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Comment by ghshephard | Hacker News Reader

At some point, some low-hanging companies are just going to start running IPv6 only applications and deal with the fall-out of some nn% of their customer not being compatible. Those customers will complain to their ISPs, which will provide incentive to get IPv6 deployed (should have been done 10 years ago honestly at any credible ISP). Getting the number closer to 100% will make it easier for new companies to deploy IPv6 only, until we get to the point that IPv4 is seen as some legacy thing that isn't relevant but used to be important in the dark ages of Web Deployments.

I'm very surprised at work and at home how often most of my Internet communications is running over IPv6. There are some surprising exceptions though [1].

I'd be willing to place a wager that there will be a $100mm company that is only IPv6 by 2030. And that the "Default IPv6 only on the Internet unless there is some weird edge case" will occur by 2040.

IPv4 as a protocol, though, will never, ever, go away - we'll see it widely deployed for the next 100 years.

[1]

    $ dig news.ycombinator.com AAAA

   ; <<>> DiG 9.16.1-Ubuntu <<>> news.ycombinator.com AAAA
   ;; global options: +cmd
   ;; Got answer:
   ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46616
   ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

   ;; OPT PSEUDOSECTION:
   ; EDNS: version: 0, flags:; udp: 65494
   ;; QUESTION SECTION:
   ;news.ycombinator.com.          IN      AAAA

   ;; Query time: 176 msec
   ;; SERVER: 127.0.0.53#53(127.0.0.53)
   ;; WHEN: Thu Dec 09 15:21:09 EST 2021
   ;; MSG SIZE  rcvd: 49

View on HN

That’s an easy bet to make, as today $100m is late-seed, pre-launch valuation for any company that promises both AI and blockchains.

Assuming company valuations continue to inflate, by 2030 $100m goes to any team who manage to agree on a business card design

IPv6 is a disaster. It's too difficult to understand or configure properly, and it's too different from IPv4. There is a ton of software that breaks with IPv6, and a ton of system administrators that doesn't understand it (and for a reason, it's too complicated for nothing).

I would have preferred an IPv4 version 2, and extension to the address space of IPv4, possibly in a backward compatible way, so that applications, routers and equipment not built for the new protocol can continue to work, of course considering only a part of the address (e.g. if the network passes trough some old routers, it's not a problem since they only have to look at the most significant part of the address that is in the same place of the IPv4 address) and can ignore the extension.

Having a dual stack network is also a mess, and I don't get how it was considered a good idea. IPv4 this way will never go away, and we will always have two network stacks on every computer. And if you have to choose between two, you will choose the easier one, or the one you know, that is IPv4. A simple extension would have been far more easier to rollout.

> possibly in a backward compatible way

Pre-IPv6 all IP code had 32 bits reserved for addresses. For more addresses, you would need >32 bits.

How do you squeeze >32 bits of data into 32 bit data structures?

You would need to touch every bit of IP code out there to expand the corresponding address filed (e.g., in a struct in_addr)—which is what had to be done for IPv6.

I'd argue that that's in essence what NAT (especially CGNAT) does by abusing the 16 bit port number: extend the 32-bit assessing space to ~48 bits. And it pretty much works just fine for many many use cases.

Because NAT is really pervasive basically only the use cases that work with it survived.

* https://en.wikipedia.org/wiki/Survivorship_bias

Because a whole suite of protocols had to be invented:

* https://en.wikipedia.org/wiki/STUN

* https://en.wikipedia.org/wiki/Traversal_Using_Relays_around_...

* https://en.wikipedia.org/wiki/Interactive_Connectivity_Estab...

See also "NAT Issues when playing games":

* https://support.plume.com/hc/en-us/articles/360035745134-NAT...

Certainly we'd need hole punching protocols (UPnP/PCP) because IPv6 firewalls would be default deny on incoming connections, but the addressing issue introduces a bunch of things on top of that. The fact that these kludges are considered 'normal' and/or 'okay' is kind of sad.

And how do you hole punch through CGNAT? (AFAIK there is no way.)

Everything is being crammed into HTTP/QUIC/whatever because of all of these limitations: what applications could have been designed better if bits flowed more freely? (SCTP and DCCP died because of limited middleware network boxes.)

As the TRUN article says, only the symmetric NAT is impregnable, you can punch holes through other types on NAT.

For home users and non-professionals, IPv6 is simpler than IPv4. Every device autoconfigs selecting its own address via SLAAC. No DHCP needed. No need to understand NAT and no dealing with subnets.

Especially when mDNS is in the mix and every device gets its own .local domain, which already happens with iOS, macOS and Windows devices (plus Linux with avahi), it is dead simple to have a very reliable local network.

Ditching Ethernet broadcast that hit every single interface on a network when you only wanted to communicate with a single device on a specific protocol is a big win. Getting rid of Subnets by making the smallest possible subnet infinitely large eliminated 90% of network confusion around subnets. Privacy based IP addresses also a nice addition. After working with IPv6 for 10 or so years, you really grew to appreciate what an architectural advantage it has over IPv4. As for deploying it? I dunno - I just plug my Ubuntu laptop into a WiFi Network and it just seems to work. I'm pretty sure the comcast routers I've connected to have had zero configuration beyond what they can pick up connecting to comcast. In the future - people (other than say Network Engineers working for IT) probably won't even discuss things like "IP" addresses.

So, a common home setup is to plug a fancy router behind the ISPs useless modem router.

What happens is, IPv4 works out of the box. IPv6 doesn't work, because the fancy router doesn't get a big enough subnet from the useless ISP modem.

My piece of shit useless ISP modem/router (from Spectrum, one step sideways from Comcast in quality) supports IPv6 out of the box. 0 effort.

Getting it to stay working for an entire week without a reboot? Seems to be impossible. But IPv6 just works.

Yeah. My useless ISP router supports it as well here. But it doesn't work when there's a second router in between. Something to do with Prefix Delegation not working, supposedly. And the ISP router by itself has zero controls for IPv4 DHCP, and so on, so it's absolutely useless by itself.

My ISP just rolled out IPv6 a couple of weeks ago. I was pretty excited until I learned WSL2 doesn’t support IPv6.

IPv6 isn't all that difficult, insomuch as IPv4 is not basic itself. In fact it's probably easier to teach someone with no prior knowledge IPv6 instead of IPv4. "What's the netmask" isn't a question for user endpoints, it's /64. You can still DHCP, you can still hardcode, but the replacement for ARP can also assign you an IP without having to configure external services to make that happen.

The IPv4 header and the way routers work wouldn't allow for a variable address. The source/destination sit in front of variable length extensions and the actual payload. Not to mention it'd be god awful to implement that kind of thing in non programmable level hardware. You could always implement it as an option header but then you've basically invented "v6 over v4" which is already a thing. Of course there is always NAT which v4 endpoints are already used to so this is a non-problem anyways, I've run v6 only at home for years at this point.

A lot of applications break on it sure but that's because a lot of applications are hardcoded with the assumptions about how big the address is not because the address gets put into a container named "v6" instead of "v4 version 2" by the OS.

> Not to mention it'd be god awful to implement that kind of thing in non programmable level hardware.

Not to disagree with you, but to emphasise this - a lot of stuff in v6 is intentionally easy to implement in hardware. Stuff like the 64/64 address split, fixed-length headers. The only benefit to fixing head length / next header at 40 bytes is to enable zero-knowledge hardware accel.

Essentially similar to people describing one of the benefits to pipelining on the M1 being fixed instruction length - you can pipeline a packet/instruction without parsing it.

IPv6 is no more difficult to understand than IPv4. In many ways it is easier since there are fewer legacy RFCs pertaining to it. System administrators don't understand it because they have not been forced to learn about it yet the same way they were forced to learn about IPv4.

Backwards compatibility would have made it far more complex.

If you sit down to look at IPv6 it's really quite straightforward. I think a lot of network admins are secretly hoping to retire before they have to learn a new technology though.

I'm just a programmer with a tiny homelab, and it took me less than a week to understand enough to be able to set up an IPv6 LAN. This included learning enough to be diagnosing and fixing routing/DHCP/RA issues in my router OS and all the LAN machines, implementing prefix-delegation to one of the LAN machines to make it a subrouter for Docker containers, and setting up NAT64 and DNS64 on the router so that the LAN machines could even disable IPv4 entirely. And those latter two were just me flexing because it was a homelab; a regular LAN wouldn't go that far.

I'm not sure what this "ton of system administrators that don't understand it" is having difficulty with.

Maybe it was easy because it was your home lab. System administrators will have to deal with orders of magnitude more complexity and thousands of devices. Even if their home labs are meticulously IPv6, moving a corporation to IPv6 is a major undertaking. How can they justify the effort if IPv4 still works and costs nothing?

>>>and a ton of system administrators that doesn't understand it (and for a reason, it's too complicated for nothing).

My comment was a response specifically to this.

> How can they justify the effort if IPv4 still works and costs nothing?

I believe the problem is that IPv4 is no longer costing nothing. It's gradually getting more sparse, and thus more expensive.

Soon only the major data-centers (AWS, Azure, GCP) will be able to afford IPv4 addresses, and you as an IPv4 only company will be forced to use their platform if you want to continue running IPv4 only.

> I'm not sure what this "ton of system administrators that don't understand it" is having difficulty with.

"It's different" is the primary thing I hear. I'm a network guy and I learned rudimentary v6 in college ten years ago. I'll be the first to admit I don't know as much as I should, but give me a day and a good resource and I can easily be back up to speed.

My boss on the other hand....."man, it's just so complicated, I hope we never change".

Sure, Setting it at home, or in lab is easy.

Now do it across complex collapsed core network with 1000's of devices spanning multiple locations with multiple WAN's of differing types that all have to route together

>it took me less than a week to understand enough to be able to set up an IPv6 LAN.

Don't mean to brag but it took the 12 year old me less than an afternoon (armed with a CISCO book) to understand IPv4 syntax/routing/ARP/DHCP + whatever and roll it out to my 2 computers lan.

The difficulty curve jump from IPv4 to IPv6 is humongous (IPv6 + ancillaries took me 2 days to setup in my home, and that's with a decade of IT experience.)

The issue is there are just so many officially right ways to do the same thing. Even assigning 'static' addresses has 3 official methods. Yes I get why there are so many of them (flexibility!) but it's a lot of stuff to learn and put together.

Did you misread the 6s in my comment as 4s? I'm not sure why you're telling me that IPv6 is more complex than IPv4 when my comment said nothing to the contrary.

> Don't mean to brag but it took the 12 year old me less than an afternoon (armed with a CISCO book) to understand IPv4 syntax/routing/ARP/DHCP + whatever and roll it out to my 2 computers lan.

Nothing about that is different for IPv6 for your 2 computer lab.

But did you understand how your LAN differs from the internet, how NAT works, all about port-forwards, firewall traversal and why some apps could traverse firewalls (UDP) and some ones not (TCP)? Or did that come later?

IPv4 has tons of hidden complexities people conveniently forget exist when they lament how terribly inaccessible IPv6 "really" is.

Where do I get a home router that has just a firewall for IPv6, and NAT for IPv4?

Well, the only one I have ready access to has that.

It's the freebie Technicollr C1100T that you get with a CenturyLink DSL connection.

My current home router is a cheap Microtik which does exactly what you describe. I also previously had a low end Ubiquiti EdgeRouter with the same setup as I have now. I am pretty sure the free router my ISP supplies does that as well but I have not had the opportunity to test it out.

I'm using an Ubiquity Edgerouter Pro PoE with exactly this configuration. I'm not saying it's the best product for this purpose, but I have used it in this way for several years now.

My main complaint about the model I have is that you only have hardware switching on the first two ports, making the remaining ports somewhat useless as the CPU isn't fast enough to route more than a few hundred Mb/s.

The Zyxel router my ISP issued me does exactly this.

Any home router that supports IPv6 would include this.

My fairly recent D-Link DIR-882 supports IPv6, and isn't even able to bring the IPv6 that the ISP modem router provides onto the LAN in any way.

The only reasonable way I can see to do this, would be to have an IPv4v2 packet within an IPv4v1 packet. So the v4v1 packet is delivered to its endpoint then stripped and the v4v2 packet traverses onwards to its destination.

This doesn't solve the dual-stack issues, as either the endpoint needs both v4v1 and v4v2 stacks, or it needs to be offloaded at the router - essentially re-inventing NAT.

What v6 has done, is essentially say there's no way to do this without breaking things, so we might as well break everything at once. So a lot of things that were optional, hacky bolt-ons in v4 have been adopted properly, because if we're going to add a 2nd stack, we might as well make the effort worth it - because lets face it, we're not going to have another chance to make a 20+ year transition any time soon.

> IPv6 is a disaster. It's too difficult to understand or configure properly, and it's too different from IPv4. There is a ton of software that breaks with IPv6, and a ton of system administrators that doesn't understand it (and for a reason, it's too complicated for nothing).

Now consider other tech that's even more different and how we jumped on it over the last decade. Anything related to mesh / overlay networks is just as complicated in practice and we learned how to use it just fine. People are capable of learning and lots of public traffic already goes over IPv6. And if they cannot learn about IPv6 given all the time we had available... maybe they should be replaced with people who can learn? We managed to move from IPX to IPv4 in the past and that was a bigger change.

> I would have preferred an IPv4 version 2, and extension to the address space of IPv4, possibly in a backward compatible way, so that applications, routers and equipment not built for the new protocol can continue to work, of course considering only a part of the address (e.g. if the network passes trough some old routers, it's not a problem since they only have to look at the most significant part of the address that is in the same place of the IPv4 address) and can ignore the extension.

This gets suggested all the time, but it's a fundamentally broken idea that could never work. What happens when one router uses the "extension" and the next one doesn't? You get a routing loop, so your packets get dropped. This would happen approximately 100% of the time when using this kind of "extension".

> And if you have to choose between two, you will choose the easier one, or the one you know, that is IPv4. A simple extension would have been far more easier to rollout.

Lol no it wouldn't. If you think people are dragging their feet on IPv6, that's nothing to how long it takes them to roll out an "extension" that's even less visible.

I’m having a hard time thinking of what kind of network topology would result in a routing loop. Can you elaborate?

It seems like the first router would have to be forwarding only a subset of a /32 to the second router; if the second router was responsible for the whole /32 (or more), then it would have no reason to send packets back to the first router even if it didn’t know about the extension. But forwarding a subset of a /32 to a router that doesn’t know about the extension is clearly a misconfiguration.

Two different /48s might be on two different sides of the world; the first router has no idea what the full path from it to either of them is (and of course the path shifts dynamically because that's how internet routing works) so it has no idea which paths might have IPv4-only routers on.

If you have to advocate addresses in IPv4-routable blocks (/32s, or I think /30s in practice because of needing a broadcast address etc.) then your protocol doesn't fix the address exhaustion problem and you still have to make a clear distinction between the parts of your network that are running "v4.1" and the parts that are running "v4". You'd end up with something like 6to4/6rd but running that way forever, with no prospect of ever improving, and the IPv4 address space fragmentation issues would get worse and worse. So there's not really any practical advantage over CGNAT.

>> I would have preferred an IPv4 version 2, and extension to the address space of IPv4, possibly in a backward compatible way

> This gets suggested all the time, but it's a fundamentally broken idea

Agreed. It needs to be 100% backwards compatible, or else it's going to break havoc on the internet.

And there's no such extension which can be made. Otherwise it would have been made by now.

So if you're going to break compatibility anyway, you might do so in a way which is clearly signaled and doesn't allow for the myriad of "undefined" failure modes that a theoretical IPv4.1 is going to have.

I'm not looking forward to asking my parents to visit http://[fe80::abcd:whatever] to access their router interface when something goes wrong. Hopefully they'll be able to use basic numeric IPs for the rest of their lives.

fe80::1 on link-local is/should almost always be configured as your gateway route. Works very well in corporate setups, too.

Interestingly Firefox does not seem to accept that as a valid address. It will force a a search for 'fe80::1' or even 'http://fe80::1'. Is it just me?

http://[fe80::1]

That doesn't work either. Does it work for you?

Depending on OS, you might need to actually put the interface name in there? As you can have fe80::1 on multiple interfaces...it being link-local. Maybe browsers are holding it back?

My ISP provided router responds to homerouter.cpe with both IPv6 and IPv4 address of its router webui.

IPv4 is a disaster, when you consider what you need to use it in a modern day system. IPv6 is far simpler in nature, and doesn't require many of hacks that have plagued enterprise networks like SD-WAN, NAT and NAT copium.

It's far easier to learn IPv6 from scratch than to learn IPv4, and then also learn the hacks underneath it, it's miserable.

> IPv6 is a disaster. It's too difficult to understand or configure properly

That's not really true. If you put a minimum of effort, you should be able to setup a local-only IPv6-subnet quite easily. And going from there to internet routable IPv6 takes almost no effort at all.

Yes. There are things which are different from IPv4. But it's not rocket-surgery. If you had any genuine interest in understanding it and put in some effort, you would find most of the "difficulties" are not really all that difficult.

If we were to start with a "from scratch" mindset, I would argue it's rather IPv4 which is hard to understand:

- subnetting? how? why?

- NAT?

- port-forwards?

- upnp assisted firewall traversal?

- upnp UN-assisted firewall traversal?

- Forcing app-developers to use UDP over TCP because... lack of end-to-end connectivity and ... again firewall traversal often only being possible with UDP.

- And what about carrier grade NATs?

And all other kinds of stuff we've just gotten used to being that way.

IPv6 solves most of those things right away... So the only thing you have to learn is the addressing-scheme... And that's about it.

I think everyone who complains about how IPv6 is "hard" has honestly just forgotten just how terrible hacky (and thus complex!) our IPv4 everyday situation really is.

I am not aware of the reason they went to such a high-complexity setup. They could have simply added a 4 or 6 digit hex code prefix to the IP addresses and figured a way to geographically lock that code.

Sure, that wouldn't give you the 340 trillion trillion trillion IPv6 addresses, but it would have turned 4,294,967,296 IPv4 addresses into 281,474,976,710,656 ipv? addresses and been easy enough to remember that on your local "block" you use idk, "AF09" as the prefix or whatever, and every person on the planet would have about 35 ip addresses (or ~9,000 with a 6 digit prefix) available to them on the new setup not even accounting for NAT

> I'd be willing to place a wager that there will be a $100mm company that is only IPv6 by 2030.

And at 60 percent usage, it will probably be India[1]

[1] https://www.google.com/intl/en/ipv6/statistics.html#tab=per-...

The trend on the "IPv6 Adoption" tab is fascinating. It looks like the inverse of the usual "high traffic during the week, low traffic during the weekend" pattern that I'm used to seeing in traffic graphs.

I wonder why? Is IPv6 adoption significantly higher for residential internet connections vs. corporate networks?

I mean yes, people who don't know what an IP is use whatever their ISP gives them, and ISPs have mostly rolled out v6 by now (albeit imperfectly). Businesses actually manage their networks actively, and they use what they know, which is almost always v4.

Mobile Network operators have been quite forerunning with regards to ipv6. That is primarily the driver for ipv6- iOS forcing apps to have an ipv6 backend was a huge driver too for services.

> iOS forcing apps to have an ipv6 backend

That‘s never been a requirement. What Apple does require is that apps correctly work over an IPv6-only network that uses NAT64/DNS64. Which means not hardcoding any IPv4 addresses and generally not expecting domains to exclusively return IPv4 addresses.

https://developer.apple.com/support/ipv6/

Corporate customers are very slow to transition to IPv6. Most of them aren't feeling pressure on the IPv4 space the way ISPs are and corporate security appliances are notoriously slow to adopt IPv6.

Yes, residential users have a lot more IPv6, a lot more of almost anything modern (but somewhat regardless of whether it's necessarily better).

Even if IPv6 is used internally, a lot of enterprise environments have outbound proxies which will use IPv4 by default. For example HP may have a /8, but all outbound is forced through a small number of PoPs with very enterprisey http proxies.

> Those customers will complain to their ISPs, which will provide incentive to get IPv6 deployed

Your experience with huge ISPs has obviously been different from mine. I am deeply grateful that I've benefited from two "first world" advantages: Comcast has (surprisingly) been very proactive about IPv6 support, and here in the Bay Area I have actual competition available for me to switch to. But in other parts of the country, that's for sure not true

---

to address the dig portion of your comment, the AAAA record (err, or lack of it) for github.com likely is a lot more impactful than HN

It's not that I think major users are going to switch, but I'll point out that GitLab actually does have AAAA records

fun fact: comcast have been proactive about ipv6 because their management network grew so large and unwieldy, through various acquisitions and long term inefficient use of space, that ipv4 RFC1918 10/8 (and 192.168 etc) was no longer sufficient to address all of their individual netblocks.

turns out that if you allocate a private /24 to every POP you can absolutely exhaust 10/8 in a big last mile ISP.

they started with ipv6 for their own management network before any public netblocks started getting rolled out to customers.

The issue is that each set top box, cable modem and everything else gets a management IP address on the network as well for allowing configuration changes/validating status/all that fun stuff.

The large push for IPv6 was started so that management of set top boxes/cable modems no longer required large islands of RFC1918 space where they had to deploy multiple NAT's to get traffic in/out of those environments.

yes, from what I've heard, they specified full ipv6 as a non-negotiable "must have" with their CPE vendors (and CMTS) almost 16, 18 years ago. Comcast gets a lot of shit for its poor customer service practices, as does any huge cable company, but the people who run the core IP network knew, and still do know what they're doing.

Here’s a deck that describes some of this (2006!): https://archive.nanog.org/meetings/nanog37/presentations/ala...

I never thought about the scale of their internal network. It’s nuts.

Does that mean they will need to deploy IPv8 with 256 bits of address space?

Or will IPv8 go straight to 1024 bits?

;)

Well, even when ISPs are dilligent in deploying IPv6, they still have to deal with troublesome end-user hardware that can't just be replaced overnight.

For example, here in Portugal the largest ISP (MEO) has had a wide deployment of IPv6 for many years. However, it's (up to very recently) main end-user router supplier (Thomson/Technicolor) has also had chronic IPv6 bugs in its firmware(1). MEO enables IPv6 by default nevertheless, but if you're an advanced user you'll have a hard time overlooking the random connection failures to IPv6 destinations.

(1) Specifically, it resets the flow label field randomly when it is non-zero (the case with most recent versions of Linux, macOS and, I guess, Windows). Turns out the flow label is taken into consideration by many load balancers so, if it changes mid-connection, your packets may end up in a server that has no knowledge of you and you get a connection reset.

I wonder when (or if) we will see new IPv6 only ISPs. That would be an indication that the transition is actually happening. Even though you note that most of your internet communications are done over IPv6, I doubt that you would be willing to go for IPv6 only ISP.

Lack of IPv4 addresses is a problem for new ISPs trying to enter the market, as even with levels of NAT, you need some minimal address space to serve your customers, which is harder and more expensive to get. So on one hand starting with IPv6 only stack would avoid these problems, but on the other hand it also means that every potential customer will be unhappy and in the end, you won't get many customers willing to pay you for IPv6 only connection.

> I wonder when (or if) we will see new IPv6 only ISPs.

If you have a mobile device on US T-Mobile you only get a IPv6 address on it:

* https://www.youtube.com/watch?v=nNMNglk_CvE

* https://pc.nanog.org/static/published/meetings/NANOG73/1645/...

* https://www.internetsociety.org/resources/deploy360/2014/cas...

Any access to IPv4 is through a proxy.

As long as your ISP supports 6 to 4 tunneling it is really no problem.

This is very good example how an ISP can move to IPv6, but my comment was mostly speculating about the IPv4 part. Even US T-Mobile needs to have a bunch of IPv4 addresses to maintain it's IPv4 proxy (and the size of IPv4 address space they need is determined by the size of their expected customer base).

So I was wondering when/if company in a similar situation would not feel the need to maintain IPv4 proxy or would seriously evaluate whether they still need it wrt of cost of the IPv4 address space necessary and potential loss caused by customers who would not be ok with missing IPv4 internet.

But maybe such speculation is missing the point, and cost of the IPv4 addresses is not as bad as keeping dual IPv4/IPv6 stack running in a datacenter. I don't know.

That said, you definitely have a point that right now, I should rather wonder how many other ISPs are moving to IPv6 only stack with IPv4 proxy like US T-Mobile did. Here I would definitely expect that telcos today are moving in this direction when planning new infrastructure (eg. for edge).

I think that once customers are only assigned IPv6 addresses, then IPv4 is a bit of a sunk cost with regards to addresses. You may be left with the 'overhead' of running the proxies for the IPv4 Internet.

Look at how long it took ISPs to turn off Usenet. I'm sure they'll keep running DS-Lite for decades to come, but they'll gradually allocate less and less resources to it, maybe put clauses in peering agreements that they pay less to upstreams who are IPv4-only. And then eventually IPv4 will become an optional extra, and then outsourced to one of a handful of firms still handling it...

I think a lot of SMBs are the holdouts for IPv6; their entire IT infrastructure is IPv4, and switching will be expensive because every router, subnet, VLAN, &c. must be upgraded. Small home networks are comparatively easy once all clients support IPv6: switch from a single subnet in the private range to a single /64 and add a stateful firewall. Since SMBs can run a lot of clients with very few (or even one!) public IP, IPv4 addresses will need to become much more expensive (or critical remote services will need to switch to IPv6 only) before it's cheaper to upgrade internal infrastructure to IPv6.

Note that NAT64/464XLAT solve the reverse problem. NAT-PT was the theoretical solution, but see RFC 4966 for all the reasons why that was a failure.

Many SMBs should probably go full cloud and once that's done they can "downgrade" the office network to zero-trust and maybe deploy IPv6 at the same time.

Color me skeptical.

It’s true that many SMB network infrastructure devices have poor support for IPv6, particularly w.r.t. the management interface.

But IPv6 support is old at this point. Very few things have no (as opposed to inconvenient) IPv6 support.

For heavens sake, there are versions of IRIX and VMS/VAX with IPv6 support. Those OSes run exclusively on hardware that hasn’t been manufactured for two decades, and the companies that released them have been defunct for almost as long. Windows XP (deprecated over 10 years ago) supports it. MacOS 10.7 (released 10 years ago) supports it.

In other words, if you’re willing to run network management from a dual-stack host, you can probably switch over all “regular hosts” today at zero hardware cost.

You have to be running seriously old hardware and software to not have IPv6 support today. So old that it should be on an air-gapped network anyway.

The only relatively common exception is Cisco Meraki and some cheap consumer-level AIO router/APs.

I'm not saying there are devices that don't support IPv6 (though there are), I'm saying the IT costs of reconfiguring the infra for IPv6 are higher than the costs of paying many times the current going rate for an IPv4 address.

The big hold up, IMO, is ISPs. They seem completely unmotivated to upgrade their infrastructure to support IPv6. Until a majority of them do that, I don't think any 100mm company will do a "IPv6 only" thing.

The cost of IPv4 addresses is slowly creeping upward, but hasn't hit a point of being prohibitive for a company. Once they hit near the $1k level, that's when I think things will start to change.

Maybe someday Verzion FiOS will support native v6. When I set up a Hurricane Electric tunnel over a decade ago I never thought I would still be using it in the 2020s.

Verizon is shameful. I guess you've seen this 43 page thread...

https://www.dslreports.com/forum/r32136440-Networking-IPv6-w...

I check it every couple of months but still no IPv6 for me. And I'm supposedly near people who have managed to get it to work.

The only way they will ever deploy IPv6 on FIOS is if someone forces them, e.g. a major content provider like Netflix goes IPv6 only.

I wonder if it would be commercially viable for Amazon to offer discounts to customers who connect over IPV6.

Amazon spends a lot of money on IPV4 blocks for AWS. They would directly benefit from wider IPV 6adoption.

This would be a great way to get regular people to care about this technology. That, in turn, would make ISPS care much more than they currently do.

They still assign a public IPv4 address to every EC2 instance by default and their IPv6 support is still a work-in-progress. So that's unlikely.

How will large corporate networks transition? I've recently seen a large organization using the 5.0.0.0/8 address space. The decision to use these addresses was made a long time ago and they still didn't switch to an actual private address space and choose to deal with all the issues instead.

Dual Stack. Start off with by deploying IPv6 across the network without touching the IPv4 environment. Most modern operating systems will just automatically detect they have an IPv6 router and auto-configure. Big advantage of IPv6 is that address autoconfiguration is built into the protocol itself - no need for DHCP, Static Configuration, etc...

just use 64:ff9b::/96 first if you own a subnet? if not just buy a good firewall that supports v6 (sadly cisco meraki does not work well, tough)

They mostly won't.

Part of the problem is older consumer networking equipment. Comcast has supported IPv6 for quite a while, but many routers I've used are not configured correctly out of the box to work with Comcast's IPv6 implementation. Even getting IPv6 to work with my new UniFi equipment took changing a setting or two away from the defaults, though that is more expected with prosumer and enterprise gear.

I bet there are lots of customers with 10 year old gigabit routers that have had no reason to be replaced, and will still be perfectly serviceable for another 10 years, especially if they use a separate wireless access point. Many of these people probably don't even know what any of this means.

I setup an IPv6-only server a few years back. At the time the biggest annoyance was that github wasn't available - so I couldn't clone my dotfiles, projects, and things.

Having checked just now I see that github is still IPv4-only.

>deal with the fall-out of some nn% of their customer not being compatible

Most of their customers in pretty much everywhere. Global IPv6 adaptation is at like 33% and only a couple of countries pass the 50% mark.

Virgin here in the UK, with 20% of broadband residential market share, one of the top 3, don't seem to give a fuck. Still ipv4 only.

The obligatory link for that is:

https://havevirginmediaenabledipv6yet.co.uk/

> Answer: No [crying face emoji]

> We've been asking since March 2010.

I was on Chorus/UPC in Ireland. I asked them in 2013 when v6 was coming, they told me it was coming in 2014. I asked them in 2014 when it was coming, and they said 2014. I asked them in 2015 when it was coming, and they said 2014.

Then Virgin bought them.

It is not just ISP, I would guess a TON of corporate, enterprise, and business networks have no functionality of ipv6, even if their hardware supports it, the first thing the network admin does is disable all that....

I am surprised you say you work has functional IPv6, I know we have not even talked about enabling traffic anywhere for IPv6

You can run a whole company on one IPv4 address (or zero if you use a CDN) so there's no reason to go IPv6-only.

>deployed for the next 100 years

bold for you to assume we will have active internet for 100 more years /s...

IPv4 is perfectly sufficient for your bunker community's LAN.

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