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Agreed. Python 3 and IPv6 are case studies in how not to do an upgrade. While I can appreciate the care and engineering skill involved in upgrading a technolog

Agreed. Python 3 and IPv6 are case studies in how not to do an upgrade. While I can appreciate the care and engineering skill involved in upgrading a technology while still having backward compatibility, it turns out just to enable the worst possible behavior on the consumer end. I think I like Apple's way of just forcing breaking changes down everyone's throats (e.g. removing CD/DVD, PowerPC->x86, 30-pin->Lightning, dropping headphone port, etc.). Sure the tech media complain for a cycle, but then everybody adapts and the world's a better place.

XorNot 5y ago
There was literally no choice when it came to IPv6. Everyone who thinks they've got a clever compromise is forgetting that it's not a software problem where it matters.
- drran 5y ago
  Embrace Extend Extinguish I vote for IPv5 protocol, which will allow to cal any IPv4 host via IPv5-IPv4 NAT transparently at nearest bridge. WHY I cannot do `ping6 127.0.0.1`? WTF? Is IPv6 is too small for whole IPv4 address space?
  - tialaramex 5y ago
    You've listed a command line you'd like to run, but have you spent any time to decide what it is that you think it should actually mean? Maybe you think it should just be exactly equivalent to ping6 ::1 - your ping6 could be updated to allow this but, like, why? That's not an improvement at all. OK, so maybe it should be equivalent to ::127.0.0.1 - but that's very strange, an operating system could choose to have this do what you expect locally but it's not clear to what end and again it doesn't offer any wider improvement. IPv6 is big enough that it contains the entire IPv4 address space - in several different places in fact although ::a.b.c.d is the most transparent. But, that's completely irrelevant to the problem, which I suspect means you still haven't quite grasped what the problem even is.
    - slownews45 5y ago
      You're wrong here. Folks actually deploying wanted better co-existence options for folks on IPv6, and it's shown up. You basically route ipv6 as IPv6 until you hit a network border that doesn't support IPv6, then go over to IPv4 for the rest. This let's me do IPv6 only devices without giving up IPv4. As it is, they locked the upgrade cycle, because you can't do IPv6 only without losing access to IPv4 (historically). In the end folks did get work arounds going using 464XLAT https://datatracker.ietf.org/doc/html/rfc6877 https://datatracker.ietf.org/doc/html/rfc6877
    - drran 5y ago
      I expected (20+ years ago), that IPv6 address space will be extension of IPv4 address space, so `ping6 IPv4_ADRESS` will use IPv4 protocol internally, bind6(IPv4_ADDRESS, IPv4_PORT) will use IPv4 socket internally, and so on. It's easy to implement: an_ipv6_function(address) { if (address & 0xffffffffffff0000 == 0) { // Use legacy ipv4 protocol ... } else { // Use modern ipv6 protocol ... } } Actual result: I cannot ping an ipv4 address using an ipv6 tool, or connect to an ipv4 server using an ipv6 only tool.
      - cesarb 5y ago
        That already exists, it's called an "IPv4-mapped address". The IPv4 address 198.51.100.15 can be represented in IPv6 as ::ffff:c633:640f (normally shown as ::ffff:198.51.100.15). See in particular at https://man7.org/linux/man-pages/man7/ipv6.7.html https://man7.org/linux/man-pages/man7/ipv6.7.html the IPV6_V6ONLY option which can be used to disable that mapping.
        drran 5y ago
        Yes, I know about this mapping (I can read man pages too), but a) ping6 ::ffff:127.0.0.1 doesn't work too; b) it's not an IPv4 address, because the binary representation of ::ffff:127.0.0.1 != 127.0.0.1. It's the IPv4 address space mapped to an IPv6 address space (IPv4-mapped-on-IPv6). c) IPv4 addresses in IPv6 address space are deprecated: https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.5.1 https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.5.... . In short, IPv6 and IPv4 cannot coexist, so they must be separated, so we must keep IPv4, because it's mandatory, and we may skip IPv6, because it's optional. So, all internet providers in my area are skipping IPv6, because they can. All that problems are created by lack of backward compatibility in IPv6 protocol. Why? «Because backward compatibility with IPv4 is unnecessary. IPv6 is so much better. Everyone will jump to IPv6 till end of the next (1995) year.»
  - dcow 5y ago
    Why not IPv10?
- tialaramex 5y ago
  Right. The specific problem is that 2^32 isn't enough. The most naive "solutions" were from people who hadn't even recognised why it's 2^32. For example, let's just have numbers bigger than 255 between the dots ... why can't we do that? But once you get past those, another layer of "solutions" see the immediate technical consequences of 2^32 not being enough but don't grok the bigger picture. For example let's just turn existing 32-bit IP addresses into a 64-bit IPng address by adding zeroes, and then all the old addresses are now networks with up to 4 billion nodes. But wait, all those addresses are assigned too now, so we still have an address shortage. Oops. The least stupid people saw the new address scheme itself as logical but just felt like surely IPv6 should have resisted the urge to fix anything else. Sure, you're embarking on a multi-decade project that likely cannot ever be repeated, but let's just leave all the sharp edges and weird anomalies exactly as they are to minimise upgrade costs. This belief is less stupid, but it is still pretty stupid, that cost difference is a drop in the bucket, and this was our only chance to fix some pretty huge mistakes made when the Internet was newborn. It would actually be cheaper for a lot of big outfits to go IPv6-only today (and then use edge translators) than drag their heels and try to stay on IPv4 as long as possible, but contrary to popular belief almost nobody really does "cost-benefit analysis" to decide what to do - they make a decision based on emotion and any such analysis is purely there to support that decision. Buying more addresses is a budget line item you can see, but a lot of big IPv4 costs are hidden in existing practices that "always" have cost money but would vanish under IPv6, and some IPv6 costs are only there if you did no preparation. If you just count the need to replace those IPv4-only printer-copiers you purchased a year ago across the company, and forget that you intentionally chose not to ask bidders if they were IPv6 capable you're going to persuade yourself that it's cheaper to keep waiting.
- toast0 5y ago
  IPv6 could have been a straight forward expansion of the address field without replacing ARP (which could easily have been extended for v6 addresses, just need to define an address type value) and header processing and address autoconfig and X and Y and Z. It still would have taken a long time to deploy, because you still need hardware and software support in lots of places, but it might have been a little less long, and a little less bad along the way. I don't think we got much of use from the new ways either. I can announce IPv6 ranges to my LAN from two different ISPs, but my clients will use an IP from one and send to the gateway from the other, so that doesn't help me.
  - tialaramex 5y ago
    ARP is a broadcast protocol, so that's pretty bad news, whereas IPv6 Neighbour Discovery gets to use (link local) multicast. On the cheapest budget cobbled together network, either one turns into a network broadcast. But even a bargain basement 1990s Ethernet chipset does onboard multicast filtering, so irrelevant neighbour discovery packets needn't wake up your OS whereas every ARP query must be drawn to the attention of every host's OS to confirm it's not for them. However, spend a little more money and the network switch understands multicast, so now the data isn't even sent across links which don't have anybody listening to that address, whereas of course nothing can be done about broadcasts. You couldn't have easily done this trick in IPv4 because the address space is too small, but in IPv6 choosing the Ethernet multicast addresses to make this work falls out very easily.
kungito 5y ago
I feel like Apple's way of forcing is because you cannot buy new Apple products with old features. In software you can keep using the old version and complain about the new one. This problem is especially visible in poorly designed ecosystems like Go and Python. Do you think introducing generics to a language like Go won't cause a great divide in the community? Sure, it won't be a breaking change but it will still divide people into the "old way" and "new way" camps. I guess the language which changed the most along the years without breaking things is C# but then again .NET actually introduced a lot of breaking changes unrelated to the C# language.
- pjmlp 5y ago
  Bad example actually. Lots of us on Windows are still stuck with .NET Framework, because no matter how Microsoft keeps pushing it, even their own products aren't fully ported to Core, let alone 3rd parties.
  - kungito 5y ago
    That's what I said as well. C# good, .NET bad
    - pjmlp 5y ago
      One doesn't go without the other.
jacquesm 5y ago
Ah, and don't forget FireWire.
ajsnigrutin 5y ago
IPv6 is great... the only problem is, that IPv4 has be patched enough with workarounds, to make IPv6 unecessary for most "normal users", and there is nothing to sell there. Yes, a simple voice call might use STUN, through two nats, fail to puncture a hole, and then be proxied over a server somewhere, but "it works". Noone is willing to may 1$/€ more per month to get IPv6, noone really needs it, half of IoT doesn't support it (ahem, esp8266/32), it's costly to implement and costly to educate users (especially those, relying on nat for "security"). Most of the IPv6 progress is because the governments mandate it for many stuff, big cloud providers are running out of addresses to buy, vendors want to sell new routers and switches... basically, everybody except the users.

XorNot 5y ago

There was literally no choice when it came to IPv6. Everyone who thinks they've got a clever compromise is forgetting that it's not a software problem where it matters.

drran 5y ago
Embrace Extend Extinguish I vote for IPv5 protocol, which will allow to cal any IPv4 host via IPv5-IPv4 NAT transparently at nearest bridge. WHY I cannot do `ping6 127.0.0.1`? WTF? Is IPv6 is too small for whole IPv4 address space?
- tialaramex 5y ago
  You've listed a command line you'd like to run, but have you spent any time to decide what it is that you think it should actually mean? Maybe you think it should just be exactly equivalent to ping6 ::1 - your ping6 could be updated to allow this but, like, why? That's not an improvement at all. OK, so maybe it should be equivalent to ::127.0.0.1 - but that's very strange, an operating system could choose to have this do what you expect locally but it's not clear to what end and again it doesn't offer any wider improvement. IPv6 is big enough that it contains the entire IPv4 address space - in several different places in fact although ::a.b.c.d is the most transparent. But, that's completely irrelevant to the problem, which I suspect means you still haven't quite grasped what the problem even is.
  - slownews45 5y ago
    You're wrong here. Folks actually deploying wanted better co-existence options for folks on IPv6, and it's shown up. You basically route ipv6 as IPv6 until you hit a network border that doesn't support IPv6, then go over to IPv4 for the rest. This let's me do IPv6 only devices without giving up IPv4. As it is, they locked the upgrade cycle, because you can't do IPv6 only without losing access to IPv4 (historically). In the end folks did get work arounds going using 464XLAT https://datatracker.ietf.org/doc/html/rfc6877 https://datatracker.ietf.org/doc/html/rfc6877
  - drran 5y ago
    I expected (20+ years ago), that IPv6 address space will be extension of IPv4 address space, so `ping6 IPv4_ADRESS` will use IPv4 protocol internally, bind6(IPv4_ADDRESS, IPv4_PORT) will use IPv4 socket internally, and so on. It's easy to implement: an_ipv6_function(address) { if (address & 0xffffffffffff0000 == 0) { // Use legacy ipv4 protocol ... } else { // Use modern ipv6 protocol ... } } Actual result: I cannot ping an ipv4 address using an ipv6 tool, or connect to an ipv4 server using an ipv6 only tool.
    - cesarb 5y ago
      That already exists, it's called an "IPv4-mapped address". The IPv4 address 198.51.100.15 can be represented in IPv6 as ::ffff:c633:640f (normally shown as ::ffff:198.51.100.15). See in particular at https://man7.org/linux/man-pages/man7/ipv6.7.html https://man7.org/linux/man-pages/man7/ipv6.7.html the IPV6_V6ONLY option which can be used to disable that mapping.
      - drran 5y ago
        Yes, I know about this mapping (I can read man pages too), but a) ping6 ::ffff:127.0.0.1 doesn't work too; b) it's not an IPv4 address, because the binary representation of ::ffff:127.0.0.1 != 127.0.0.1. It's the IPv4 address space mapped to an IPv6 address space (IPv4-mapped-on-IPv6). c) IPv4 addresses in IPv6 address space are deprecated: https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.5.1 https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.5.... . In short, IPv6 and IPv4 cannot coexist, so they must be separated, so we must keep IPv4, because it's mandatory, and we may skip IPv6, because it's optional. So, all internet providers in my area are skipping IPv6, because they can. All that problems are created by lack of backward compatibility in IPv6 protocol. Why? «Because backward compatibility with IPv4 is unnecessary. IPv6 is so much better. Everyone will jump to IPv6 till end of the next (1995) year.»
- dcow 5y ago
  Why not IPv10?
tialaramex 5y ago
Right. The specific problem is that 2^32 isn't enough. The most naive "solutions" were from people who hadn't even recognised why it's 2^32. For example, let's just have numbers bigger than 255 between the dots ... why can't we do that? But once you get past those, another layer of "solutions" see the immediate technical consequences of 2^32 not being enough but don't grok the bigger picture. For example let's just turn existing 32-bit IP addresses into a 64-bit IPng address by adding zeroes, and then all the old addresses are now networks with up to 4 billion nodes. But wait, all those addresses are assigned too now, so we still have an address shortage. Oops. The least stupid people saw the new address scheme itself as logical but just felt like surely IPv6 should have resisted the urge to fix anything else. Sure, you're embarking on a multi-decade project that likely cannot ever be repeated, but let's just leave all the sharp edges and weird anomalies exactly as they are to minimise upgrade costs. This belief is less stupid, but it is still pretty stupid, that cost difference is a drop in the bucket, and this was our only chance to fix some pretty huge mistakes made when the Internet was newborn. It would actually be cheaper for a lot of big outfits to go IPv6-only today (and then use edge translators) than drag their heels and try to stay on IPv4 as long as possible, but contrary to popular belief almost nobody really does "cost-benefit analysis" to decide what to do - they make a decision based on emotion and any such analysis is purely there to support that decision. Buying more addresses is a budget line item you can see, but a lot of big IPv4 costs are hidden in existing practices that "always" have cost money but would vanish under IPv6, and some IPv6 costs are only there if you did no preparation. If you just count the need to replace those IPv4-only printer-copiers you purchased a year ago across the company, and forget that you intentionally chose not to ask bidders if they were IPv6 capable you're going to persuade yourself that it's cheaper to keep waiting.
toast0 5y ago
IPv6 could have been a straight forward expansion of the address field without replacing ARP (which could easily have been extended for v6 addresses, just need to define an address type value) and header processing and address autoconfig and X and Y and Z. It still would have taken a long time to deploy, because you still need hardware and software support in lots of places, but it might have been a little less long, and a little less bad along the way. I don't think we got much of use from the new ways either. I can announce IPv6 ranges to my LAN from two different ISPs, but my clients will use an IP from one and send to the gateway from the other, so that doesn't help me.
- tialaramex 5y ago
  ARP is a broadcast protocol, so that's pretty bad news, whereas IPv6 Neighbour Discovery gets to use (link local) multicast. On the cheapest budget cobbled together network, either one turns into a network broadcast. But even a bargain basement 1990s Ethernet chipset does onboard multicast filtering, so irrelevant neighbour discovery packets needn't wake up your OS whereas every ARP query must be drawn to the attention of every host's OS to confirm it's not for them. However, spend a little more money and the network switch understands multicast, so now the data isn't even sent across links which don't have anybody listening to that address, whereas of course nothing can be done about broadcasts. You couldn't have easily done this trick in IPv4 because the address space is too small, but in IPv6 choosing the Ethernet multicast addresses to make this work falls out very easily.

kungito 5y ago

I feel like Apple's way of forcing is because you cannot buy new Apple products with old features. In software you can keep using the old version and complain about the new one. This problem is especially visible in poorly designed ecosystems like Go and Python. Do you think introducing generics to a language like Go won't cause a great divide in the community? Sure, it won't be a breaking change but it will still divide people into the "old way" and "new way" camps. I guess the language which changed the most along the years without breaking things is C# but then again .NET actually introduced a lot of breaking changes unrelated to the C# language.

pjmlp 5y ago
Bad example actually. Lots of us on Windows are still stuck with .NET Framework, because no matter how Microsoft keeps pushing it, even their own products aren't fully ported to Core, let alone 3rd parties.
- kungito 5y ago
  That's what I said as well. C# good, .NET bad
  - pjmlp 5y ago
    One doesn't go without the other.

jacquesm 5y ago

Ah, and don't forget FireWire.

ajsnigrutin 5y ago

IPv6 is great... the only problem is, that IPv4 has be patched enough with workarounds, to make IPv6 unecessary for most "normal users", and there is nothing to sell there. Yes, a simple voice call might use STUN, through two nats, fail to puncture a hole, and then be proxied over a server somewhere, but "it works". Noone is willing to may 1$/€ more per month to get IPv6, noone really needs it, half of IoT doesn't support it (ahem, esp8266/32), it's costly to implement and costly to educate users (especially those, relying on nat for "security"). Most of the IPv6 progress is because the governments mandate it for many stuff, big cloud providers are running out of addresses to buy, vendors want to sell new routers and switches... basically, everybody except the users.