IPv6 in 2020 — Nope, still dreamland

It’s that time of the year: lots of my friends and acquaintances went to FOSDEM, which is great, and at least one complained about something not working over IPv6, which prompted me to share once again my rant over the newcomer-unfriendly default network of a a conference that is otherwise very friendly to new people. Which then prompted the knee-jerk reaction of people who expect systems to work in isolation, calling me a hater and insulting me. Not everybody, mind you — on Twitter I did have a valid and polite conversation with two people, and while it’s clear we disagree on this point, insults were not thrown. Less polite people got blocked because I have no time to argue with those who can’t see anyone else’s viewpoint.

So, why am I insisting that IPv6 is still not ready in 2020? Well, let’s see. A couple of years ago, I pointed out how nearly all of the websites that people would use, except for the big social networks, are missing IPv6. As far as I could tell, nothing has changed whatsoever for those websites in the intervening two years. Even the number of websites that are hosted by CDNs like Akamai (which does support IPv6!), or service providers like Heroku are not served over IPv6. So once again, if you’re a random home user, you don’t really care about IPv6, except maybe for Netflix.

Should the Internet providers be worried, what with IPv4 exhaustion getting worse and worse? I’d expect them to be, because as Thomas said on Twitter, the pain is only going to increase. But it clearly has not reached the point where any of the ISPs, except a few “niche” ones like Andrews & Arnold, provide their own website over IPv6 — the exception appears to be Free, who if I understood it correctly, is one of the biggest providers in France, and does publish AAAA records for their website. They are clearly in the minority right now.

Even mobile phone providers, who everyone and their dog appear to always use as the example of consumer IPv6-only networks, don’t seem to care — at least in Europe. It looks like AT&T and T-Mobile US do serve their websites over IPv6.

But the consumer side is not the only reason why I insist that in 2020, IPv6 is still fantasy. Hosting providers don’t seem to have understood IPv6 either. Let’s put aside for a moment that Automattic does not have an IPv6 network (not even outbound), and let’s look at one of the providers I’ve been using for the past few years: Scaleway. Scaleway (owned by Iliad, same group as Online.net) charges you extra for IPv4. It does, though, provide you with free IPv6. It does not, as far as I understand, provide you with multiple IPv6 per server, though, which is annoying but workable.

But here’s a quote from a maintenance email they sent a few weeks ago:

During this maintenance, your server will be powered off, then powered on on another physical server. This operation will cause a downtime of a few minutes to an hour, depending on the size of your local storage. The public IPv4 will not change at migration, but the private IPv4 and the IPv6 will be modified due to technical limitations.

Scaleway email, 2020-01-28. Emphasis theirs.

So not only the only stable address the servers could keep is the IPv4 (which, as I said, is a paid extra), but they cannot even tell you beforehand which IPv6 address your server will get. Indeed, I decided at that point that the right thing to do was to just stop publishing AAAA records for my websites, as clearly I can’t rely on Scaleway to persist them over time. A shame, I would say, but that’s my problem: nobody is taking IPv6 seriously right now but a few network geeks.

But network geeks also appear to like UniFi. And honestly I do, too. It worked fairly well for me, most of the time (except for the woes of updating Mongodb), and it does mostly support IPv6. I have a full IPv6 setup at home with UniFi and Hyperoptic. But at the same time, the dashboard is only focused on IPv4, everywhere. A few weeks ago it looked like my IPv6 network had a sad (I only noticed because I was trying to reach one of my local machines with its AAAA hostname), and I had no way to confirm it was the case: I eventually just rebooted the gateway, and then it worked fine (and since I have a public IPv4, Hyperoptic gives me a stable IPv6 prefix, so I didn’t have to worry about that), but even then I couldn’t figure out if the gateway got any IPv6 network connection from its UIs.

I’m told OpenWRT got better about this. You’re no longer required to reverse engineer the source to figure out how to configure a relay. But at the same time, I’m fairly sure they are again niche products. Virgin Media Ireland’s default router supported IPv6 — to a point. But I have yet to see any Italian ISP providing even the most basic of DS-Lite by default.

Again, I’m not hating on the protocol, or denying the need to move onto the new network in short term. But I am saying that network folks need to start looking outside of their bubble, and try to find the reasons for why nothing appears to be moving, year after year. You can’t blame it on the users not caring: they don’t want to geek out on which version of the Internet Protocol they are using, they want to have a working connection. And you can’t really expect them to understand the limits of CGNs — 64k connections might sound ludicrously few to a network person, but for your average user it sounds too much: they only are looking at one website at a time! (Try explaining to someone who has no idea how HTTP works that you get possibly thousands of connections per tab.)

Fantasyland: in the world of IPv6 only networks

It seems to be the time of the year when geeks think that IPv6 is perfect, ready to be used, and the best thing after sliced bread (or canned energy drinks). Over on Twitter, someone pointed out to me that FontAwesome (which is used by the Hugo theme I’m using) is not accessible over an IPv6-only network, and as such the design of the site is broken. I’ll leave aside my comments on FontAwesome because they are not relevant to the rant at hand.

You may remember I called IPv6-only networks unrealistic two years ago, and I called IPv6 itself a geeks’ wet dream last year. You should then not be surprised to find me calling this Fantasyland an year later.

First of all, I want to make perfectly clear that I’m not advocating that IPv6 deployment should stop or slow down. I really wish it would be actually faster, for purely selfish reasons I’ll get to later. Unfortunately I had to take a setback when I moved to London, as Hyperoptic does not have IPv6 deployment, at least in my building, yet. But they provide a great service, for a reasonable price, so I have no intention to switch to something like A&A just to get a good IPv6 right now.

$ host hyperoptic.com
hyperoptic.com has address 52.210.255.19
hyperoptic.com has address 52.213.148.25
hyperoptic.com mail is handled by 0 hyperoptic-com.mail.eo.outlook.com.

$ host www.hyperoptic.com
www.hyperoptic.com has address 52.210.255.19
www.hyperoptic.com has address 52.213.148.25

$ host www.virginmedia.com
www.virginmedia.com has address 213.105.9.24

$ host www.bt.co.uk
www.bt.co.uk is an alias for www.bt.com.
www.bt.com has address 193.113.9.162
Host www.bt.com not found: 2(SERVFAIL)

$ host www.sky.com
www.sky.com is an alias for www.sky.com.edgekey.net.
www.sky.com.edgekey.net is an alias for e1264.g.akamaiedge.net.
e1264.g.akamaiedge.net has address 23.214.120.203

$ host www.aaisp.net.uk
www.aaisp.net.uk is an alias for www.aa.net.uk.
www.aa.net.uk has address 81.187.30.68
www.aa.net.uk has address 81.187.30.65
www.aa.net.uk has IPv6 address 2001:8b0:0:30::65
www.aa.net.uk has IPv6 address 2001:8b0:0:30::68

I’ll get back to this later.

IPv6 is great for complex backend systems: each host gets their own uniquely-addressable IP, so you don’t have to bother with jumphosts, proxycommands, and so on so forth. Depending on the complexity of your backend, you can containerize single applications and then have a single address per application. It’s a gorgeous thing. But as you move towards user facing frontends, things get less interesting. You cannot get rid of IPv4 on the serving side of any service, because most of your visitors are likely reaching you over IPv4, and that’s unlikely to change for quite a while longer still.

Of course the IPv4 address exhaustion is a real problem and it’s hitting ISPs all over the world right now. Mobile providers already started deploying networks that only provide users with IPv6 addresses, and then use NAT64 to allow them to connect to the rest of the world. This is not particularly different from using an old-school IPv4 carrier-grade NAT (CGN), which a requirement of DS-Lite, but I’m told it can get better performance and cost less to maintain. It also has the advantage of reducing the number of different network stacks that need to be involved.

And in general, having to deal with CGN and NAT64 add extra work, latency, and in general bad performance to a network, which is why gamers, as an example, tend to prefer having a single-stack network, one way or the other.

$ host store.steampowered.com
store.steampowered.com has address 23.214.51.115

$ host www.gog.com
www.gog.com is an alias for gog.com.edgekey.net.
gog.com.edgekey.net is an alias for e11072.g.akamaiedge.net.
e11072.g.akamaiedge.net has address 2.19.61.131

$ host my.playstation.com
my.playstation.com is an alias for my.playstation.com.edgekey.net.
my.playstation.com.edgekey.net is an alias for e14413.g.akamaiedge.net.
e14413.g.akamaiedge.net has address 23.214.116.40

$ host www.xbox.com
www.xbox.com is an alias for www.xbox.com.akadns.net.
www.xbox.com.akadns.net is an alias for wildcard.xbox.com.edgekey.net.
wildcard.xbox.com.edgekey.net is an alias for e1822.dspb.akamaiedge.net.
e1822.dspb.akamaiedge.net has address 184.28.57.89
e1822.dspb.akamaiedge.net has IPv6 address 2a02:26f0:a1:29e::71e
e1822.dspb.akamaiedge.net has IPv6 address 2a02:26f0:a1:280::71e

$ host www.origin.com
www.origin.com is an alias for ea7.com.edgekey.net.
ea7.com.edgekey.net is an alias for e4894.e12.akamaiedge.net.
e4894.e12.akamaiedge.net has address 2.16.57.118

But multiple other options started spawning around trying to tackle the address exhaustion problem, faster than the deployment of IPv6 is happening. As I already noted above, backend systems, where the end-to-end is under control of a single entity, are perfect soil for IPv6: there’s no need to allocate real IP addresses to these, even when they have to talk over the proper Internet (with proper encryption and access control, goes without saying). So we won’t see more allocations like Xerox’s or Ford’s of whole /8 for backend systems.

$ host www.xerox.com
www.xerox.com is an alias for www.xerox.com.edgekey.net.
www.xerox.com.edgekey.net is an alias for e1142.b.akamaiedge.net.
e1142.b.akamaiedge.net has address 23.214.97.123

$ host www.ford.com
www.ford.com is an alias for www.ford.com.edgekey.net.
www.ford.com.edgekey.net is an alias for e4213.x.akamaiedge.net.
e4213.x.akamaiedge.net has address 104.123.94.235

$ host www.xkcd.com
www.xkcd.com is an alias for xkcd.com.
xkcd.com has address 151.101.0.67
xkcd.com has address 151.101.64.67
xkcd.com has address 151.101.128.67
xkcd.com has address 151.101.192.67
xkcd.com has IPv6 address 2a04:4e42::67
xkcd.com has IPv6 address 2a04:4e42:200::67
xkcd.com has IPv6 address 2a04:4e42:400::67
xkcd.com has IPv6 address 2a04:4e42:600::67
xkcd.com mail is handled by 10 ASPMX.L.GOOGLE.com.
xkcd.com mail is handled by 20 ALT2.ASPMX.L.GOOGLE.com.
xkcd.com mail is handled by 30 ASPMX3.GOOGLEMAIL.com.
xkcd.com mail is handled by 30 ASPMX5.GOOGLEMAIL.com.
xkcd.com mail is handled by 30 ASPMX4.GOOGLEMAIL.com.
xkcd.com mail is handled by 30 ASPMX2.GOOGLEMAIL.com.
xkcd.com mail is handled by 20 ALT1.ASPMX.L.GOOGLE.com.

Another technique that slowed down the exhaustion is SNI. This TLS feature allows to share the same socket for applications having multiple certificates. Similarly to HTTP virtual hosts, that are now what just about everyone uses, SNI allows the same HTTP server instance to deliver secure connections for multiple websites that do not share their certificate. This may sound totally unrelated to IPv6, but before SNI became widely usable (it’s still not supported by very old Android devices, and Windows XP, but both of those are vastly considered irrelevant in 2018), if you needed to provide different certificates, you needed different sockets, and thus different IP addresses. It would not be uncommon for a company to lease a /28 and point it all at the same frontend system just to deliver per-host certificates — one of my old customers did exactly that, until XP became too old to support, after which they declared it so, and migrated all their webapps behind a single IP address with SNI.

Does this mean we should stop caring about the exhaustion? Of course not! But if you are a small(ish) company and you need to focus your efforts to modernize infrastructure, I would not expect you to focus on IPv6 deployment on the frontends. I would rather hope that you’d prioritize TLS (HTTPS) implementation instead, since I would rather not have malware (including but not limited to “coin” miners), to be executed on my computer while I read the news! And that is not simple either.

$ host www.bbc.co.uk
www.bbc.co.uk is an alias for www.bbc.net.uk.
www.bbc.net.uk has address 212.58.246.94
www.bbc.net.uk has address 212.58.244.70

$ host www.theguardian.com  
www.theguardian.com is an alias for guardian.map.fastly.net.
guardian.map.fastly.net has address 151.101.1.111
guardian.map.fastly.net has address 151.101.65.111
guardian.map.fastly.net has address 151.101.129.111
guardian.map.fastly.net has address 151.101.193.111

$ host www.independent.ie
www.independent.ie has address 54.230.14.45
www.independent.ie has address 54.230.14.191
www.independent.ie has address 54.230.14.196
www.independent.ie has address 54.230.14.112
www.independent.ie has address 54.230.14.173
www.independent.ie has address 54.230.14.224
www.independent.ie has address 54.230.14.242
www.independent.ie has address 54.230.14.38

Okay I know these snippets are getting old and probably beating a dead horse. But what I’m trying to bring home here is that there is very little to gain in supporting IPv6 on frontends today, unless you are an enthusiast or a technology company yourself. I work for a company that believes in it and provides tools, data, and its own services over IPv6. But it’s one company. And as a full disclosure, I have no involvement in this particular field whatsoever.

In all of the examples above, which are of course not complete and not statistically meaningful, you can see that there are a few interesting exceptions. In the gaming world, XBox appears to have IPv6 frontends enabled, which is not surprising when you remember that Microsoft even developed one of the first tunnelling protocols to kickstart adoption of IPv6. And of course XKCD, being ran by a technologist and technology enthusiast couldn’t possibly ignore IPv6, but that’s not what the average user needs from their Internet connection.

Of course, your average user spends a lot of time on platforms created and maintained by technology companies, and Facebook is another big player of the IPv6 landscape, so they have been available over it for a long while — though that’s not the case of Twitter. But at the same time, they need their connection to access their bank…

$ host www.chase.com
www.chase.com is an alias for wwwbcchase.gslb.bankone.com.
wwwbcchase.gslb.bankone.com has address 159.53.42.11

$ host www.ulsterbankanytimebanking.ie
www.ulsterbankanytimebanking.ie has address 155.136.22.57

$ host www.barclays.co.uk
www.barclays.co.uk has address 157.83.96.72

$ host www.tescobank.com
www.tescobank.com has address 107.162.133.159

$ host www.metrobank.co.uk
www.metrobank.co.uk has address 94.136.40.82

$ host www.finecobank.com
www.finecobank.com has address 193.193.183.189

$ host www.unicredit.it
www.unicredit.it is an alias for www.unicredit.it-new.gtm.unicreditgroup.eu.
www.unicredit.it-new.gtm.unicreditgroup.eu has address 213.134.65.14

$ host www.aib.ie
www.aib.ie has address 194.69.198.194

to pay their bills…

$ host www.mybills.ie
www.mybills.ie has address 194.125.152.178

$ host www.airtricity.ie
www.airtricity.ie has address 89.185.129.219

$ host www.bordgaisenergy.ie
www.bordgaisenergy.ie has address 212.78.236.235

$ host www.thameswater.co.uk
www.thameswater.co.uk is an alias for aerotwprd.trafficmanager.net.
aerotwprd.trafficmanager.net is an alias for twsecondary.westeurope.cloudapp.azure.com.
twsecondary.westeurope.cloudapp.azure.com has address 52.174.108.182

$ host www.edfenergy.com
www.edfenergy.com has address 162.13.111.217

$ host www.veritasenergia.it
www.veritasenergia.it is an alias for veritasenergia.it.
veritasenergia.it has address 80.86.159.101
veritasenergia.it mail is handled by 10 mail.ascopiave.it.
veritasenergia.it mail is handled by 30 mail3.ascotlc.it.

$ host www.enel.it
www.enel.it is an alias for bdzkx.x.incapdns.net.
bdzkx.x.incapdns.net has address 149.126.74.63

to do shopping…

$ host www.paypal.com
www.paypal.com is an alias for geo.paypal.com.akadns.net.
geo.paypal.com.akadns.net is an alias for hotspot-www.paypal.com.akadns.net.
hotspot-www.paypal.com.akadns.net is an alias for wlb.paypal.com.akadns.net.
wlb.paypal.com.akadns.net is an alias for www.paypal.com.edgekey.net.
www.paypal.com.edgekey.net is an alias for e3694.a.akamaiedge.net.
e3694.a.akamaiedge.net has address 2.19.62.129

$ host www.amazon.com
www.amazon.com is an alias for www.cdn.amazon.com.
www.cdn.amazon.com is an alias for d3ag4hukkh62yn.cloudfront.net.
d3ag4hukkh62yn.cloudfront.net has address 54.230.93.25

$ host www.ebay.com 
www.ebay.com is an alias for slot9428.ebay.com.edgekey.net.
slot9428.ebay.com.edgekey.net is an alias for e9428.b.akamaiedge.net.
e9428.b.akamaiedge.net has address 23.195.141.13

$ host www.marksandspencer.com
www.marksandspencer.com is an alias for prod.mands.com.edgekey.net.
prod.mands.com.edgekey.net is an alias for e2341.x.akamaiedge.net.
e2341.x.akamaiedge.net has address 23.43.77.99

$ host www.tesco.com
www.tesco.com is an alias for www.tesco.com.edgekey.net.
www.tesco.com.edgekey.net is an alias for e2008.x.akamaiedge.net.
e2008.x.akamaiedge.net has address 104.123.91.150

to organize fun with friends…

$ host www.opentable.com
www.opentable.com is an alias for ev-www.opentable.com.edgekey.net.
ev-www.opentable.com.edgekey.net is an alias for e9171.x.akamaiedge.net.
e9171.x.akamaiedge.net has address 84.53.157.26

$ host www.just-eat.co.uk
www.just-eat.co.uk is an alias for 72urm.x.incapdns.net.
72urm.x.incapdns.net has address 149.126.74.216

$ host www.airbnb.com
www.airbnb.com is an alias for cdx.muscache.com.
cdx.muscache.com is an alias for 2-01-57ab-0001.cdx.cedexis.net.
2-01-57ab-0001.cdx.cedexis.net is an alias for evsan.airbnb.com.edgekey.net.
evsan.airbnb.com.edgekey.net is an alias for e864.b.akamaiedge.net.
e864.b.akamaiedge.net has address 173.222.129.25

$ host www.odeon.co.uk
www.odeon.co.uk has address 194.77.82.23

and so on so forth.

This means that for an average user, an IPv6-only network is not feasible at all, and I think the idea that it’s a concept to validate is dangerous.

What it does not mean, is that we should just ignore IPv6 altogether. Instead we should make sure to prioritize it accordingly. We’re in a 2018 in which IoT devices are vastly insecure, so the idea of having a publicly-addressable IP for each of the devices in your home is not just uninteresting, but actively frightening to me. And for the companies that need the adoption, I would hope that the priority right now would be proper security, instead of adding an extra layer that would create more unknowns in their stack (because, and again it’s worth noting, as I had a discussion about this too, it’s not just the network that needs to support IPv6, it’s the full application!). And if that means that non-performance-critical backends are not going to be available over IPv6 this century, so be it.

One remark that I’m sure is going to arrive from at least a part of the readers of this, is that a significant part of the examples I’m giving here appear to all be hosted on Akamai’s content delivery network which, as we can tell from XBox’s website, supports IPv6 frontends. “It’s just a button to press, and you get IPv6, it’s not difficult, they are slackers!” is the follow up I expect. For anyone who has worked in the field long enough, this would be a facepalm.

The fact that your frontend can receive IPv6 connections does not mean that your backends can cope with it. Whether it is for session validation, for fraud detection, or just market analysis, lots of systems need to be able to tell what IP address a connection was coming from. If your backend can’t cope with IPv6 addresses being used, your experience may vary between being unable to buy services and receiving useless security alerts. It’s a full stack world.