Discussion
Ankshilp
lgunsch: If IPv6 was going to be successful, it would have been successful years ago. It seems, people are just more comfortable with layers of NAT than native IPv6 everywhere. I'd guess that it should have been more backwards compatible. Similar to UTF-8 and ASCII.
mono442: The main problem with IPv6 is that it is different from IPv4. There's SLAAC, there's no ARP and there're also some other differences. In the end, it's simpler to just not bother.
azalemeth: I am behind cgnat but have a native ipv6 /64 at home. I've got a great fibre connection (2G5) and everything "just works". I can host on ipv6 native machines and see them from anywhere in the world that has native ipv6 access.The trouble is that 1) my employers do not have native ipv6 access; 2) neither does my mobile connection; and 3) really nor do a lot of my friends. Moreover, 4) if you browse a website from a native world-reachable ipv6 address, you're fingerprinted by it and it's overwhelmingly unique to you. So, it doesn't really work for hosting, and I don't get any direct benefits from it.Instead I have a vps with a public ipv4 address and have a router that creates a wireguard tunnel to it. The reverse proxy works great over ipv6 and I am now in a position where I can forward ports and have direct connections -- albeit with hugely increased technical complexity. Ipv6 has many great ideas in it. If it's universally used it might just catch on...
jdwithit: IPv4 has been "in crisis" for the entire 20 years I've worked in tech and we seem to be managing alright. Not to say things can't be better or we shouldn't try to improve. But I'll be surprised if v4 isn't still the default for most use cases in another 20 years.
RiverCrochet: That's because the Internet is basically broadcast TV 2.0 so no one cares about having public IPv4's at home as long as they can get to their memes and streaming. Great job, we took something that was meant to be a next frontier in humanity and let anyone connect with anyone else without gatekeepers/intermediaries and turned it 21st century brainrot troughs. Perhaps a society not in slow intellectual decline would have chosen otherwise.
isodev: Someone should’ve thought about the UX of IPv6 before declaring it to be “the way”. It’s like having to learn Klingon just to setup your printer. IPvNext could sort that out… maybe it’s time to consider moving on.
wmf: No mention of Indian ISPs just buying IPv4 addresses. Prices are even declining.
rectang: If UTF-8 represents the triumph of a design prioritizing backwards compatibility with an existing standard (ASCII) to facilitate a transition, then IPv6 is the cautionary tale of a design which could have made the transition simpler but did not.
w3ll_w3ll_w3ll: IPv6 cannot be backward-compatible with IPv4 in the way UTF-8 is with ASCII. Any argument built on that comparison reflects a misunderstanding of the protocols and leads to flawed conclusions.
lern_too_spel: His point is that you're managing alright because you live in a country where your ISP can give you a public IP address. The author lives in a country where that is not possible and accesses the Internet behind layers of NAT.
LoganDark: What's the difference, other than port forwarding? Does NAT cause some sort of unique issue that makes existence miserable?
IsTom: Like there was any chance to see UX of this to work or not in most of places. I've never had an ISP that even offered any IPv6 connectivity besides mobile internet.
tonymet: > There are countless threads online on forums like Hacker News, Reddit where people who never really got comfortable with idea of IPv6It’s clumsier than ipv4. It’s unnecessary since NAT was invented. In practice IPv6 requires dual stack, which means twice as many firewalls, names and routes to manage — so 4x the debugging because you have 2 dimensions that can either be working or failing. Addresses are too long to remember, too clumsy to write, and after 30 years still don’t have consistent representation (how many colons and brackets?).Look, IPv6 has some benefits, but until the usability is fixed, it will be another 30 years before it’s close to 95% adoption.
apearson: To reduce doing things twice there is NAT64/646XLAT. How many v4 addresses have you memorized, I normally use DNS or mDNS.
oconnore: I don't understand why people are so negative about IPv6. I have done essentially zero home networking work and I just ran this successfully. It just works!``` > ping6 google.com PING6(56=40+8+8 bytes) 2605:59c0:236f:3a08:7883:9d04:c26d:5fa1 --> 2607:f8b0:4005:806::200e 16 bytes from 2607:f8b0:4005:806::200e, icmp_seq=0 hlim=117 time=22.262 ms 16 bytes from 2607:f8b0:4005:806::200e, icmp_seq=1 hlim=117 time=26.124 ms 16 bytes from 2607:f8b0:4005:806::200e, icmp_seq=2 hlim=117 time=26.807 ms ^C --- google.com ping6 statistics --- 3 packets transmitted, 3 packets received, 0.0% packet loss round-trip min/avg/max/std-dev = 22.262/25.064/26.807/2.001 ms ```
ux266478: > Great job, we took something that was meant to be a next frontier in humanity and let anyone connect with anyone else without gatekeepers/intermediariesWe already had that, it's called shortwave radio. The internet, especially as it's implemented and as it's used, is a terrible way to achieve this. It's service providers the whole way down.
smallmancontrov: It would be funny if HAM radio came back because the social filter imposed by the limitations wound up being more important than the technological capability.
bluGill: People claim this all the time, but every time I push I discover they have no clue how networks work and just handwave away as "easy" or "details" the very reasons people who understand networks say it can't work.
isodev: I think you’re making my point - someone decided to surface a very low level concept “as is” (without a suitable abstraction) on a level where people also need it for use cases that don’t justify knowledge of the arcane. Or dealing with gatekeepers for that matter.
bluGill: For most people there is no UX. Most US houses are IPv6 and use it without knowing anything about networking at all (most cable internet is IPv6, as the big cell networks).The people who have to make networks work need to know how IPv6 works - but there is no getting around that - they know how IPv4 works too.
j1elo: Why not? Sincere question. As a very superficial idea, if we go back to the drawing board, for example we could decide our new cool concept of address to be an IPv4 + an hex suffix, maybe at the expense of not having a humongous address space.So 10.20.30.40 would be an IPv4 address, and 10.20.30.40:fa:be:4c:9d could be an IPv6 address. With the :00:00:00:00 suffix being equivalent to the IPv4 version.I just made this up, so I'm sure that a couple years of deep thought by a council of scientists and engineers could come up with something even better.
IsTom: How do you squeeze that in IPv4 packet? Especially in a way that won't get mangled by random ossified devices in between?
AussieWog93: Wait, why couldn't it?Just split the address into two 32-bit chunks (call the top word the "pool", bottom word "address") and assign the full IPV4 range to pool 0x00000000. Done.
treyd: Well for starters, IPv6 has 128 bit addrs.But then think about what the routing tables would look like, how would an IPv4-only host find an IPv6 host not in pool 0? You'd be reinventing NAT, but in a less-structured context than how NAT works today. There's more issues to it too.If it was really that simple they would have done exactly that. "Just adding more bits to IPv4" just isn't possible to do backwards-compatibly. IPv6 is the closest you can get to that while also dealing with the complexity that arises with longer addresses.
thomasdziedzic: IPv6 feels like we just can't admit to ourselves that it has been a failed transition. What would it take to come up with IPv7 which takes in the lessons of IPv6 and produces something better that we can all agree is worth transitioning to over IPv4.
apearson: What changes to IPv6 would you make to make it easier to transition?
gmuslera: It is the only way forward, but the reason for that is not the correlation between population and IP addresses. After all, most of the use of internet today is not by people, but by bots, crawlers, AI agents, b2b and more, and that is far more than the human population, and then you have the virtual networks built over IP like VPNs, Tor and more. It is more related to privacy, bidirectional communication and protocols, security, identity and possibilities.
SkiFire13: How would you get someone that only knows about IPv4 addresses like 10.20.30.40 to send a packet to someone with an address 10.20.30.40:fa:be:4c:9d?
Chu4eeno: ... and annoying casting from `sockaddr` to either `sockaddr_in` or `sockaddr_in6*` while you pass around a socklen_t.10 years ago I was all gung-ho about IPv6, but it's annoying at every level.
tonymet: Having 2 sockets for loopback or multiple interfaces is a huge pain
Yizahi: I honestly don't understand why IPv6 is not actively deployed in 2026. Every piece of networking hardware over past decade supports IPv6 and often dual stack too. And to switch between both often takes a few clicks if DHCPv6 server is up and reachable. Absolutely transparent, free, zero performance hit. But no, so many persist at doing v4.PS: I'm talking about MSO hardware. But client hardware should be at the same level of compatibility for years too.
thomasdziedzic: 2026: $ ping6 github.com ping6: github.com: Address family for hostname not supported
AussieWog93: >how would an IPv4-only host find an IPv6 host not in pool 0?Ah.
Bender: The only place I have utilized an IPv6 address is on my authoritative name servers only because some DNS testing tools assume it is there. It's not really needed however. My home firewall does have one but I have never used it. I can't think of a use for it. I have multiple static IPv4 addresses and they have suited me just fine for decades. I suppose I could bind a Squid SSL Bump MitM proxy to it in case a site blocks me but I would probably leave it off most of the time.I never use them on my web, chat, voice, IRC and other servers as I personally find blocking shenanigans on IPv4 and not having to implement the same checks on IPv6 is just easier for a lazy person like me. IPv6 just feels like an after-thought bolt on to me. Clunky, not well thought out. Some privacy gotchas that can be disabled but some will not. That's just my take. I doubt anyone will have the same take. I think IPv4 will be fine for another 100 years even if we have to re-purpose some DoD/MoD ranges given they don't use them and maybe annex some /8's from a few greedy companies. But that's a problem for Gen Delta. Gen Foxtrot can deal with repurposing some multicast ranges.
jmyeet: I find it fascinating how these key technologies handle upgrades and breaking changes. For example, Python eschewed breaking changes through 2.7.x but the dam has burst since 3.0 and every point release (it seems?) makes breaking changes, sometimes reversing itself (eg the whole s/u string prefix thing).Many here will be familiar with the second system effect [1]. Usually people want to avoid making breaking changes but once they do, they can go a little nuts. My personal opinion is only major versions should make breaking changes and a lot of thought should go into making them as painless as possible.IPv6 is fascinating for these reasons but also that it's a product of its time in two main ways:1. It doesn't do anything about roaming because that wasn't an issue in the 1990s but it certainly is now;2. A 64 bit address space would've basically been infinite addresses but instead they went with 128 bit addresses (rolling in ports) but then giving individual users a /64 address range. For some reason people deny it now or simply weren't aware but that too is a historical artifact because it was intended to put a 48 bit MAC address into that space but later we realized that's a huge PII and tracking issue; and3. History has shown that upgrading network backbone hardware (in particular) is incredibly difficult through a process that's been described as "ossification", which is a nice description. Basically, network relays and routers wanted to avoid security issues and decided to discard things they didn't understand.That's interesting because it violates Postel's Law [2], which basically says be liberal in what you accept and conservative in what you send.But this shows up in all sorts of interesting ways, like it's practically impossible to reliably use MTUs larger than about 1536. When IPv4 was designed, that wasn't an issue. With 1-100G+ networks it is. There are RFCs about using large MTUs but you're dependent on backbone hardware you have no control over.Even Linux struggles with this, to the point where you need to do some configuration for high-bandwidth networks (eg RPS [3]). Just handling all those interrupts presents a bunch of problems beyond the original scope. And again, it's hard to fix through no fault of Linux's.I'm old enough to remember the talk about us running out of IPv4 addresses back in the 1990s. It's been interesting to watch how this has consistently been kicked down the street (eg cgNAT).What is funny though is large companies (eg Facebook) actualy ran out of internal addresses on a 10/8 network and there's no good solution for that (with IPv4 at least).[1]: https://en.wikipedia.org/wiki/Second-system_effect[2]: https://en.wikipedia.org/wiki/Robustness_principle[3]: https://lwn.net/Articles/362339/
jcgl: > 3. History has shown that upgrading network backbone hardware (in particular) is incredibly difficult through a process that's been described as "ossification", which is a nice description. Basically, network relays and routers wanted to avoid security issues and decided to discard things they didn't understand.What makes you suggest that it's backbone hardware that is the problem? It's largely enterprise customers and tier 3 providers that don't really do IPv6 afaics.
flumpcakes: One of the biggest, I would assume in the current year, blockers to an IPv6 only world would be the fact that the major "cloud" vendors do not support it.
throw0101c: > What's the difference, other than port forwarding? Does NAT cause some sort of unique issue that makes existence miserable?The difference is that your home router does not get a public IP on its WAN interface, but perhaps 100.64.0.0/10 [1] with CG-NAT.So if you don't have a public IP address, how exactly are you supposed to forward anything? What is the other end supposed to connect to as an IP address?[1] https://en.wikipedia.org/wiki/IPv4_shared_address_space
plqbfbv: > What would it take to come up with IPv7 which takes in the lessons of IPv6 and produces something better that we can all agree is worth transitioning to over IPv4.The only lesson to learn from IPv6 deployment is that if there's a workaround available and the world isn't burning, it'll take 30 years from initial design to actual adoption. So if you went out and took 10 years to design IPv7, it'd likely take until 2070 for it to gain some adoption. This is because big network hardware is costly and has very long replacement cycles.IPv6 was already designed as a lessons-learnt protocol from IPv4 issues. The header is greatly simplified and it's more hardware-friendly, it incorporates the required features into the protocol and leaves extensibility as an optional add-on that doesn't slow down routing packets, all the while granting an infinite address space.
