[156721] in North American Network Operators' Group

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Re: Throw me a IPv6 bone (sort of was IPv6 ignorance)

daemon@ATHENA.MIT.EDU (Mike Jones)
Mon Sep 24 17:43:58 2012

In-Reply-To: <7B6B102F-E054-4D62-B7D3-20D859C3A33A@logic.org.uk>
From: Mike Jones <mike@mikejones.in>
Date: Mon, 24 Sep 2012 22:42:46 +0100
To: Adrian Bool <aid@logic.org.uk>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org

On 24 September 2012 21:11, Adrian Bool <aid@logic.org.uk> wrote:
>
> On 24 Sep 2012, at 17:57, Tore Anderson <tore.anderson@redpill-linpro.com=
> wrote:
>
>> * Tore Anderson
>>
>>> I would pay very close attention to MAP/4RD.
>>
>> FYI, Mark Townsley had a great presentation about MAP at RIPE65 today,
>> it's 35 minutes you won't regret spending:
>>
>> https://ripe65.ripe.net/archives/video/5
>> https://ripe65.ripe.net/presentations/91-townsley-map-ripe65-ams-sept-24=
-2012.pdf
>
> Interesting video; thanks for posting the link.
>
> This does seem a strange proposal though.  My understanding from the vide=
o is that it is a technology to help not with the deployment of IPv6 but wi=
th the scarcity of IPv4 addresses.  In summary; it simply allows a number o=
f users (e.g. 1024) to share a single public IPv4 address.
>
> My feeling is therefore, why are the IPv4 packets to/from the end user be=
ing either encapsulated or translated into IPv6 - why do they not simply re=
main as IPv4 packets?
>
> If the data is kept as IPv4, this seems to come down to just two changes,
>
> * The ISP's router to which the user connects being able to route packets=
 on routes that go beyond the IP address and into the port number field of =
TCP/UDP.
> * A CE router being instructed to constrain itself to using a limited set=
 of ports on the WAN side in its NAT44 implementation.
>
> Why all the IPv6 shenanigans complicating matters?

While you could do something similar without the encapsulation this
would require that every router on your network support routing on
port numbers, by using IPv6 packets it can be routed around your
network by existing routers. And it's not like anyone is going to be
deploying such a system without also deploying IPv6, so it's not
adding any additional requirements doing it that way.

- Mike


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