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Comment by tptacek | Hacker News Reader

IPv6 is in no sense here. The fiat allocators can exhaust their address space completely and the Internet will continue to function indefinitely; it will simply become more expensive (first marginally, and then significantly) to hold a static address.

There are deep problems with universal deployment of IPv6 far beyond simply getting people to throw a switch; the number of popular software packages that will malfunction when addresses cease being representable in scalar integers is large.

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The internet can only continue to function "indefinitely" as you so put it unless there are no further end points created or demand comes to a grinding halt by users, servers, anything with a public facing IP address. However, that's not the case and many new devices are requiring public facing addresses, and RIR's typically do not give out new blocks until ~3/4 or more (ARIN requires 80%) of the last block they were given is fully utilised. Now for ISP's issuing dynamic assignment to customers that may only happen during peak periods - but if they don't have addresses to give, they along with everyone else that requires public facing IP addresses have two options: more NAT, or IPv6. Quite frankly the idea of being inside an ISP size NAT like many mobile broadband users are on my home DSL connection is quite an unappealing idea.

There are many problems of deploying v6, nobody is saying it'll be a walk in the park, but end devices (like my €100 Nokia dumb phone and my desktop) support it + can also support transitional methods like 6to4, Teredo etc. Tier 1 providers like NTT have been offering it for years - the problem is now the bit in between the end user and tier 1. I think DSL providers with ancient, non-software upgradable DSLAMs (I'm looking at you Ericsson), and the hundreds of millions of home routers out there doing nothing but IPv4 NAT are the bigger challenge than a few bits of code parsing a longer address.

I think that getting home users to upgrade their home routers is easier than getting all of the various software packages out there upgraded to work with IPv6. Getting ISPs to upgrade expensive hardware is another issue...

Which software packages are you talking about, specifically? I seldom encounter libraries or packages that entirely do not support IPv6 (except for MySQL). At the very most it's a configuration flag or compile option to switch it on, if it's not on by default. I'm also curious as to how easy you'll find these homes with a myriad of routers either ISP supplied or third party, and the case you have to convince them that the little box they had needs to be upgraded with firmware or replaced entirely.

The other thing to note is that IPv4 won't just be left in the dust, it'll have to be transitioned - the immediate future at least won't be entirely IPv6, and the world will have a bit of time where dual stack is inevitable for parts.

If cable-companies can figure-out how to transition users from their analog cable boxes to the digital ones, I'm sure ISPs can figure out how to transition their customers to IPv6-capable routers. It should be dead-simple for the ISP-leased routers, but for people with their own routers, it's still an ISP-level issue. They just need to tell their new customers that they need an IPv6 capable router, and to figure out a way to transition existing customers that own their routers.

My cable company lost my business when they last year began requiring a "box" to receive TV. I already had a newer digital-capable TV, and did not want yet another gadget and tangle of wires on my TV stand. It was the final straw, the other two being the cost and the low-value content.

I actually didn't drop them completely, but did fall back to "basic" (no box required) + internet (cheaper than internet alone, which is what I really wanted).

Yeah. The switch to IPv6 will cause lots of things to break. This is unavoidable now.

It's worth noting that on the 8th of June this year, Google, Facebook, Yahoo!, Akamai and others are going dual stack IPv4+IPv6 for a 24 hour period to make people with broken setups aware that they have broken setups. "World IPv6 Day":

https://isoc.org/wp/worldipv6day/

Basically, if you're one of the people with a system which thinks it has IPv6 access but doesn't, then you're not going to be able to access Facebook, Google, Yahoo etc on that day.

The natural solution will be that IPv4 addresses will start getting more and more expensive as they become scarce. At some point, switching to IPv6 will be the cheaper option, and then the switch will happen.

But if you only buy an ipv6 address, the people who are only on ipv4 can't get to you. By itself, the ipv6 address is nearly worthless. The only people who have them now are people who also have an ipv4 address. ipv4 isn't going away any time soon...

Take any prefix thats currently unallocated and make it so that you slap that in front on any ipv4 address.

Volia now everybody has an ipv6 address.

What's wrong with the standard way of doing it? ::127.0.0.1

There's a prefix allocated explicitly for that. The problem isn't getting an address, the problem is getting the software to use it.

Currently IPv4 addresses fix nicely (exactly) into a 32-bit integer. How do you propose that software storing addresses as such will be able to use a larger address without an update? (Not to mention all of the other reasons, like the different packet format to accommodate the larger address space among other things)

Nope, there's always NAT64+DNS64 to rescue.

Well, when ISP hits a cap they either have to get more IPv4 addresses (which they won't be able to do soon) or use some NAT. Except for legacy systems support, NAT64 is clearly a winner here.

NAT64 works fine if you have an ipv6 client and want to talk to ipv6. That's just regular old network address translation. But if your server is on ipv6, NAT64 still needs an ipv4 address so that people there can get to you. The ipv6 address is pointless-- it's easier just to put your server on ipv4 and not mess with NAT64 or ipv6.

Or companies and universities will give up there unused IPv4 addresses so there will be a lot available again. They may even sell them at large prices. But then again, it's just a matter of time before we are really out of IPv4. http://en.wikipedia.org/wiki/IPv4_address_exhaustion#Reclama...

The internet will not function indefinitely. You're forgetting that some of those software packages that are expecting IPv4 addresses also may not function behind a NAT box/router very well or at all.

If your application doesn't work behind an IPv4 NAT box, then your application is broke already. It will likely be broke in IPv6 as well since firewalls are not going away (and many of the same protocols that break because of NAT also break with stateful firewalls).

I'm implying a legacy application that only works with IPv4 addresses, and doesn't work well behind a NAT. I know those are two separate issues, but the transition to IPv6 will likely require those software packages to be rewritten anyways so the idea that it will be broken even on IPv6 is moot because it won't even work on IPv6 as it currently is.

Those most likely are not running against the internet as a whole or at random, or they would be screwed already. VPNs and IPv4 networks that exist today won't disappear...

Why wouldn't they? The IPv4 addresses would either be behind some sort of NAT, or they would be IPv4 addresses in IPv6. If the apps can't handle IPv6, then they can't handle IPv4 addresses in IPv6, and they definitely won't be able to communicate with newer hosts that have IPv6 addresses outside of the range of IPv4.

So the application is broke with IPv4 and NAT, it is broke with IPv6 as it currently is, and somehow in the future it will be able to be re-written in IPv6 and made to work?

Most of the problems that I encounter with NAT and applications deal with protocols that have a control channel and then spawn separate streams frequently which are UDP. H323 is a perfect example. Both ends and the intermediate NAT devices have to understand how to handle the sub-channels.

This problem won't go away with IPv6 as firewalls will still need to understand the sub-flows. Additionally, we will be living in an IPv4 AND IPv6 world with NAT so not only will you likely have to go through an IPv4 NAT you also probably will have to go through a protocol tunneling device for some large set of users.

While it is a big deal, it's really something that needs to happen. I'm hoping that once IPv4 addresses become more and more expensive, that people will start making their content available over IPv6.

There is indeed a very large amount of software that is going to break with the change. Right now, there's little motivation to make your software IPv6 compatible, as everything is either dual stack or IPv4 only. Hopefully news like this makes developers take notice.

I agree. I did a quick check and only 0.19% of the top 1 million sites (according to alexa) have ipv6 enabled:

http://blog.sucuri.net/2011/02/ipv6-is-not-here-yet-in-fact-...

And the biggest issue is that very few people really understand ipv6 to make for a smooth transition..

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