ISP customer assignments

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1

The address space is daunting in scale as you have noted, but I don't see
any lessons learned in address allocation between IPv6 and IPv4. Consider
as a residential customer, I will be provided a /64, which means each
individual on Earth will have roughly 1 billion addresses each.
Organizations will be provided /48s or smaller, but given the current
issues with routing /48's globally, I think you will find more
organizations fighting for /32s or smaller... so what once was a
astonomical number of addresses that one cannot concieve numerically, soon
becomes much smaller. I can see an IPv7 in the future, and doing it all
over again... I just hope I retire before it comes... The only difference
I can see between IPv4 and IPv6 is how much of a pain it is to type a 128
bit address... Just like back in the day when Class B networks were
handed out like candy, one day we will be figuring out how to put in
emergency allocations on the ARIN listserv for IPv6 because of address
exhaustion and waste.

Food for thought...

Message: 3
Date: Mon, 5 Oct 2009 17:47:12 -0400
From: Dorn Hetzel <dhetzel@gmail.com>
Subject: Re: ISP customer assignments
To: bmanning@vacation.karoshi.com
Cc: NANOG list <nanog@nanog.org>
Message-ID:
<7db2dcf90910051447r5bd7e42fja0b750dceb8d764@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

The estimated mass of our galaxy is around 6x10^42Kg. The mass of earth

is a

little less than 6x10^24Kg.

2^128 is around 3.4x10^38.
So in a flat address space we have about one IPV6 address for every

20,000Kg

in the galaxy or for every 20 picograms in the earth...

One would hope it would last for a while :slight_smile:

considered top posting to irritate a few folks, decided not to.

>
> >Whenever you declare something to be "inexhasutable" all you do is
> >increase demand. Eventually you reach a point where you realize that
> >there is, in fact, a limit to the inexhaustable resource.
>
> This is where I think there is a major disconnect on IPv6. The size
> of the pool is just so large that people just can't wrap their heads
> around it.
>
> 2^128 is enough space for every man, woman and child on the planet to
> have around 4 billion /64s to themselves. Even if we assume

everyone

> might possibly need say 10 /64s per person that still means we are
> covered until the population hits around 2,600,000,000,000,000,000.
>
> Chris
>

        here, you expose a hidebound bias to 20th century networking.
       please remember that - with few exceptions - people network
       at a very different level than machines. people don't need
       IP addresses - computing nodes that want to communicate do.

       Just for grins, put a unique IPv6 address in every active RFID
       tag. ... and remember that there are RFID printers that can
       put 18 tags on a single A4 sheet. Numbers will become

disposible,

2

I'm perplexed. At what size address would people stop worrying about
the "finite" address space? 256 bits? 1024 bits?

I just don't get it. It's not like people get stressed out about running
out of name space in English which is probably more "finite" than ipv6.

Mike

3

Unless you're trying to find a nice, catchy, short domain name. :wink:

But seriously: Many people don't seem to have good intuition about really big numbers. Say, on the order of 2^128. The same thing comes up in discussions about hash collisions in, e.g., content based naming with a 160-bit namespace. I think it's because the numbers are so astronomically big, that without some amount of math and having thought about it with paper and pencil, people automatically scale the #s into terms they can think of as "really big" (like, # of people on earth). So when they think about the 128-bit namespace, they apply intuition that works for a 35-bit namespace...

   -Dave

4

A lesson learned is that thinking about address allocation is something you do not want to spend too many precious seconds of your life on. That's one reason why the space was designed to be so big. Being penny-wise and pound-foolish doesn't really save you much in the IPv6 address space.

Antonio Querubin
808-545-5282 x3003
e-mail/xmpp: tony@lava.net

5

If people start getting /32s because some ISPs are refusing to route /48s, then,
the RIRs are not doing their stewardship job correctly and we should resolve
that issue.

If addresses are handed out according to policies, there is more than enough
space for every individual to have a /48. I think that /56s for residential customers
are probably a good idea and I agree that /48s are usually excessive for residential.

(a /64 is far more than a billion addresses since 32 bits if 4 billion and a /64 is
whatever number 4 billion^2 works out to, basically 16 followed by lots more
digits).

As a residential customer, if you get a /64, then, your ISP is really limiting you
in ways they should not. You should get at least a /56 in most cases.

I think that comparing this to class Bs is kind of absurd, and, I think that the
people talking about lessons learned haven't really analyzed the lessons
very well.

The argument of "lessons learned" usually centers around the idea that
we should regard address space as finite and seek ways to maximize its
use.

The reality is that is not the best lesson. That is what you do when address
space is finite and insufficient and you can't make use of extra bits to do
other optimizations. Therefore, the best lesson to learn is simply that the
IPv4 space was simply not large enough and that we need a much much
much larger space with bits available to do other forms of optimization.

IPv6 does appear to contain that lesson rather well. We have TONS
of bits available on each network for host addressing. So much so that
complicated bizarre subnet address calculations and DNS reverse
delegation difficulties become a thing of the past (look at the hacks
necessary to delegate reverse DNS to 16 different /28 customers
in a /24 block, for example).

In essence, a class B was equivalent to a /56 in its original form, you
could carve it up into 256 /24s. In IPv6, we have plenty of space
to issue /56 and even /48 networks to every small to medium business,
home, etc. and still have lots left over. Large organizations and IPSs
easily get /32s which each contain 65,536 /48s, so, you can divide
your multi-national mega-corp into as many as 65,536 regions and
give each region a /48 and still be OK.

IPv6 offers so much address space that we could give every existing
IPv4 user an entire IPv6 ISP allocation (no, I'm not recommending this)
and still have enough /32s left over in IPv6 to give one to each ISP
and large mega-corp.

Lesson learned... The original address was far too small. The new
address space is actually large enough that this is a pretty good guess
at how to generate addresses that will be fine for decades to come
and still have space left over. In fact, so much so, that, to test the
theory, we're issuing 1/8th of it this way, and, if it doesn't work out
as planned, we can change the allocation policies for the other
7/8ths of the space.

So... Lesson learned... If we had tossed classful addressing
overboard in IPv4 when we allocated 1/8th of the address space,
most of the legacy /8s wouldn't be.

Owen

6

.. address aggregation?
.. convergence time?

I'm sorry, but seeing a good fraction of my local IX simply containing
a few ISP's deaggregated view of their "local" internal networks versus
a sensible allocation policy makes me cry. IPv6 may just make this
worse. IPv6 certainly won't make it "better".

adrian

7

Hey, that's are why logarithms are our friends :slight_smile:

Seriously though, when i was at that big ol' networking company, the size
of the address space was so ridiculously large that hardware and software
people charged with implementing it certainly had no love for it. So it's
not like vendors were cheaping out or something -- it makes their life
quite a bit more, uh, interesting.

Ipv6 *is* what what was learned about ipv4 addresses: make the address
space so astronomically large that nobody could possibly worry.

Curse those logarithms on second thought.

Mike

8

I've been trying to stay out of this discussion because it is pointless, however as I can't help picking at scratching mosquito bites either...

I'm perplexed. At what size address would people stop worrying about
the "finite" address space? 256 bits? 1024 bits?

The issue is that given it is a _finite_ space, its longevity depends exclusively on allocation policy. Since allocation policy is determined by human decision, it is possible (albeit unlikely) that decisions will be made that will result in runout of IPv6 far sooner than one would predict given the vast size of the address space.

To wit, we have already had allocations of a /13, /16s, /19s, /20s, etc., irrespective of the fact that the organizations that obtained those prefixes would likely be unable to make a dent in their allocations by the time the sun burned out (assuming they allocate in a rational fashion). Now, as an exercise to the reader, compare how many of those prefixes exist in IPv6 to how many there are in IPv4...

Regards,
-drc

9

Owen,

If people start getting /32s because some ISPs are refusing to route /48s, then,
the RIRs are not doing their stewardship job correctly and we should resolve
that issue.

Since when do RIRs, good stewards or not, control routing policy of ISPs?

IPv6 offers so much address space that we could give every existing
IPv4 user an entire IPv6 ISP allocation (no, I'm not recommending this)
and still have enough /32s left over in IPv6 to give one to each ISP
and large mega-corp.

Um. How many /32s are their in IPv4? How many /32s are their in IPv6?

Regards,
-drc

10

The fallacy here is the idea that IPv6 has a
128-bit namespace. It does not. It has
two 64 bit namespaces, where one is expected to be globally unique and flat,
While the other is hierarchical.

IPv6 has a lot more room than v4 does, but it is worth noting
Than in v4, a customer would typically use a single /32. In v6-speak, a /48 is a smaller percentage
of the overall space, but it would not be
prudent to view the v6-space as infinite. Remember,
the value of a network increases with the number of interconnections,
and those interconnections are what get numbered.

All of the comparisons to atoms in the galaxy or human population are ignoring the hierarchical element
of the 64-bit space. The nature of hierarchical allocations requires a
Significant &quot;burn&quot; in terms of wasted, unusable addresses.

All that said, the /64-based v6 addressing
approaches are going to be with us for quite a while,
so they&#39;re worth getting used to.

-David Barak

David Andersen wrote:

11

There's a good reason for that: ipv6 isn't intended to do anything
about disaggregation. Which as you rightly point out is a problem in
ipv4 too. IIRC, there was a contingent who thought that address space
and aggregation needed to be considered as a single problem. They
lost the argument and hence ipv6 as it is today and the previously
unsolved aggregation problem... still unsolved.

Mike

12

Of course, that should be "there" in both cases. Wow.

Regards,
-drc

13

From: Robert.E.VanOrmer@frb.gov [mailto:Robert.E.VanOrmer@frb.gov]
Sent: Monday, October 05, 2009 7:41 PM
To: nanog@nanog.org
Subject: Re: ISP customer assignments

The address space is daunting in scale as you have noted, but I don't see

any

lessons learned in address allocation between IPv6 and IPv4. Consider as a
residential customer, I will be provided a /64, which means each individual

on

Earth will have roughly 1 billion addresses each.

Nope. You should get a ~/56. Even so, a /64 gives you ~18BillionBillion
addresses.

Organizations will be provided /48s or smaller, but given the current

issues

with routing /48's globally, I think you will find more organizations

fighting

for /32s or smaller... so what once was a astonomical number of addresses

that

one cannot concieve numerically, soon becomes much smaller. I can see an

IPv7

Nope, organizations will go for PI ~/48s, and Verizon will be forced to stop
filtering them.
Oh, and IIRC - as it stands now, IPv7-9 are already shot (similar to IPv1-3)
... so IPv10 would be next up, in a century ... or four.

in the future, and doing it all over again... I just hope I retire before

it

comes... The only difference I can see between IPv4 and IPv6 is how much of

a

Are you retiring in the next 0-3 years? :slight_smile:

pain it is to type a 128 bit address... Just like back in the day when

Class B

networks were handed out like candy, one day we will be figuring out how to

put

in emergency allocations on the ARIN listserv for IPv6 because of address
exhaustion and waste.

As for the lessons learned - it is about scale.
32 bits isn't enough, double it 96 more times (or 32 more times for just the
network side, if you prefer) and it is enough.

/TJ

14

>The address space is daunting in scale as you have noted, but I don't
>see any lessons learned in address allocation between IPv6 and IPv4.
>Consider

A lesson learned is that thinking about address allocation is
something you do not want to spend too many precious seconds of your life

on.

That's one reason why the space was designed to be so big. Being
penny-wise and pound-foolish doesn't really save you much in the IPv6
address space.

.. address aggregation?
.. convergence time?

I'm sorry, but seeing a good fraction of my local IX simply containing a

few

ISP's deaggregated view of their "local" internal networks versus a

sensible

allocation policy makes me cry. IPv6 may just make this worse. IPv6

certainly

won't make it "better".

Is someone not making sensible use of their IPv6 allocation?
Another one of the goals is to enable organization (and the Internet, prior
to PI space) to be far more aggregatable.
Real example: Instead of one enterprise network having 31 dis-contiguous
IPv4 /16s they could get one (large) IPv6 allocation.
... With room to grow and still aggregate.

PI space changes that conversation on the DFZ side back to a bit of a swamp
until we get that fixed in one fashion or another ...
/TJ

15

Is someone not making sensible use of their IPv6 allocation?
Another one of the goals is to enable organization (and the Internet, prior
to PI space) to be far more aggregatable.
Real example: Instead of one enterprise network having 31 dis-contiguous
IPv4 /16s they could get one (large) IPv6 allocation.
... With room to grow and still aggregate.

PI space changes that conversation on the DFZ side back to a bit of a swamp
until we get that fixed in one fashion or another ...
/TJ

You sure you got the target right? When I look at the the last CIDR
report, top-30 would give a 70% improvement in DFZ. Guess how many end
users with PI are in that top 30?

Tim:>

16

Robert,

I would suggest that some of the lessons we learned are faulty.
Maladaptive. CIDR for instance.

In a classful world, folks who needed a class A got a class A and were
able to announce a class A. They couldn't announce 4200 little
divisions of their addresses like Bell South on last Friday's CIDR
report. CIDR made today's BGP mess possible.

With a larger address space, let's say 128 bits, things *could* have
been partitioned in a such a way that there were enough class B's for
everyone who needed more than a class C and plenty of class-A's for
everyone who needed more than a class B.

There's no doubt that CIDR saved the Internet. There -weren't- enough
IPv4 class B's for everyone who needed more than a class C. CIDR made
it possible to express ranges of class C's as a single route and
that's just the start. But CIDR also created today's problems where it
isn't possible to tell the difference between a route that represents
a unique multihomed endpoint and routes which reflect nothing more
than a bad actor making you pay his traffic engineering cost.

So now Verizon is in open revolt against ARIN. They positively refuse
to carry /48's from legitimately multihomed users. Eff 'em. Perhaps
Verizon would sooner see IPv6 go down in flames than see their TCAMs
fill up again. Who knows their reasoning?

Agree or disagree, it is indeed food for thought. One thing I can say
with confidence: as a community we truly haven't grasped the major
implications of an address space that isn't scarce coupled with a
routing table that is.

Regards,
Bill Herrin

17

So now Verizon is in open revolt against ARIN. They positively refuse
to carry /48's from legitimately multihomed users. Eff 'em. Perhaps
Verizon would sooner see IPv6 go down in flames than see their TCAMs
fill up again. Who knows their reasoning?

Agree or disagree, it is indeed food for thought. One thing I can say
with confidence: as a community we truly haven't grasped the major
implications of an address space that isn't scarce coupled with a
routing table that is.

Thing is, I'm an end user site. I need more that a /48, but probably
less than a /32. Seeing as how we have an AS and PI, PA isn't going to
cut it. What am I supposed to do? ARIN suggested creative subnetting.
We pushed back and got a /41. If IPv6 doesn't scratch an itch, why
bother?

There are plenty of high-profile end user sites in 2620::/23. Some
government (CIA), some popular (Facebook.) I don't think Verizon's
stand is going to last.

Tim:>

18

Tim Durack wrote:

Thing is, I'm an end user site. I need more that a /48, but probably
less than a /32. Seeing as how we have an AS and PI, PA isn't going to
cut it. What am I supposed to do? ARIN suggested creative subnetting.
We pushed back and got a /41. If IPv6 doesn't scratch an itch, why
bother?

We were assigned a /43. insofar as I can tell that's Arin policy working
just fine.

19

joel jaeggli wrote:

Tim Durack wrote:

Thing is, I'm an end user site. I need more that a /48, but probably
less than a /32. Seeing as how we have an AS and PI, PA isn't going to
cut it. What am I supposed to do? ARIN suggested creative subnetting.
We pushed back and got a /41. If IPv6 doesn't scratch an itch, why
bother?

We were assigned a /43. insofar as I can tell that's Arin policy working
just fine.

Mind if I ask what is is so I can see if it's in my Verizon table?
Offlist is fine, I can just post yea/nea to the list.

~Seth

20

From: Robert.E.VanOrmer@frb.gov [mailto:Robert.E.VanOrmer@frb.gov]
Sent: Monday, October 05, 2009 7:41 PM
To: nanog@nanog.org
Subject: Re: ISP customer assignments

Organizations will be provided /48s or smaller, but given the current
issues with routing /48's globally, I think you will find more
organizations fighting for /32s or smaller...

Most organizations will still be assigned a /48 (or whatever) from their
ISP. Provider-aggregable addressing has no routing scalability problems.

I can see between IPv4 and IPv6 is how much of a pain it is to type a 128
bit address...

I have to agree, here. Moving between letters and numbers, and having
to hit "shift" to use the colon wastes valuable keystrokes compared to
the keypad. However, compare IPv6 vs IPv4-like numbering:

2001:db8:f1::1
81.93.35.12.241.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1

Did I type the right number of zeroes?

Lee