
A brief history of IPv4 address space exhaustion - mmoya
https://blogs.igalia.com/dpino/2017/05/25/ipv4-exhaustion/
======
dboreham
Unfortunately my perception is that IPv6 deployment is stalled (due to
inaction by ISPs). In my company we have recently dismantled some of our IPv6
infrastructure because it became apparent that ubiquitous v6 connectivity was
not coming any time soon (e.g. we have locations served by Charter/Spectrum,
and they have no IPv6 and no plan to deploy it). We've instead deployed a
private IPv4 overlay network between our sites and assets using GRE tunnels.

Also somewhat exasperating that the "running out of IPv4 addresses" saga has
played out across almost my entire career. I remember attending the CIDR
meetings at the IETF in around 1992, for example. So one of the first
technical problems I encountered in my career remains unsolved nearly 30 years
later.

~~~
bpodgursky
I don't think that perception is accurate. Google's IPv6 tracker shows
continual progress:
[https://www.google.com/intl/en/ipv6/statistics.html](https://www.google.com/intl/en/ipv6/statistics.html)
(with the expected bumps around weekends and holidays)

It's not a fast process, but I don't see any evidence it is stalled.

~~~
stouset
I don't think it really matters what percent of clients are IPv6-capable.
Nobody is incentivized to actually deploy _servers_ to IPv6 while there exist
zero IPv6-only clients.

~~~
zkms
> Nobody is incentivized to actually deploy servers to IPv6 while there exist
> zero IPv6-only clients.

Facebook is a counterexample.

> Over the past few years, Facebook has been transitioning its data center
> infrastructure from IPv4 to IPv6. We began by dual-stacking our internal
> network — adding IPv6 to all IPv4 infrastructure — and decided that all new
> data center clusters would be brought online as IPv6-only. We then worked on
> moving all applications and services running in our data centers to use and
> support IPv6. Today, 99 percent of our internal traffic is IPv6 and half of
> our clusters are IPv6-only. We anticipate moving our entire fleet to IPv6
> and retiring the remaining IPv4 clusters over the next few years.

[https://code.facebook.com/posts/635645183305089/legacy-
suppo...](https://code.facebook.com/posts/635645183305089/legacy-support-on-
ipv6-only-infra/)

~~~
stouset
They might have _actually done_ it, but my point is that the incentives for
companies to do so generally aren't there. And as long as there exist some
large sites that believe the costs to adopting IPv6 exceed the benefits, ISPs
will continue to give IPv4 addresses to their clients.

~~~
Symbiote
My phone's IP is in the private 10 range. A request to Facebook must go
through the provider's expensive NAT router.

If they assigned my phone an IPV6 address in addition, that traffic could go
directly to Facebook through cheaper switches, which is faster for me, and
cheaper for them.

------
metalliqaz
I now receive a block of IPv6 from Comcast. I allow the router to assign them
to devices on the network, but I admit that I am somewhat worried that my
local PC is no longer isolated from the Internet by a private IP.

~~~
bArray
I think whilst it's nice to have that barrier, it's prevention rather than
cure anyway. There's no substitute for secure devices :)

~~~
2bitencryption
what's more secure than a device you cannot possibly reach?

I'll take an insecure device isolated at the bottom of the ocean in a titanium
block over a probably-secure device that is publicly addressable any day.

~~~
Spivak
Your appliance 'router' can (and probably does) run a firewall to give you
that kind of control. NAT never really gave you that.

------
FullyFunctional
I find DJB's take on this interesting:
[https://cr.yp.to/djbdns/ipv6mess.html](https://cr.yp.to/djbdns/ipv6mess.html)

EDIT: Dan has many excellent points, but I'd like to quote my favorite:

 _The IPv6 designers made a fundamental conceptual mistake: they designed the
IPv6 address space as an alternative to the IPv4 address space, rather than an
extension to the IPv4 address space._

Indeed, what were they thinking!

It's certainly an undeniable fact that IPv6 adoption has been a disaster,
taking much longer than hoped for. Frankly, I expect to see IPv4 coexist with
IPv6 for the next hundred years - not ideal.

~~~
cesarb
One thing I never understood in these proposals: how would two computers, one
with only an extended address and the other with only an IPv4 address, talk to
each other? Or two computers with extended addresses, but with a single router
in the middle of their path which doesn't understand extended addresses?

All these proposals I've seen appear to assume that extended addresses start
being distributed only after every or almost every host and router in the
whole world had all of its software upgraded to understand extended addresses.
But that's not realistic, since without being able to actually use it, there
would be no incentive to modify every single piece of network-facing software
and hardware to be able to use extended addresses. It's a Catch-22.

~~~
FullyFunctional
There are two issues in migration: updating software and updating
configuration. The former can be completely trivial if you are just pulling
down updates from someone else. The latter requires effort on your part. If
the IPv6 address space had been an extension, then you wouldn't have to do any
configuration to support IPv6 clients while you maintain your existing 32-bit
address, valid for both stacks.

At least that's my understanding of it.

~~~
keeperofdakeys
For a new transport layer protocol like QUIC, this can work. However when you
start talking about IP, you need to update/replace basically every device on
the internet. If a device in the path doesn't know about the extended address
space, that packet probably can't reach it's destination.

~~~
FullyFunctional
? You have to upgrade the software on all devices to move to a larger address
space. That's understood. What we are discussing here is the added complexity
of the configuration. Updating the software is easy by comparison.

------
pololee
When I was at UCLA, I learned this new architecture called NDN [https://named-
data.net/](https://named-data.net/). It does not rely on addressable device or
host. It give addresses to content. Not sure how industry think of this new
idea. I watched several talks about NDN. They all have great stories and
believe it's the future.

~~~
voltagex_
[http://named-data.net/doc/NFD/current/manpages/ndn-
autoconfi...](http://named-data.net/doc/NFD/current/manpages/ndn-
autoconfig.html#ndn-hub-discovery-procedure)

Still relies on TCP and UDP and thus still needs IP addresses.

------
rst
Corrections: CIDR stands for Class _less_ Inter Domain Routing (because it
superseded the Class A/Class B/Class C arrangement, which allowed only three
particular allocation block sizes).

------
porfirium
I know the author is Spanish; I'd like to point out Orange Spain has been
deploying IPv6 addresses to end customers these last weeks using the Dual
Stack lite transition system.

All the big ISPs have been testing IPv6 for years now and I'm sure it's just a
matter of flipping a switch. Now that a new contender is in town (a 4th ISP)
and they're having huge problems because they have no IP addresses left to
assign to their customers, I suppose the rest of ISPs will stall even more
their transition to IPv6 so they can try and "suffocate" the new ISP.

Just my two cents...

------
djsumdog
I've only worked at one company that had full IPv6 support. Even on my current
1GbE fibre setup with a small startup, they still don't have IPv6 rolled out
to residents yet. :(

I feel like one big hurdle is IPv6 usability. You can write down and easily
remember IPv4 addresses. IPv6 netmasks can get really confusing. They make
sense if you expand out every block, but in reality, IPv6 requires a lot of
tooling to chop up and work with address spaces in an intuitive way.

~~~
rschulman
I love it when people make this argument. The IPv6 adoption hurdle is NOT the
usability of v6 addresses. 99% of the world thinks that IPv4 addresses are a
horrorshow and would never bother to memorize one or even write one down. They
use DNS because they are human beings. The layout of the address behind the
DNS they couldn't care less about.

~~~
vidoc
I think you are right, now it would be somehow hard to deny the fact that ipv4
addresses _were_ possible to memorize, ipv6's, quite a bit less so. I agree
that it's a non-issue 99% of the time, and the overwhelming majority of lambda
users _will_ use DNS anyways - that said, when you don't have DNS, are a
sysadmin/engineer or what not, you do feel the pain sometimes :)

------
gwu78
[http://www.internetsociety.org/deploy360/blog/2017/05/google...](http://www.internetsociety.org/deploy360/blog/2017/05/google-
buys-a-12-ipv4-address-block/)

------
bogomipz
If you enjoyed this, this is a great resource current state of prefix
utilization in the global routing tables:

[http://www.cidr-report.org/as2.0/](http://www.cidr-report.org/as2.0/)

------
redm
IPv4 is like any commodity. Now that it's not easily to get from ARIN, a
market has sprung up around buying and selling it.

It's still relatively easy to get IPv4 blocks for a buck or two per IP through
auction houses.

~~~
zlynx
Although whatever block you get has to be big enough to convince people to
route to it. Too small and it won't matter. No ISP wants to carry the load for
millions of tiny IPv4 blocks.

~~~
icedchai
The smallest you can get is a /24, and everyone accepts routes for that.

In 1997, I remember running 2 T1's w/BGP on a router with a whopping 32 megs
of RAM. I think there were 50,000 routes! How things have changed...

------
bArray
Would have been awfully nice to have a reserved bit in hindsight. 7 bit ASCII
was an amazing accident. (Maybe it wasn't, time to brush up on my history...)

~~~
dogecoinbase
We do/did! Class E space (240.0.0.0/4) exists and is entirely unused. There
was a proposal in 2008-ish to try and convert it to regular IP space for
allocation, but the agreement was that it would be too much work (many stacks
default drop class E packets) and we should focus on transitioning to IPv6.

~~~
bArray
Thanks, I wasn't really aware of this. Class E wouldn't add too much to the IP
address space if I understand this correctly?

I was thinking more along the lines of a bit being flipped would mean the next
8 bytes are an IP and not four, for example.

From my limited understanding, I don't think they reserved a bit in the
address space?

------
gens
IANA sold the blocks. There are still a lot of unused IPv4 addresses. IANA
sold the blocks.

PS IPv6 sucks.

~~~
jcranmer
The IANA blocks were exhausted in January 2011. All of the RIRs save AFRINIC
exhausted their internal allocation pools since then: APNIC in April 2011,
RIPE September 2012, LACNIC June 2014, and ARIN September 2015 (although note
that the definition of "exhaustion" differs from RIR to RIR--ARIN in
particularly relied on a truly-bone-dry definition whereas APNIC claimed
exhaustion when they had less then a full /8 in their pool).

As of right now, ARIN appears to have exactly 0 IPv4 addresses--they can't
even give out a block of 256 IPv4 addresses to someone who asks for it. All
they can do is put you on a waiting list until someone else agrees to give up
their IPv4 address space. Some people have been waiting since July 2015.

------
exabrial
We only use 32 bits of each 48 bit ipv4 address. The problem isn't exhaustion,
it's using DNS to do service location rather than IP.

~~~
syncsynchalt
If you mean ports, those aren't IP. Those are TCP/UDP.

