both an ipv4 and ipv6 address. Just like for an apartment you append something like 5B. And for a house you don't need that.
- deleted 10mo ago
  [deleted]
avidiax 10mo ago
> Fact is you'd run into exactly the same problems as with IPv6. If you treat IPv4 addresses as a routable prefix (same as today), then the internet core routers don't change at all. Only the edge equipment would need to be IPv4+ aware. And even that awareness could be quite gradual, since you would have NAT to fall back on when receiving an IPv4 classic packet at the network. It can even be customer deployed. Add an IPv4+ box on the network, assign it the DMZ address, and have it hand out public IPV4+ addresses and NAT them to the local IPv4 private subnet. IPv6 seems to be a standard that suffered from re-design by committee. Lots of good ideas were incorporated, but it resulted in a stack that had only complicated backwards compatibility. It has taken the scale of mobile carriers to finally make IPv6 more appealing in some cases than IPv4+NAT, but I think we are still a long way from any ISP being able to disable IPv4 support.
- sgjohnson 10mo ago
  > Only the edge equipment would need to be IPv4+ aware. And even that awareness could be quite gradual, since you would have NAT to fall back on when receiving an IPv4 classic packet at the network. It can even be customer deployed. Add an IPv4+ box on the network, assign it the DMZ address, and have it hand out public IPV4+ addresses and NAT them to the local IPv4 private subnet. Congratulations, you’ve re-invented CGNAT, with none of the benefits, and the additional hassle of it being an entirely new protocol! No. No “extra bits” on an IPv4 address would have ever worked. NAT itself is a bug. Suggesting that as an intentional design is disingenuous.
  - avidiax 10mo ago
    I have not "reinvented CGNAT". It is hierarchal public addressing similar to IPv4 and IPv6. The edge router has an IPv4+ subnet (either a classic v4 address, or part of a v4+ address). It maintains an L2 routing table with ARP+, and routes IPv4+ packets to the endpoint without translation. Private subnetting and NAT is only needed to support legacy IPv4 clients. CGNAT pools IPv4 public addresses and has an expanded key for each connection, and translates either 4 to 6 or into a private IPv4 subnet. My proposal needs no pooling and only requires translation if the remote host is IPv4 classic and the edge router is not assigned a full IPv4+/24.
btilly 10mo ago
I agree with that belief, and I've been saying it for over 20 years. I base it on comparing how the IPv2 to IPv4 rollout went, versus the IPv4 to IPv6 rollout. The fact that it was incredibly obvious how to route IPv2 over IPv4 made it a no-brainer for the core Internet to be upgraded to IPv4. By contrast it took over a decade for IPv6 folks to accept that IPv6 was never going to rule the world unless you can route IPv4 over it. Then we got DS-Lite. Which, because IPv6 wasn't designed to do that, adds a tremendous amount of complexity. Will we eventually get to an IPv6 only future? We have to. There is no alternative. But the route is going to be far more painful than it would have been if backwards compatibility was part of the original design. Of course the flip side is that some day we don't need IPv4 backwards compatibility. But that's still decades from now. How many on the original IPv6 will even still be alive to see it?
- Macha 10mo ago
  The IPv2 to IPv4 migration involved sysadmins at less than 50 institutions (primarily universities and research labs), updating things they considered to be a research project, that didn’t have specialised network hardware that knew anything about IP, and any networked software was primarily written either by the sysadmins themselves or people that one of them could walk down the corridor to the office of. Oh, and several months of downtime if someone was too busy to update right now was culturally acceptable. It’s not remotely the same environment as existed at the time of IPv6 being designed
almosthere 10mo ago
The IPv4+ could pass through a router that doesn't know about it - the cloud host that receives that packet could interpret it in a special way, in fact you could stuff additional data into the next layer of the stack for routing - it's not like many services beyond TCP would need to support the scheme.
- viraptor 10mo ago
  > The IPv4+ could pass through a router that doesn't know about it It couldn't do that reliably. We don't have any flags left for that that. Options are not safe. We've got one reserved flag which is anyways set to 0, so that's not safe either.
  - magicalhippo 10mo ago
    > We don't have any flags left for that that. There's the reserved bit (aka the evil bit[1]). Are you saying gear out there drops packets with reserved bit set to 1? Wouldn't surprise me, just curious. Seems like IPv4+ would have been a good time to use that bit. Any IPv4+ packets could have more flags in the + portion of the header, if needed. [1]: https://en.wikipedia.org/wiki/Evil_bit https://en.wikipedia.org/wiki/Evil_bit
    - viraptor 10mo ago
      That bit is currently defined as "Bit 0: reserved, must be zero", so there will be network gear out there, that either drops the packet otherwise or resets the bit to 0 when forwarding.
      - magicalhippo 10mo ago
        That makes it effectively impossible to ever use then, so a waste of a bit. Too bad they made that mistake when writing the spec. Would have been better if they specified it like most APIs, ie ignore if you get it, carry it if you forward, and set it to zero if you send it.
morshu9001 10mo ago
Hardware support for ipv6 hasn't been the limiting factor in a long time. Users higher on the stack don't want to adopt something that makes so many unnecessary changes.
solarkraft 10mo ago
You’re focusing on the technical difficulty of implementing it in software. This is not the problem. IPv6 support is now present in almost every product, but people still refuse to set it up because it’s so different to what they’re used to (I’m not arguing whether the changes are good - they’re just changes). IPv4+ would’ve solved this social problem.
- doctorpangloss 10mo ago
  There’s absolutely, utterly zero chance IPv4+ would be adopted. CGNAT is the solution to the social problem. I don’t even buy your way of thinking - unlike an “engineering” solution or an “incentives” solution, the problem with “social solutions I speculate about” is: they offer nothing until implemented. They are literally all the same, no difference between the whole world of social solutions, until they are adopted. They are meaningless. They’re the opposite of plans. Like what’s the difference between IPv4+, which doesn’t exist, and “lets pass a law that mandates ipv6 support”? Nothing. This is what the mockery of “just pass a law” is about. I don’t like those guys, but they are right: it’s meaningless.
  - solarkraft 10mo ago
    This is a good point. The same “why should I migrate” would affect it. However, it being so close to the predecessor, it would be much easier to do so, catching way more people who are on the fence.

redox99 10mo ago

Hardware would catch up. And IPv4 would never go away. If you connect to 1.1.1.1 it would still be good ole IPv4. You would only have in addition the option to connect to 1.1.1.1.1.1.1.2 if the entire chain supports it. And if not, it could still be worked around through software with proxies and NAT.

hypeatei 10mo ago
So... just a less ambitious IPv6 that would still require dual-stack networking setups? The current adoption woes would've happened regardless, unless someone comes up with a genius idea that doesn't require any configuration/code changes.
- krupan 10mo ago
  I disagree. The current adoption woes are exactly because IPv6 is so different from IPv4. Everyone who tries it out learns the hard way that most of what they know from IPv4 doesn't apply. A less ambitious IPv4 is exactly what we need in order to make any progress
  - sgjohnson 10mo ago
    But that is a bug in history. IPv6 was standardized BEFORE NAT. “most what they know from IPv6” is just NAT. > A less ambitious IPv4 is exactly what we need in order to make any progress but we’re already making very good progress with IPv6? Global traffic to Google is >50% IPv6 already.
    - btilly 10mo ago
      Current statistics are that a bit over 70% of websites are IPv4 only. A bit under 30% allow IPv6. IPv6 only websites are a rounding error. Therefore if I'm on an IPv6 phone, odds are very good that my traffic winds up going over IPv4 internet at some point. We're 30 years into the transition. We are still decades away from it being viable for servers to run IPv6 first. You pretty much have to do IPv4 on a server. IPv6 is an afterthought.
      - sgjohnson 10mo ago
        > We are still decades away from it being viable for servers to run IPv6 first. Just put Cloudflare in front of it. You don’t need to use IPv4 on servers AT ALL. Only on the edge. You can easily run IPv6-only internally. It’s definitely not an afterthought for any new deployments. In fact there’s even a US gov’t mandate to go IPv6-first. It’s the eyeballs that need IPv4. It’s a complete non-issue for servers.
        btilly 10mo ago
        You have a point. But you still need DNS to an IPv4 address. And the fact that about 70% of websites are IPv4 only means that if you're setting up a new website, odds are good that you won't do IPv6 in the first pass.
        sgjohnson 10mo ago
        Cloudflare proxy automatically creates A and AAAA records. And you can’t even disable AAAA ones, except in the Enterprise plan. So if you use Cloudflare, your website simply is going to be accessible over both protocols, irrespective of the one you actually choose. Unless you’re on Enterprise and go out of your way to disable it.
  - bc569a80a344f9c 10mo ago
    It’s not _that_ different. Larger address space, more emphasis on multicast for some basic functions. If you understand those functions in IPv4, learning IPv6 is very straightforward. There’s some footguns once you get to enterprise scale deployments but that’s just as true of IPv4.
    - krupan 10mo ago
      Lol! IPv4 uses zero multicast (I know, I know, technically there's multicast, but we all just understand broadcast). The parts of an IPv4 address and their meaning have almost no correlation to the parts of an IPv6 address and their meaning. Those are pretty fundamental differences.
      - bc569a80a344f9c 10mo ago
        IP addresses in both protocols are just a sequence of bits. Combined with a subnet mask (or prefix length, the more modern term for the same concept) they divide into a network portion and a host portion. The former tells you what network the host is on, the latter uniquely identifies the host on that network. This is exactly the same for both protocols. Or what do you mean by “parts of an IPv4 address and their meaning”? That multicast on IPv4 isn’t used as much is irrelevant. It functions the same way in both protocols.
      - elcritch 10mo ago
        IPv4 uses ARP which is just a half baked multicast. IPv6 is much better designed.
    - almosthere 10mo ago
      multicast has been dead for years
    - morshu9001 10mo ago
      The biggest difference is often overlooked because it's not part of the packet format or anything: IPv4 /32s were not carried over to IPv6. If you owned 1.1.1.1 on ipv4, and you switch to ipv6, you get an entirely different address instead of 1.1.1.1::. Maaybe you get an ipv6-mapped-ipv4 ::ffff:1.1.1.1, but that's temporary and isn't divisible into like 1.1.1.1.2. And then all the defaults about how basically everything works are different. Home router in v6 mode means no DHCP, no NAT, and hopefully yes firewall. In theory you can make it work a lot like v4, but by default it's not.
  - throw0101a 10mo ago
    > I disagree. The current adoption woes are exactly because IPv6 is so different from IPv4. How is IPv6 "so different" than IPv4 when looking at Layer 3 and above? (Certainly ARP vs ND is different.)
    - krupan 10mo ago
      I didn't say it was different 'when looking at layer 3 and above". I said it's different from IPv4. At the IP layer.
      - Dylan16807 10mo ago
        At the IP layer just being different is 90% of the trouble. Being less ambitious would have some upsides and downsides but not seriously change that.
      - throw0101a 10mo ago
        > I said it's different from IPv4. At the IP layer. In what way? Longer addresses? In what way is it "so different" that people are unable to handle whatever differences you are referring to? We used to have IPv4, NetBEUI, AppleTalk, IPX all in regular use in the past: and that's just on Ethernet (of various flavours), never mind different Layer 2s. Have network folks become so dim over the last few years that they can't handle a different protocol now?
  - morshu9001 10mo ago
    Part of the ipv6 ambition was fixing all the suboptimally allocated ipv4 routes. They considered your idea and decided against it for that reason. But had they done it, we would've already been on v6 for years and had plenty of time to build some cleaner routes too. I think they also wanted to kill NAT and DHCP everywhere, so there's SLAAC by default. But turns out NAT is rather user-friendly in many cases! They even had to bolt on that v6 privacy extension.
    - cylemons 10mo ago
      What do you mean by suboptimal allocation?
      - _ikke_ 10mo ago
        The ipv4 routing table contains many individual /24 subnets that cannot be summarized, causing bloat in the routing tables. With ipv6, that can be simplified with just a couple of /32 or /48 prefixes per AS.
        morshu9001 10mo ago
        This, because a bunch of random /24s were sold off to different ISPs, because of address scarcity.
  - lmm 10mo ago
    > The current adoption woes are exactly because IPv6 is so different from IPv4. Everyone who tries it out learns the hard way that most of what they know from IPv4 doesn't apply. In my experience the differences are just an excuse, and however similar you made the protocol to IPv4 the people who wanted an excuse would still manage to find one. Deploying IPv6 is really not hard, you just have to actually try.
- hackthemack 10mo ago
  Sort of. I think people would understand 201.20.188.24.6 And most of what they know about how it works clicks in their mind. It just has an extra octet. I also think hardware would have been upgraded faster.
  - sedawkgrep 10mo ago
    It would've been even easier and lasted longer to use two bytes of hex at the start. That would've expanded the Internet to 65536x its current space. Something like aaff:a.b.c.d Leaving off the prefix: could just mean strictly IPv4.
    - cylemons 10mo ago
      I think making the extra hex at the end is better, that way its like we are subdividing our existing networks without moving them around
    - Macha 10mo ago
      In IPv6, this is spelled ::ff00:a.b.c.d It didn’t speed up adoption and people then tried most of the other solutions people are going to suggest for IPv4+. Want the IPv4 address as the network address instead? That’s 2002:a.b.c.d/48 - many ISPs didn’t deploy that either
  - deleted 10mo ago
    [deleted]
  - raffraffraff 10mo ago
    Think of it like phone numbers. For decades people have accepted gradual phone number prefix additions. I remember in rural Ireland my parents got an extra digit in the late 70s, two more in the 90s, and it was conceptually easy. It didn't change how phones work, turn your phone into a party line or introduce letters or special characters into the rotary dial, or allow you to skip consecutive similar digits. For people who deal with ip addresses, the switch from ipv4 to ipv6 means moving from 4 digits (1.2.3.4) to this: 2001:0db8:0000:0000:0008:0800:200c:417a 2001:db8:0:0:8:800:200c:417a 2001:db8::8:800:200c:417a Yes, the ipv6 examples are all the same address. This is horrible. Worse than MAC addresses because it doesn't even follow a standard length and has fancy (read: complex) rules for shortening. Plus switching completely to ipv6 overnight means throwing away all your current knowledge of how to secure your home network. For lazy people, ipv4 NAT "accidentally" provides firewall-like features because none of your home ipv4 addresses are public. People are immediately afraid of ipv6 in the home and now they need to know about firewalls. With ipv4, firewalls were simple enough. "My network starts with 192.168, the Internet doesn't". You need to learn unlearn NAT and port forwarding and realise that with already routable ipv6 addresses you just need a firewall with default deny, and then add rules that "unlock" traffic on specific ports to specific addresses. Of course more complexity gets in the way... devices use "Privacy Extensions" and change their addresses, so making firewall rules work long-term, you should use the device's MAC Address. Christ on a bike. I totally see why people open this bag of crazy shit and say to themselves "maybe next time I buy a new router I'll do this, but right now I have a home with 4 phones, 3 TVs, 2 consoles, security cameras, and some god damn kitchen appliances that want to talk to home connect or something". Personally, I try to avoid fucking with the network as much as possible to avoid the wrath of my wife (her voice "Why are you breaking shit for ideological reasons? What was broken? What new amazing thing can I do after this?").
- redox99 10mo ago
  The main thing is keeping current addresses, not having both an ipv4 and ipv6 address. Just like for an apartment you append something like 5B. And for a house you don't need that.
deleted 10mo ago
[deleted]

avidiax 10mo ago

> Fact is you'd run into exactly the same problems as with IPv6. If you treat IPv4 addresses as a routable prefix (same as today), then the internet core routers don't change at all. Only the edge equipment would need to be IPv4+ aware. And even that awareness could be quite gradual, since you would have NAT to fall back on when receiving an IPv4 classic packet at the network. It can even be customer deployed. Add an IPv4+ box on the network, assign it the DMZ address, and have it hand out public IPV4+ addresses and NAT them to the local IPv4 private subnet. IPv6 seems to be a standard that suffered from re-design by committee. Lots of good ideas were incorporated, but it resulted in a stack that had only complicated backwards compatibility. It has taken the scale of mobile carriers to finally make IPv6 more appealing in some cases than IPv4+NAT, but I think we are still a long way from any ISP being able to disable IPv4 support.

sgjohnson 10mo ago
> Only the edge equipment would need to be IPv4+ aware. And even that awareness could be quite gradual, since you would have NAT to fall back on when receiving an IPv4 classic packet at the network. It can even be customer deployed. Add an IPv4+ box on the network, assign it the DMZ address, and have it hand out public IPV4+ addresses and NAT them to the local IPv4 private subnet. Congratulations, you’ve re-invented CGNAT, with none of the benefits, and the additional hassle of it being an entirely new protocol! No. No “extra bits” on an IPv4 address would have ever worked. NAT itself is a bug. Suggesting that as an intentional design is disingenuous.
- avidiax 10mo ago
  I have not "reinvented CGNAT". It is hierarchal public addressing similar to IPv4 and IPv6. The edge router has an IPv4+ subnet (either a classic v4 address, or part of a v4+ address). It maintains an L2 routing table with ARP+, and routes IPv4+ packets to the endpoint without translation. Private subnetting and NAT is only needed to support legacy IPv4 clients. CGNAT pools IPv4 public addresses and has an expanded key for each connection, and translates either 4 to 6 or into a private IPv4 subnet. My proposal needs no pooling and only requires translation if the remote host is IPv4 classic and the edge router is not assigned a full IPv4+/24.

btilly 10mo ago

I agree with that belief, and I've been saying it for over 20 years. I base it on comparing how the IPv2 to IPv4 rollout went, versus the IPv4 to IPv6 rollout. The fact that it was incredibly obvious how to route IPv2 over IPv4 made it a no-brainer for the core Internet to be upgraded to IPv4. By contrast it took over a decade for IPv6 folks to accept that IPv6 was never going to rule the world unless you can route IPv4 over it. Then we got DS-Lite. Which, because IPv6 wasn't designed to do that, adds a tremendous amount of complexity. Will we eventually get to an IPv6 only future? We have to. There is no alternative. But the route is going to be far more painful than it would have been if backwards compatibility was part of the original design. Of course the flip side is that some day we don't need IPv4 backwards compatibility. But that's still decades from now. How many on the original IPv6 will even still be alive to see it?

Macha 10mo ago
The IPv2 to IPv4 migration involved sysadmins at less than 50 institutions (primarily universities and research labs), updating things they considered to be a research project, that didn’t have specialised network hardware that knew anything about IP, and any networked software was primarily written either by the sysadmins themselves or people that one of them could walk down the corridor to the office of. Oh, and several months of downtime if someone was too busy to update right now was culturally acceptable. It’s not remotely the same environment as existed at the time of IPv6 being designed

almosthere 10mo ago

The IPv4+ could pass through a router that doesn't know about it - the cloud host that receives that packet could interpret it in a special way, in fact you could stuff additional data into the next layer of the stack for routing - it's not like many services beyond TCP would need to support the scheme.

viraptor 10mo ago
> The IPv4+ could pass through a router that doesn't know about it It couldn't do that reliably. We don't have any flags left for that that. Options are not safe. We've got one reserved flag which is anyways set to 0, so that's not safe either.
- magicalhippo 10mo ago
  > We don't have any flags left for that that. There's the reserved bit (aka the evil bit[1]). Are you saying gear out there drops packets with reserved bit set to 1? Wouldn't surprise me, just curious. Seems like IPv4+ would have been a good time to use that bit. Any IPv4+ packets could have more flags in the + portion of the header, if needed. [1]: https://en.wikipedia.org/wiki/Evil_bit https://en.wikipedia.org/wiki/Evil_bit
  - viraptor 10mo ago
    That bit is currently defined as "Bit 0: reserved, must be zero", so there will be network gear out there, that either drops the packet otherwise or resets the bit to 0 when forwarding.
    - magicalhippo 10mo ago
      That makes it effectively impossible to ever use then, so a waste of a bit. Too bad they made that mistake when writing the spec. Would have been better if they specified it like most APIs, ie ignore if you get it, carry it if you forward, and set it to zero if you send it.

morshu9001 10mo ago

Hardware support for ipv6 hasn't been the limiting factor in a long time. Users higher on the stack don't want to adopt something that makes so many unnecessary changes.

solarkraft 10mo ago

You’re focusing on the technical difficulty of implementing it in software. This is not the problem. IPv6 support is now present in almost every product, but people still refuse to set it up because it’s so different to what they’re used to (I’m not arguing whether the changes are good - they’re just changes). IPv4+ would’ve solved this social problem.

doctorpangloss 10mo ago
There’s absolutely, utterly zero chance IPv4+ would be adopted. CGNAT is the solution to the social problem. I don’t even buy your way of thinking - unlike an “engineering” solution or an “incentives” solution, the problem with “social solutions I speculate about” is: they offer nothing until implemented. They are literally all the same, no difference between the whole world of social solutions, until they are adopted. They are meaningless. They’re the opposite of plans. Like what’s the difference between IPv4+, which doesn’t exist, and “lets pass a law that mandates ipv6 support”? Nothing. This is what the mockery of “just pass a law” is about. I don’t like those guys, but they are right: it’s meaningless.
- solarkraft 10mo ago
  This is a good point. The same “why should I migrate” would affect it. However, it being so close to the predecessor, it would be much easier to do so, catching way more people who are on the fence.