[alyrik]

I agree... the problem is, how are we to get a single global namespace?

I have serious concerns with IPv6's practicality, even with 6in4 et al. Is trying to implement it just flogging a dead horse?

If somebody comes up with a way to actually get IPv6-only nodes widespread - not just nodes with joint IPv4 and IPv6 machines - then I'll have hope for mainstream IPv6. But while every client and server has to have IPv4 as well to be of any use, then what benefit does having IPv6 connectivity give it?

[wladimir]

How is it a dead horse? Many ISPs are working on implementing IPv6. Some ISPs here in the Netherland have been offering it for quite a long time. Large sites (Google, Facebook, etc) are also slowly adapting it.

Yes, the transition is going very very slowly. But I don't think there is a problem. One could argue it's the same with IPv4 addresses as with oil. Eventually, it will get more expensive as it gets more scarce, and people will gradually switch to alternatives.

At a certain moment all the important sites will have adapted IPv6 that it's economical for some users to drop expensive IPv4. Sites will then hurry to go to IPv6 as they lose customers. But I guess there's no need to hurry yet... at least for us IPv4-rich western countries.

[alyrik]

I've seen the "IPv4 will get more and more expensive, and more and more sites will provide IPv6 connectivity, and (for some unspecified reason) clients will put out the effort to get IPv6 connectivity for no near-term benefit, and then when nearly everyone has IPv6 connectivity, IPv4 support will become like IE4 support and sites will start dropping it, and the IPv4-only people will then demand an upgrade" argument, and I think it has flaws.

* Why do clients - home ADSL users, small offices, wifi hotspots - want to bother with IPv6? It offers them no benefit for at least several years. Everything that's good is IPv4 only, or maybe IPv4 and IPv6. All they need is one external IPv4 - or they can share an upstream IPv4 via carrier-grade NAT, so they needn't bear any "rising cost" of IPv4.

* Why should important sites really bother about IPv6? They already have large IPv4 allocations, and there's endless tricks to make better use of them (they can vhost any HTTP-based service, for a start). Moving to IPv6 will make it easier for startups to get IPs to compete with them. I'm not sure why some of them have offered limited IPv6 access (Facebook's is just a proxy that forwards on the connections via IPv4, it seems), but they don't seem to maintain them well (bit.ly was inaccessible via IPv6 all day; nobody seemed to notice) - I suspect they're mainly "20% time" projects.

* Just how near is the point where it's a good idea to drop IPv4, for clients or servers? There's a lot of legacy networks to shift... more so on the client end than on the server end, which is dominated by a "top 100 sites" or so that could all conceivably add IPv6 support with little effort.

[wladimir]

Hey, I'm explicitly saying in my post that there is no hurry. It could still take ages. Maybe 20 years. But eventually we need more addresses than IPv4 can provide. Hacks such as NAT will make the IPv4 range a bit more stretchable, but they don't scale and won't hold up forever.

I know what the current state of affairs is. I don't understand why all the "IPv6 is not widely adopted yet so let's rationalize it as if we'll be on IPv4 forever" posts on HN lately. It is a slow, gradual process. If you don't want to worry about it yet then just don't.

Back when 64 bit CPUs were entering the consumer realm, you also had people saying "Man, addresses will take two times as much space and who needs to address that amount of memory? And there are plenty of memory mapping tricks to keep us on 32-bit for a long time"...

[Retric]

IPv6 is vary useful for peer to peer communication such as torrents and skype. My roommate and I sit behind NAT and rather than choosing a single PC that get's fast torrent downloads IPv6 can gradually increase the number of peers other PC's can see. Even better the speed scales up as adoption increases. Also, when you want remote into a more than one home PC you can do so directly with IPv6, you don't need to pick a single host and then remote into other machines on your network.

The only downside is you need better firewalls.

[alyrik]

Yeah, I'd like easier peer-to-peer communications, too.

Which is why I suggested setting up SOCKS as a competitor to NAT, as it lets the client ask the gateway device for an external IP/PORT to do peer-to-peer communications over... without needing to set up IPv6 :-)