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Comment by andyking | Hacker News Reader

This seems to have been rumbling on for some time now - at least for the past five years or so.

My OS supports IPv6, my home router supports IPv6, but at no point have any of the home ISPs I've used (three in the past five years - BT Internet, Be and Origin Broadband) made any mention of any sort of IPv6 support.

I'm not au fait with the workings of such huge operations, so is there any reason for ISP adoption of IPv6 to be so sluggish? It's not like it's been an overnight thing. I'm aware it's unlikely to be a simple case of flipping a switch, or installing a new software package - but we do appear to be approaching an IP crunch.

Are there any consumer ISPs that do offer customers a block of IPv6 addresses for use, rather than (or as well as) a single IPv4 address?

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> Are there any consumer ISPs that do offer customers a block of IPv6 addresses for use, rather than (or as well as) a single IPv4 address?

Comcast, at least in some parts of the country (e.g. SF's East Bay). You don't even have to ask them. One day I noticed my router was being advertised an IPv6 route. I switched on DHCPv6 and got an IPv6 address, as well as a /64 prefix for the rest of my network.

Unfortunately /64 is all you can get for now, which isn't really sufficient, but they've promised to delegate shorter prefixes in the future.

"Unfortunately /64 is all you can get for now, which isn't really sufficient"

Not sufficient for what? (Honest question.)

yeah, a /64 is more than 2^32 times more than all of current internet... i don't think the GP really meant 'sufficient', or i'm missing something.

a /64 gives you a single subnet with effectively infinite size. A shorter prefix would allow you to have multiple subnets for isolating things like gaming devices, guest networks, VPNs, etc. For IPv4 the ability to do this was basically a pipe dream, for IPv6 the addresses are there, we just need to coordinate how ISPs hand them out and how consumer routers manage them.

In short, one /64 is sufficient for duplicating an IPv4 like situation. A /60 or /56 gives us more room to innovate in new types of home networks.

Sufficient to have more than one subnet. In IPv6 you can't easily have a subnet that's smaller than /64, so even though /64 = 2^64 addresses, it's still just a single subnet. In IPv6, we need to start thinking in terms of number of subnets rather than number of IP addresses.

Why is having one subnet insufficient? I use multiple subnets (I have a guest network), and I don't want to have to use NAT with IPv6 when my ISP has effectively infinite address space. Of course, I'm not an average user, but remember that 10 years ago only power users had home routers, and for everyone else 1 IP address was enough. Now everyone has a router. There are already some consumer access points that tout a "guest network" as a selling point, and there may be other consumer uses for multiple subnets in the future.

a /65 is a subnet, and you get TWO of them with a /64. And so on. So I don't really understand what you're talking about here.

In theory, you're right. But in practice, IPv6 really wants subnets to be /64. For example, stateless address autoconfiguration requires it.

It truly is saddening how we're treating v6

I agree. It seems like we're setting up the IPv6 address space to be wasted.

Actually, there's a good reason why IPv6 subnets are so large - it's because with stateless auto configuration, the lower bits (the "Interface ID") of the address are derived from the MAC address, which is 48 bits.[1] (Stateless auto configuration is brilliant because, despite being stateless (unlike DHCP), no two devices will ever be assigned the same IP address on a subnet.) 48 < 64, so technically the subnet size could be /80 instead of /64, but does 16 bits really matter in the grand scheme of things, especially when there are 2^64 /64's available?

Another way of looking at this is that IPv6 could have been just IPv4 with 64 bit addresses, and we would have been fine. However, the designers decided to add stateless auto configuration, and added another 64 bits to make it work.

[1] In privacy mode, the Interface ID is generated randomly instead of from the MAC address (to prevent tracking by MAC address). In this case, you still need lots of bits to make the probability of a collision insignificant.

NAT will never disappear.

You're probably right, and one easily preventible reason will be ISPs giving out too-small or dynamic prefix assignments. There may be legitimate reasons for IPv6 NAT, but this isn't one of them.

> This seems to have been rumbling on for some time now - at least for the past five years or so. ... It's not like it's been an overnight thing.

To say the least! This particular rumble ("we're out!") may be new-ish in the last few years, but the general rumble ("we'll run out!") has been going on a lot longer, and the transition is pretty much the opposite of an overnight thing. I learned about how IPv6 was imminently needed and right around the corner when I took a networks class in college. In 1996. Tanenbaum's book (from four editions ago!) includes ten pages on IPv6 that could appear in a book published today nearly unchanged.

My ISP (Andrews&Arnold, UK) offer IPv6, so I have a /48 and (since I bought a new modem recently) all my machines are now natively IPv6 with no tunnelling involved. (A&A also support tunnelling if your modem/router is IPv4 only.)

Excellent. I currently use a local ISP, because it's the only way I can get a decent speed where I live (there's a local FTTC network called Digital Region).

But I'm likely to be moving out of their coverage area at some point, so I'll add this to my list to consider when I do. Thanks!

Eircom (an Irish ISP) are trialing IPv6 currently, and the routers they have been shipping for the last year or so support it.

Other than that, our co-location provider Blacknight offer IPv6 to their customers.. but that's not exactly residential!

BT / Esat were trialling IPv6 as early as 2005 and giving native allocations around that time also

I'm in the opposite situation.

My ISP and wifi router support IPv6; but my modem does not. And without this modem failing, I probably won't shell out $150 for a new one.

According to [1] there are a few - no big names, though. As [2] says, running IPv6 is fairly boring; you get access to the same web as everyone else.

[1] http://www.sixxs.net/faq/connectivity/?faq=native&countr... [2] http://bens.me.uk/2011/adventures-in-ipv6

I'm running on IPv6 on Comcast in the US, and yes while I get access to the same web, I have noticed that I was having issues with IPv4 that I don't have on IPv6. Such as limits per IP/account tuple logged into certain servers.

So my iPad, iPhone, and MacBook Pro being logged into the same Google account over IMAP would sometimes cause issues because of too many connections for that specific account, now with IPv6 that isn't an issue because all of my devices now have their own unique IPv6 address. Perfect.

[2]'s comment "you get access to the same web as everyone else" really only applies to consumers of "the web".

And - more importantly - soon no longer applies even to that. IPv4 is essentially gone, and when it is, not having IPv6 will mean your web is smaller.

IPv6 gives you much more freedom in configuring your network as both a service provider and consumer. This isn't boring :)

I'm not sure about other places, but I wrote some software for an ISP in Poland. It seems damn hard to coordinate whole country worth of people in normal operation, leave alone make a transition to new technology. Remember that many people won't be happy with transient trouble related to the switch.

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