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I hope IPv6 never catches on (apenwarr.ca)
92 points by rcfox on March 28, 2011 | hide | past | favorite | 74 comments

> In short, any IPv6 transition plan involves everyone having an IPv4 address, right up until everyone has an IPv6 address, at which point we can start dropping IPv4, which means IPv6 will start being useful.

Sigh, no. Not correct -- in the last 8 or 9 years, engineers have been cooking up various ways to bridge the gap. The transition landscape looks a lot different today than it does in 2003. Comcast (the largest MSO in the US) has detailed their transition plans here (tl;dr, it's v6-only customer addressing, with v4 reachability via DS-lite and CGN): http://www.comcast6.net/

Summary here: http://en.wikipedia.org/wiki/IPv6_transition_mechanisms

No no no no no no no no.

NAT is not a solution. Internet is cool because it allows peer-to-peer communication. It's also cool because everyone can host servers and everyone else can connect to them. This allows exploration and experimentation.

Please don't force some people to become second-class citizens behind a NAT just because some artificial resource is running out. It's bad enough in the real world.

Also, "the addresses are just to long" is a nonsense argument, for many reasons. And HTTP is only one of the many protocols. But I think I've fed the troll enough.

> But I think I've fed the troll enough.

I'm glad someone said it. This apenwarr seems to have some good karma here on HN, but IMO a lot of what he says is heavily misinformed and biased.

I had the urge to go point-by-point of his post and refute each with proper references and practical examples, but I then I realized that he is just a troll and that would be feeding him.

Some of his points, like about IPv6 addresses being too long and hard to memorize and that NAT is good/enough for users, basically points that he probably doesn't have much experience with network management and how IP works (specially IPv6 networks). This is strange coming from someone who was the original author of wvdial.

I have already argued here on HN why IPv6 addresses are easier to memorize: http://news.ycombinator.com/item?id=1804038

So, Avery is just this guy, you know? It's not his fault if some of you want to fanboy on his every blog post.

I think he's right more often than he's wrong. (Although not in this article, which is nearly all wrong when it's not rehashing points that have been argued both ways for many years w/o a resolution.. hang out on NANOG for even a month and you'll see what I mean.) And I appreciate that he feels he has to get his half-baked thoughts posted now, before being swallowed by the Borg. Which will certainly change his opinion of some of this stuff if he ends up working with the ipv6 people @ Google.

The addresses aren't particularly human-memorable though. But yes, I agree on everything else. Another source for the pain of NAT is that it screws you if the server is limiting per-IP transactions. There's a supercheap ISP where I am that has a (cough) transparent proxy that isn't quite transparent - people on this ISP bitch constantly at being told by site X that "your IP address has reached it's allocation" when they've never visited that site before.

And what about whitehat countermeasures? Finding the source IP address is so much more useful than "it came from this giant ISP... somewhere". ISP-level NATting has nothing but disaster stamped all over it.

>The addresses aren't particularly human-memorable though.

IP addresses are? What is Facebook's IP? Googles? I have no idea because.... why on earth would I care?

I don't care about those two either. But when administrating my office computers internally and externally, I find it helpful. Likewise when I'm working on a device that is underpowered to the point where it has to use IP addresses because it can't handle DNS, I need IP addresses. When I want to use my friend's servers for network testing, I prefer to use IP addresses rather than names.

Names introduce an extra layer of complexity that makes troubleshooting more difficult at times. The world exists beyond facebook and google. You may not care about that, but I do.

I worked in Network Engineering for years. You will absorb the new unmemorable IP6 addresses the same way you absorbed the unmemorable IP4 ones.

Plus you potentially have the added benefit of having the MAC right there in the IP so you don't have to do any extra effort to figure out what it is.

In my experience, it is helpful to be able to remember IP addresses instead of just urls. Not a dealbreaker, but useful in some cases. Example - I set up a VPS server as a testbed/development server/socks proxy, but didn't bother to register a domain with it. It would suck to look it up the long IPv6 address the whenever I connect to it on a new device, or try to show it to someone else. The ten digit IPv4 address is fairly easy to memorize in comparison.

So NAT, and the plethora of unholy "protocols" for traversing it, are acceptable solutions that will last us indefinitely, but DNS is so unusable that we're better off typing in IP addresses?

The real damage caused by NAT is mostly invisible. Because some people don't have IP addresses, creators of applications and protocols must assume that nobody does, making many ideas complicated or impossible. We won't know what branches of innovation we've missed out on until this constraint is lifted. As James Burke teaches us, it's these little things that so often change the course of technology.

I totally agree with this. We've been in a firewalled world of NAT pain for so long that developers have largely forgotten how to think outside the client/server box it has imposed on us.

I feel this acutely every time I try and spread the word about my project (PageKite, a system for putting "servers" on mobile and personal devices). People just look at me funny and go "why would I want that when I can rent a vserver somewhere in the cloud?"

Once upon a time people would have asked "why do I have to rent some external machine instead of using this one I already own and this Internet connection I already have?".

"PageKite, a system for putting "servers" on mobile and personal devices"

Cool idea! I'm checking it out now.

It wonders me that most IPv6 bashing comes "mainly" from US where the IPv6 adoption rate is low. If you check Asia or Europe there are providers running IPv6 in their backbone for a decade (e.g. space.net), also nearly every provider at least announces one IPv6 prefix (at least for testing).

Imho this shows, that people dissing IPv6 today have not had a look into it and are now in a hurry.

Amazon e.g. does not announce a single IPv6 prefix, imho a bad sign about their networking competence: They don't even have a testing infrastructure ready.



We also still use the English system of weights and measures. America thinks anything new in the area of standards is communism or something.

I think the big flaw is, there will be a whole bunch of people who can't get ipv4 addresses. like kids in dorms. That may not be your demographic, fine, but djb's argument works both ways. very soon there will surely be at least one customer with ipv6 only. poof overnight every server in the universe supports ipv6.

ipv6 has been coming forever. It seems like this year, friends actually have to come up with ipv6 deliverables. that's never happened before. hell, comcast is going to be testing ipv6 this year. that's a big indicator with flashing lights and sirens.

Where are these dorms that are only IPv4 ready anyway? My university was on the ball with IPv6 years ago... If anyone can mitigrate easily, it is schools.

MIne. don't know why, but I'm not able to connect outside using ipv6. I should ask network people, but they probably don't know.

Are you sure it is not a misconfigured windows on your network? It happened all the time at my university (one windows with 6to4 starts broadcasting router advertisements).

Mine is. We have IPv6 enabled (so it works within the intranet), but it isn't actually routed to the external internet. Last I checked the network admins were waiting for an IPv6-capable firewall to be installed before enabling the routes.

As he explains you don't need an ipv4 address for every person. Just give em a shared one and use NAT. Our entire office has just one public IP address and nobody knows the difference.

So when your entire neighborhood is NAT'd and you want to use XBox Live you'll, what, call up your ISP and ask nicely to have the right ports forwarded to you?

NAT works in an office environment because most offices aren't doing anything more than web and email. Home usage scenarios are significantly broader and harder to keep working behind carrier grade NAT.

You still need to do that with XBox? Does that mean you can't run more than one XBox at home from one IP address?

Presumably (I haven't got one) the XBoxes can use UPnP to negotiate external ports with the home router, which, unlike the ISP's router, can trust the devices on its network.

It's not people that need IP addresses, it is devices. And there are potentially many more than 1 device per person.

I have 6 IP-connected devices on my desk alone. This isn’t a potentiality.

For every techno geek like us, there are many more people with 0 devices that require an IP. OP was comparing number of IPs in IPv4 with number of people on earth. Since we are only just now starting to run out of IPv4 addresses (the last big blocks were assigned recently, but there are still gaps and sparsely filled blocks), it seems safe to say that on average the number of IP enabled devices is lower than the number of people. That won't last long though.

As technology filters down to the third world, and (assuming there isn't some massive device convergence that reduces demand for IPs in the first world) the ratio of devices to people will rapidly become skewed. It's a lot easier to pump out cell-phones than babies after all :D

Totally workable solution, but i have to point back at djb's argument.

If there is even a single customer that only has access to ipv6, you have to support them 4 and 6. My office, and your office will of course stay on ipv4. I'm pretty confident least one university will soon be strapped for cash, and sell of the boatload of their ipv4 space, and just give the dorms ipv6 addresses. there will be much whining and complaining, and everyone will support ipv6 the next week.

There is 6-to-4 translation available. So we need to move clients to 6 in order that servers can move to 6.

On the plus side, this (staying with IPv4 behind NAT behind NAT...) will further instil the idea that an IP address is not a person. As soon as governments/corporations loose the ability to track/sue individual people, they'll be all over IPv6.

Coporation should not be synonymous with government. It might be the case that these are the same in a particular country or era, but we're not doomed to such a fate. Fascism can be stopped, but to do it we need to advocate the idea that state and economics should be as separate as state and church.

> Corporation should not be synonymous with government.

They aren't the same thing, but that doesn't prevent them from having features in common. They are both big, powerful entities that don't have my interests at heart, and are both therefore threats to my liberty (especially when they work together to undermine it).

Sorry, I meant it as "or". I guess I should have used || instead of /

So, I'm pretty sure I've heard people involved in carrier-grade NAT, NAT444, etc discussing what they have to in order to comply with requirements that IP:port tuples be usable to track back to their customers..

Nice try at a silver lining tho. :)

NAT is an astonishingly horrific idea that should have never been implemented, and his arguement about "one valuable customer still on IPv4" reaks of the same nonsense that has held back web development for years with IE6.

Could you expand on that? What is it about NAT that is an astonishingly horrific idea?


All that to do something that should be as simple as open(some_ip)

Absolutely. Being behind NAT at home, it is a pain having to open up ports on the router in order to run anything that requires an inbound connection. At the same time, it is rather comforting to know that making an inbound connection is so hard.

What do you think of the suggestion made by the author of the article that, even if we had IPv6 everywhere, we'd still put a lot of networks behind NAT, for reasons of security.

"What do you think of the suggestion made by the author of the article that, even if we had IPv6 everywhere, we'd still put a lot of networks behind NAT, for reasons of security."

It's utter bullshit. Stateful firewalls will of course continue to exist; doing Network Address Translation in addition will be completely pointless.

Ignore IE 6 - they will get the hint eventually

The author of this piece gets several details completely wrong.

And NAT is not a solution. Period. End-to-end, ever hear of it?


While the author of this post is content to list reasons why IPv6 sucks, a better approach would be to realize there will be a billion dollar market created from the switch. I am going to predict that at least one and probably 2-5 companies in the next YC class are focused on this problem.

If the change is unnecessary, then that's a billion dollar broken window.

The way things are going, there isn't going to be a majority changeover until the window is already broken. Then it will be done rushed and expensive; remember Y2K? Everybody keep your networking skills up-to-date, there is likely to be a short, sharp opportunity to make good money - probably in a year to four (if they do wait for things to start actually breaking, it will be a little longer before they reach that point).

Oh downvoters, you are so predictable. For the sake of clarity: I do not believe the change to be unnecessary. However, if I am wrong, then to create make-work on that basis is an utter waste. Happy now?

The Web != The Internet

What about VNC/Remote desktop/SSH?

What about protocols that don't use port numbers like ICMP and basically everything that's not UDP or TCP?

What about sites that grab data from other sources, often needing IP whitelisting

Sharing IPs for SSL HTTP services is tricky, do dedicated hosting/VPS users actually want to give their certs to the ISP (private keys and all) so they can manage it?

...and many P2P UDP protocols don't use a well-known port anyway. Because even if they did, NAT would screw them by mapping it.

I agree with the article's rant about port number being obsolete. A service space of 16 bits sucks. IPV6 provides a Solution to this: advertise a different IPV6 address (multi-home) for each service, and use the DNS to resolve, not the TCP address. I think.

Actually my point was that with protocols like GRE it difficult to NAT more than one stream through an IP address. Also even if you do work that out (people have it seems) you need to work it out for every protocol which is not how the layers of TCP/IP were supposed to work.

Even worse, TCP requires ICMP for PMTU discovery.

> When I bring my laptop to my friend's house and join his WLAN, why can't he ping it by name? Because DNS sucks. Why doesn't it show up by name in his router control panel so he knows which box is using his bandwidth? Because DNS sucks.

Actually, strangely enough, both of these use cases work perfectly on my local network, and have worked both with my current router (running dd-wrt) and with my previous router (a standard AT&T combined DSL modem and router).

DNS actually works extremely well with a few, by now ubiquitous, autoconfiguration tools.

^ This.

DD-Wrt and OpenWrt run dnsmasq DNS and DHCP server, which is capable of recording machine names when they request an IPv4 address over DHCP, then DNS-resolving that name to that IP.

And there's also ZeroConf...

The article states that offloading work from routers to clients is useless today because memory and CPU is cheaper due to Moore's law. Well guess what, traffic has increased as well.

What you must think about is "where are the bottlenecks". When you are connecting to a client on the other side of a large network (e.g. the internet) and you're not getting the same amount of bandwidth your last-mile connection should provide you with you have to ask yourself: what's keeping the speed down?

Turns out that router processing is still a bottleneck. And by delegating the mundane router work of handling packet fragments and doing checksum validation to the end terminals we are getting a much more efficient network than with IPv4. IPv6 headers are also much simpler making it easier (faster) to process with ASICs.

Stating that reducing work is useless because we work much faster now than way back when is not a good argument.

I guess NAT is a part of the conspiracy that divides the web into consumers and producers. It's impractical to run services from your home computer, which is why cloud services rake in the money.

I don't know it IPv6 is the solution - if not, lets invent something else.

Check out http://pagekite.net/ , that's my startup and a FOSS project where I am working very hard to accomplish exactly that.

People should be able to run servers on any device. What exactly they will use it for is a mere matter of innovation. :-)

> lets invent something else

telehash.org, for the interim.

I'm getting a growing feeling that the main opposition to IPv6 are the system admins, who are afraid that introducing it will have one of the possible outcomes: either it will bring them more work (billions and billions of addresses!) which they are not familiar with (impossible to remember the address!), or it will make most of them obsolete as most network setup work will be automated. And they're probably right on both accounts (starting with the first and going to the latter).

I hope it does catch on, because until it does, carrier-grade NAT is going to make the lives of security professionals and location-based providers miserable.

To address the shortage of available IP addresses, carriers are going to start giving out RFC1918 (private) IPv4 addresses to their customers. And the NAT could occur anywhere; you might be a customer in San Francisco but the closest public IP gateway could be in New York. (Yes, we have seen this.)

This is going to cause two serious problems for businesses:

(1) Location-based services are going to break. LBS uses the public IP address as the primary key in the database.

(2) DoS protection that is IP-based (counting request rates from particular IPs) is going to break. I suspect a lot more sites that we all know and love are going to have a difficult time staying up after CGNAT is pervasive.

Disclaimer: I am not a sysadmin, but I do tinker with my home computer, doing such things as setting up services like LDAP, NFS, AFS, DNS, mDNS, etc. - so most of this is opinion and stuff I've just picked up along the way.

> The hardware-optimized packet format of IPv6 is worth basically zero to us on modern technology

No. Basically zero is not zero.

> Every HTTP Server on Earth Could Be Sharing a Single IP Address and You Wouldn't Know The Difference

No. Though he lampshades this towards the end, he still gets it wrong - the SNI extensions to TLS allow secured virtual hosting on recent browsers - but not older ones, where it simply just doesn't work.

> if I accidentally leave a daemon running on my server, it's not automatically a security hole

No. NATs are unfairly equated with firewalls. There is nothing stopping a firewall from preventing connections to a computer that is now addressable from the outside, just as they do today. If you are running a publicly-deployed service and do not restrict inbound and outbound traffic, I would advise you to do it, now.

> Because of the way TCP and UDP work, you can safely NAT many, many private addresses onto a single public address

> I won't go into this too much, other than to say that there are already various NAT traversal protocols out there, and as NAT gets more and more annoyingly mandatory, those protocols and implementations are going to get much better.

No. UDP hole-punching isn't that simple. It requires a third party, and implementations of NAT are very heterogeneous. Arguing that it's possible to do safely (and implicitly, on a large scale) is ignoring reality.

So his solution to a newer spec that, despite a rough and in-progress transition, accounts for legacy, is to move to a newer, incomplete, solution that breaks abstraction boundaries, is incompatible with current network hardware, requires major server and router rearchitecture? No. A thousand times no.

> NAT (and DHCP) has largely eliminated another big motivation behind IPv6

No. I find it laughable that he argues that he argues, essentially, that private IP subnets make handling DNS simple, while simultaneously (later) arguing that DNS service records should be used so people don't have to remember IPs + ports, while also saying "So here's what I really hate about IPv6: 16-byte (32 hex digit) addresses are impossible to memorize". How about, instead of kludging up a hack nobody's on board with, using an existing solution with widespread support? Stateless autoconfig or DHCPv6 do the same job.

> If GUIDs were a good idea, we would use them instead of URLs

No. What the ever-living FUCK. Did he not already read his own words about DNS? So sysadmins now have to copy-paste instead of memorizing IPs, or spend a few extra lines in their host files or DNS servers aliasing it to some DNS address. This is a simple and sufficient solution.

> But furthermore, DNS on the Internet is still a steaming pile of hopeless garbage. When I bring my laptop to my friend's house and join his WLAN, why can't he ping it by name? Because DNS sucks. Why doesn't it show up by name in his router control panel so he knows which box is using his bandwidth? Because DNS sucks. Why can the Windows server browse list see it by name (sometimes, after a random delay, if you're lucky), even though DNS can't? Because they got sick of DNS and wrote something that works.

> Of course, I can't really take credit for this idea. It's already been invented and is being used in a few places. (links to wikipedia article on SRV records)

No. JESUS CHRIST. s/because DNS sucks/because Windows sucks/ - for some of the stuff he's talking about, multicast DNS fixed. Oh, and by the way, Bonjour has been using multicast DNS + SRV records for freakin' years, and works pleasantly on !Windows - and it does so for IPv6, as well. I can't speak for Windows because I have had the pleasure of not using it for anything other than games for the past several years. I have set up a Time Machine service on a FreeBSD box that advertised itself as such with no problem whatsoever.

> IPv4 addresses aren't really 32-bits. They're actually 48 bits: a 32-bit IP address plus a 16-bit port number

No! This is like saying that your keyboard and mouse are actually a mouseboard, because they're almost always together. IPv6 still uses TCP - doing what he suggests would not only be a massive kludge, it would obsolete an incredible amount of infrastructure already in place - this cannot be implemented incrementally! Throwing the bathtub out with the bathwater in order to destroy a working layer of abstraction is insane!

> This proposal has very minor chicken-and-egg problems No! Unless by 'minor' you mean bigger than the fucking universe.

This article is founded on so many faulty premises it proposes a technologically intensive non-solution to a problem that suffers from much worse flaws the solution it complains about. Readers should disregard any and all advice proffered by this blog post, as it is grossly inaccurate and incorrect.

And yet, IPV6 adoption is still an insignificant fraction of the IP universe. If not for the reasons given, then why?

> IPv4 addresses aren't really 32-bits; they're actually 48 bits: a 32-bit IP-address plus a 16-bit port number.

> No!

Last time I tried to bind a socket to just an IPv4 address I got a compilation error.

Maybe so, but the port number is part of TCP, not IP.

Use the SOCK_RAW flag on the socket() call and you obviously don't need a bind() call.

I'd like to offer another possible view: Maybe IPv6 will be a great filter on the internet.

All the subpar websites I don't want to be bothered by won't switch, and I won't have to deal with them.

I use similar logic, if a merchant doesn't take Amex I probably don't want to shop there.

If you ever have reason to travel to Europe, this is not a good strategy to follow...

Re: DNS configuration. Zeroconf works. It may not be ubiquitous yet, but it works.

I'm curious how ubiquitous ZeroConf actually is. Every user that has iTunes installed will generally have Zeroconf/bonjour installed as well. Based on the number of iPhone, iPad, and iPod users alone it should be a fairly significant number.

It's cute how he end his long list of messy hacks for dealing with NAT with "Appreciate the astonishing long-lasting simplicity".

Another issue with NAT in large scale deployments is the limited number of simultaneous connections possible. I believe this was best demonstrated by the screenshots of how Google Maps starts degrading when you drop the connections available; 15 saw marked degradation, and that was without any other software running. Can't remember the source of this though now.

I suspect the following:

IPv4 is going to last quite a bit longer once we start trading in IP space. Didn't Microsoft just purchase a huge chunk of IP addresses from Nortel the other day? If that kind of thing is allowed to continue, we're in for years without any need for IPv6 - sadly.

Surely IPv6 clients also have IPv4 interfaces too, don't they already request a AAAA address first and then a A address if that fails? [I'm not sure if they do currently - but seems to make sense]

I wrote my thesis about IPv6 and it's great! (IPv6, not my thesis).

I wonder how much his opinion will change once he starts working for Google...

The guy who wrote this article is going to work for Google? I guess they've drastically changed their hiring practices?

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