AT&T UVERSE Native IPv6, a HOWTO

Owen DeLong owen at delong.com
Mon Dec 2 21:42:02 UTC 2013


On Dec 2, 2013, at 13:25 , Ricky Beam <jfbeam at gmail.com> wrote:

> On Fri, 29 Nov 2013 08:39:59 -0500, Rob Seastrom <rs at seastrom.com> wrote:
>> So there really is no excuse on AT&T's part for the /60s on uverse 6rd...
> 
> Except for a) greed ("we can *sell* larger slices") and b) demonstrable user want/need.
> 
> How many residential, "home networks", have you seen with more than one subnet?  The typical household (esp Uverse) doesn't even customize the provided router.  Even a CCIE friend of mine has made ZERO changes to his RG -- AT&T turned off WiFi and added the static block at install. (I know NANOG is bad sample as we're all professionals and setup all kinds of weird configurations at "home". I have 3 nets in continuous use... a legacy public subnet from eons ago (I never renumbered), an RFC1918 subnet overlapping that network (because it's too small), and a second RFC1918 net from a second ISP)

Quite a few with at least three out there these days. Many home gateways now come with separate networks for Wired, WiFi, and Guest WiFi.

However, as I have repeatedly said... IPv6 is not about just what we need today. What we need today is limited to what we could do with the scarcity inherent in IPv4 addressing. Restricting IPv6 based on those limitations is absurd.

IPv6 should be about what we want to be able to do in 5, 10, 20, and 50 years. It shouldn't be about what we need today.

> 
> I wouldn't use the word "generous", but a /60 (16 "LAN"s) is way more than what 99% of residential deployments will need for many years.

I'm not so sure about that, depending on how you define "many". Worse, if it becomes the widespread lowest common denominator, then it will become somewhat of a self-fulfilling prophecy in that engineers will design to what users have instead of to what users should be able to get.

>  We've gotten by with a single, randomly changing, dynamic IP for decades.  Until routers come out-of-the-box setup for a dozen networks, non-networking pros aren't going to need it, or even know that it's possible. (and the default firewalling policy in Windows is going to confuse a lot of people when machines start landing in different subnets can "see" each other.)

Yes, we've suffered with a severely degraded internet for decades. Is that really a reason not to make things better going forward? I don't think so.

Routers are already starting to come out of the box with the ability to do prefix delegation and being able to connect multiple routers together into automatically generated hierarchies is a technology that is just beginning to be explored.

Given that Cell Phones and Tablets are already widely used as routers, I don't think that increasing router ubiquity is all that unlikely in the home market in just a few years.

> 
> Handing out /56's like Pez is just wasting address space -- someone *is* paying for that space. Yes, it's waste; giving everyone 256 networks when they're only ever likely to use one or two (or maybe four), is intentionally wasting space you could've assigned to someone else. (or **sold** to someone else :-)) IPv6 may be huge to the power of huge, but it's still finite. People like you are repeating the same mistakes from the early days of IPv4... the difference is, we won't be around when people are cursing us for the way we mismanaged early allocations.  Indeed, a /64 is too little (aka "bare minimum") and far too restrictive, but it works for most simple (default) setups today. Which leads to DHCPv6 PD... a /60 is adequate -- it's the minimal space for the rare cases where multiple nets are desirable or necessary. The option for /56 or even /48 should exist (esp. for "business"), but the need for such large address spaces are an EXCEPTION in residential settings. (and those are probably non-residential users anyway.) [FWIW, HE.net does what they do as marketing. And it works, btw.]

I hate to break it to you, but, no, nobody is really paying for that space. There is no inherent cost to address space relative to the size of the address space. The cost is related to administering the registrations of that space.

Once you get above a certain size, your ARIN fees do not go up.

If you have fewer than 60,000 customers, you can give all of them a /48 for $2000/year. That works out to less than $0.04 per customer per year. If you have fewer than 1,000,000 customers, you can give all of them a /48 for $4,000/year which works out to less than $0.005 per customer per year.

By the way, those numbers leave GENEROUS room for ISP internal infrastructure, overhead, etc. (536 /48s in the first case and 48,576 /48s in the second case).

Arguing that "someone is paying for those addresses" just doesn't work out when you look at the actual costs.

There are enough /48s available in 2000::/3 to give every person alive from now until 2050 16 /48s and still have many left over.

For all of you who keep wanting to repeat the scarcity problems of IPv4 in IPv6 and waste the space by leaving it sitting on the shelf instead of wasting it by handing it out to users, I offer this compromise...

Let's try giving out /48s liberally in 2000::/3. If we exhaust 2000::/3 before I am dead, I will be the first one to help you champion more restrictive policies for the remaining 7/8ths of IPv6. (I expect to live something close to another 50 years and there's not much I can to do help with more restrictive policies beyond my death anyway).

Owen




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