Alternative Re: ipv4/25s and above

Thu Nov 24 03:36:18 UTC 2022

On Tue, Nov 22, 2022 at 8:26 PM Abraham Y. Chen <aychen at avinta.com> wrote:

> Dear Tom: *
>
[...]

>
> 2)   "...Your proposal appears to rely on a specific value in the IP
> option header to create your overlay....": Not really, as soon as the
> 100.64/10 netblock is replaced by the 240/4, each CG-NAT module can
> serve a very large area (such as Tokyo Metro and such) that becomes the
> RAN in EzIP terminology. Since each RAN is tethered from the existing
> Internet core by an umbilical cord operating on one IPv4 public address,
> this is like a kite floating in the sky which is the basic building
> block for the overlaying EzIP Sub-Internet when they expand wide enough
> to begin covering significant areas of the world. Note that throughout
> this entire process, the Option Word mechanism in the IP header does not
> need be used at all. (It turns out that utilizing the CG-NAT
> configuration as the EzIP deployment vehicle, the only time that the
> Option Word may be used is when subscribers in two separate RANs wishing
> to have end-to-end communication, such as direct private eMail exchanges.)
>

Hi Abraham,

I notice you never replied to my earlier questions about EzIP deployment.
I'll assume for the moment that means my concerns were without merit, and
will leave them aside.

But in reading this new message, I find myself again rather confused.

You stated:
"Since each RAN is tethered from the existing Internet core by an umbilical
cord operating on one IPv4 public address,"

I find myself staring at that statement, and puzzling over and over again
at how multi-homing would work in the EzIP world.

Would a given ISP anycast their single global public IPv4 address
to all their upstream providers from all of their edge routers,
and simply trust stable routing in the DFZ to ensure packets arrived
at the correct ingress location to be mapped from the public internet
into the RAN?

Or do you really mean that every RAN will have one giant single point
of failure, a single uplink through which all traffic must pass in order to
reach the DFZ public internet?

If your regional network is a housing subdivision, I can understand the
model of a single uplink connection for it; but for anything much larger,
a single uplink seems like an unsustainable model.  You mention Tokyo Metro
in your message as an example.  What size single uplink do. you think would
be sufficient to support all the users in the Tokyo Metro region?  And how
unhappy would they be if the single router their 1 public IP address lived
on happened to have a hardware failure?

Wouldn't it be better if the proposed model built in support for
multihoming from day one, to provide a similar level of redundancy
to what is currently available on the Internet today?

Or is EzIP designed solely for small, singled-homed residential
customers, and is not intended at all for enterprise customers
who desire a more resilient level of connectivity?

As I noted in my previous message, this seems like an awful lot of
work to go through for relatively little benefit--but this may simply be
due to a lack of essential clue on my part.  I would very much like to
be enlightened.

Thank you!

Matt
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