AWS Elastic IP architecture

Owen DeLong owen at
Sun May 31 19:11:43 UTC 2015

> On May 31, 2015, at 11:36 AM, Blair Trosper <blair.trosper at> wrote:
> AWS built their network first...before IPv6 "popped", so you can appreciate the huge task
> they have of retrofitting all their products to support it.

Sure, and if they said “We have a plan, and it will take X amount of time”, I would respect that.

If they said “We have a plan and we’re not sure how long it will take”, I would continue to poke
them about sooner is better than later and having a target date helps people to plan.

“We don’t think IPv6 matters and we aren’t announcing any plans to get it implemented or any
date by which it will be available”, on the other hand, being what they have actually repeatedly
said to me until very recently, not so much.

Now, they’re saying (essentially) “We think IPv6 might matter, but we aren’t announcing
any plans to get it implemented or any date by which it will be available” .  To me, this
is still a problematic situation for their customers.

Especially when you look at the impact it has on the rest of the internet.

Review Lee Howard’s Denver ION presentation about per-user-per-year costs of delivering IPv4
over the next several years and it rapidly becomes clear that the failure of Amazon to make dual
stack available is actually one of the major factors preventing eyeball carriers from being able to
make plans for IPv6 monastic on any reasonable timeframe and a major factor in their CGN

> I don't envy the task, but they have said publicly and privately that it's a priority.  But it's
> also a massive undertaking, and you can't expect them to snap their fingers and turn it
> out over a weekend, man…

They haven’t, really, exactly said that. They’ve sort of hinted that they might be working on it
in some places. They’ve sort-a-kind-a paid it some lip service. They haven’t announced plans,
dates, or any firm commitment in any form.

> The prize of being first cuts both ways when newer technologies at lower network levels
> start taking off and you don't have support built in to something proprietary.

I started talking to folks at Amazon about this issue more than 5 years ago. At the time, they
told me flat out that it was not a priority. I gave them half a decade to figure out it was a priority
and do something about it while remaining relatively quite about it publicly. At this point, things
have reached a point where the damage that occurs as a result of applications being deployed
on such a dead-end service and the limitations that service imposes on those applications can
no longer be tolerated.

> Would it be great if they had it faster?  Obviously yes.


> Are they working on it as a priority?  Yes.

Do you have any evidence to support this claim?

> Can they go any faster?  Probably.

Isn’t that answer alone a sign that perhaps it isn’t so much of a priority to them?

> Are there other choices for cloud providers that are full dual stack if this really is a 
> live or die issue for you?  Yes.

This represents one of the most common fallacies in people’s thinking about IPv6.

Your failure to implement IPv6 doesn’t just impact you and your customers. Especially when you’re
something like AWS. It impacts the customers of your customers and their service providers, too.
If Amazon and Skype were IPv6 capable, you would actually find a relatively significant fraction of
traffic that is likely to get CGN’d today would be delivered over IPv6 instead. That’s a HUGE win
and a HUGE cost savings to lots of eyeball ISPs out there. None of them are likely AWS customers.
None of them are likely to be perceived by AWS as “demand” for IPv6, yet, they are in fact the
source of the majority of the demand.

> Access to dual-stack isn't a fundamental human right.  If you don't like what AWS is doing,
> then use someone else who has dualstack.

Again, you are ignoring the larger consequences of their failure.

You can rest assured that I am not purchasing service from AWS due to their failed policies toward IPv6.

However, that doesn’t fully mitigate the impact to me from those bad decisions. So, in an effort to both further
mitigate those impacts and to help others avoid them, I have started vocally encouraging people to take a
serious look at AWS’ lack of IPv6 and consider alternatives when selecting a cloud hosting provider.

> I don't get the outrage...and it's so irrational, that you've caused me to actually *defend* AWS.

I hope I have explained the reasons for my position a bit better so that you no longer feel the need to do so.

I am not outraged by AWS’ actions. They are free to do what they wish. However, I want to make sure that
application developers are aware of the impact this has on their application, should they choose to deploy
it in AWS and I want to encourage current users of AWS to consider IPv6-capable alternatives for the good
of the internet.


> bt
> On Sun, May 31, 2015 at 1:29 PM, Matthew Kaufman <matthew at <mailto:matthew at>> wrote:
> Since your network has IPv6, I fail to see the issue.
> Nobody is anywhere near being able to go single-stack on IPv6, so AWS is just another network your customers will continue to reach over v4. So what?
> Heck, if v6 support from a cloud hosting company is so important, I see a great business opportunity in your future.
> Matthew Kaufman
> (Sent from my iPhone)
> > On May 31, 2015, at 10:57 AM, Owen DeLong <owen at <mailto:owen at>> wrote:
> >
> > Sigh…
> >
> > IPv6 has huge utility.
> >
> > AWS’ implementation of IPv6 is brain-dead and mostly useless for most applications.
> >
> > I think if you will review my track record over the last 5+ years, you will plainly see that I am fully aware of the utility and need for IPv6.
> >
> > <> < <>>
> >
> > My network (AS1734) is fully dual-stacked, unlike AWS.
> >
> > If AWS is so convinced of the utility of IPv6, why do they continue to refuse to do a real implementation that provides IPv6 capabilities to users of their current architecture.
> >
> > Currently, on AWS, the only IPv6 is via ELB for classic EC2 hosts. You cannot put a native IPv6 address on an AWS virtual server at all (EC2 or VPC). Unless your application is satisfied by running an IPv4-only web server which has an IPv6 VIP proxy in front of it with some extra headers added by the proxy to help you parse out the actual source address of the connection, then your application cannot use IPv6 on AWS.
> >
> > As such, I stand by my statement that there is effectively no meaningful support for IPv6 in AWS, period.
> >
> > AWS may disagree and think that ELB for classic EC2 is somehow meaningful, but their lack of other support for any of their modern architectures and the fact that they are in the process of phasing out classic EC2 makes me think that’s a pretty hard case to make.
> >
> > Owen
> >
> >> On May 31, 2015, at 9:01 AM, Blair Trosper <blair.trosper at <mailto:blair.trosper at>> wrote:
> >>
> >> Disagree, and so does AWS.  IPv6 has a huge utility:  being a universal, inter-region management network (a network that unites traffic between regions on public and private netblocks).   Plus, at least the CDN and ELBs should be dual-stack, since more and more ISPs are turning on IPv6.
> >>
> >> On Sun, May 31, 2015 at 8:40 AM, Owen DeLong <owen at <mailto:owen at> <mailto:owen at <mailto:owen at>>> wrote:
> >> I wasn’t being specific about VPC vs. Classic.
> >>
> >> The support for IPv6 in Classic is extremely limited and basically useless for 99+% of applications.
> >>
> >> I would argue that there is, therefore, effectively no meaningful support for IPv6 in AWS, period.
> >>
> >> What you describe below seems to me that it would only make the situation I described worse, not better in the VPC world.
> >>
> >> Owen
> >>
> >>> On May 31, 2015, at 4:23 AM, Andras Toth <diosbejgli at <mailto:diosbejgli at> <mailto:diosbejgli at <mailto:diosbejgli at>>> wrote:
> >>>
> >>> Congratulations for missing the point Matt, when I sent my email
> >>> (which by the way went for moderation) there wasn't a discussion about
> >>> Classic vs VPC yet. The discussion was "no ipv6 in AWS" which is not
> >>> true as I mentioned in my previous email. I did not state it works
> >>> everywhere, but it does work.
> >>>
> >>> In fact as Owen mentioned the following, I assumed he is talking about
> >>> Classic because this statement is only true there. In VPC you can
> >>> define your own IP subnets and it can overlap with other customers, so
> >>> basically everyone can have their own <> < <>> for example.
> >>> "They are known to be running multiple copies of RFC-1918 in disparate
> >>> localities already. In terms of scale, modulo the nightmare that must
> >>> make of their management network and the fragility of what happens
> >>> when company A in datacenter A wants to talk to company A in
> >>> datacenter B and they both have the same 10-NET addresses"
> >>>
> >>> Andras
> >>>
> >>>
> >>>> On Sun, May 31, 2015 at 7:18 PM, Matt Palmer <mpalmer at <mailto:mpalmer at> <mailto:mpalmer at <mailto:mpalmer at>>> wrote:
> >>>>> On Sun, May 31, 2015 at 01:38:05AM +1000, Andras Toth wrote:
> >>>>> Perhaps if that energy which was spent on raging, instead was spent on
> >>>>> a Google search, then all those words would've been unnecessary.
> >>>>>
> >>>>> Official documentation:
> >>>>> <> < <>>
> >>>>
> >>>> Congratulations, you've managed to find exactly the same info as Owen
> >>>> already covered:
> >>>>
> >>>> "Load balancers in a VPC support IPv4 addresses only."
> >>>>
> >>>> and
> >>>>
> >>>> "Load balancers in EC2-Classic support both IPv4 and IPv6 addresses."
> >>>>
> >>>> - Matt
> >

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