Subject: The Implications of 6rd and ARIN 2010-9

From: Marshall Eubanks <[email-masked]>
Date: Tue, 12 Oct 2010 11:06:35 -0400

Hello;

I think that people here would be interested in (and likely
concerned by) the ARIN 2010-9 proposal :

https://www.arin.net/policy/proposals/2010_9.html

"On 15 July 2010 the ARIN Advisory Council (AC) selected "IPv6 for 6rd"
as a  draft policy for adoption discussion on the PPML and at the
Public Policy Meeting in Atlanta in October.

IPv6 for 6rd

6rd is an incremental method for Service Providers to deploy IPv6,
defined in the IETF Standards Track RFC 5969. 6rd has been used
successfully by a number of service providers to deploy IPv6 based
on automatic IPv6 prefix delegation and tunneling over existing IPv4
infrastructure. .... "

What worries me (and others) is that to give end
users an IPv6 /56 will generally require the assignments as short as /24s
to ISPs, due to the encapsulation of v4 addresses inside of v6 addresses :

"The 6rd prefix is an RIR delegated IPv6 prefix. It must encapsulate
an IPv4 address and must be short enough so that a /56 or /60 can be
given to subscribers."

56 - 32 = a /24

If every ISP or other such entity has to get a /24, then there is
room for 2^21 or two million such entities. If, as
seems likely, ISP assignments to users grow to /48's, then the ISP
will need a /16, and that room shrinks dramatically.

Based on this, I (and a bunch of other people on the ARIN PPML list)
oppose this.

I thought it would be wise to bring this to the attention of the
wider IETF community. ARIN discussion of this matter
of course is going on on the [email-masked] list.

Regards
Marshall

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From: Mark Andrews <[email-masked]>
Date: Wed, 13 Oct 2010 10:02:59 +1100

In message <[email-masked]>, Marshall Euba
> an IPv4 address and must be short enough so that a /56 or /60 can be

Only a naive deployment of 6rd would do this. 

If you deploy a 6rd prefix per IPv4 prefix you have allocated and
set appropriate IPv4 mask lengths in your DHCP replies to the 6rd
option request then you have as many /56 as you have IPv4 addresses.
Round up to the next power of 2 and you have the amount of address
space you need to get from your RIR to support your 6rd deployment.

See RFC 5969.

Most ISP's IPv4 address allocations all fall within one or two /8.
That gives a /32 per containing 8 if you a IPv4MaskLen of 8.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: [email-masked]

---

From: Michael Richardson <[email-masked]>
Date: Tue, 12 Oct 2010 21:05:28 -0400

>>>>> "Mark" == Mark Andrews <[email-masked]> writes:
    Mark> In message
    Mark> <[email-masked]>,
    Mark> Marshall Euba nks writes:
    >> "On 15 July 2010 the ARIN Advisory Council (AC) selected "IPv6
    >> for 6rd" as a draft policy for adoption discussion on the PPML
    >> and at the Public Policy Meeting in Atlanta in October.
    >> 
    >> IPv6 for 6rd
    >> 
    >> 6rd is an incremental method for Service Providers to deploy
    >> IPv6, defined in the IETF Standards Track RFC 5969. 6rd has been
    >> used successfully by a number of service providers to deploy IPv6
    >> based on automatic IPv6 prefix delegation and tunneling over
    >> existing IPv4 infrastructure. .... "
    >> 
    >> What worries me (and others) is that to give end users an IPv6
    >> /56 will generally require the assignments as short as /24s to
    >> ISPs, due to the encapsulation of v4 addresses inside of v6
    >> addresses :
    >> 
    >> "The 6rd prefix is an RIR delegated IPv6 prefix. It must
    >> encapsulate an IPv4 address and must be short enough so that a
    >> /56 or /60 can be given to subscribers."
    >> 
    >> 56 - 32 = a /24

    Mark> Only a naive deployment of 6rd would do this.

    Mark> If you deploy a 6rd prefix per IPv4 prefix you have allocated
    Mark> and set appropriate IPv4 mask lengths in your DHCP replies to

I tried to raise this point in April at the ARIN meeting, but it wasn't
understood. 

-- 
]       He who is tired of Weird Al is tired of life!           |  firewalls  [
]   Michael Richardson, Sandelman Software Works, Ottawa, ON    |net architect[
] [email-masked] http://www.sandelman.ottawa.on.ca/ |device driver[
   Kyoto Plus: watch the video <http://www.youtube.com/watch?v=kzx1ycLXQSE>
	               then sign the petition.

---

From: Mark Andrews <[email-masked]>
Date: Wed, 13 Oct 2010 12:47:13 +1100

> I tried to raise this point in April at the ARIN meeting, but it wasn't

Deploying 6rd in parallel with native basically doubles the amount
of IPv6 space required for simple deployments.

Mark

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From: Rémi Després <[email-masked]>
Date: Wed, 13 Oct 2010 15:43:09 +0200

Hi Marshall,
Thanks for this update about ARIN's work.
Comments below.

Le 12 oct. 2010 à 17:06, Marshall Eubanks a écrit :

> ...

Note that the first large scale deployment of native IPv6 (i.e. with LIR provided prefixes), was done with 6rd.
Customers, of which I am, initially had only /64s.
This was because their ISP started with a /32 (the only one it could get quickly, i.e. without arguing about its multi-million customer base), but this was in practice enough for IPv6 to work in typical residential and soho sites.
When Free.fr obtained a /26, our IPv6 prefixes became /60s, i.e. enough for all typical sites that aren't very large private networks (tools.ietf.org/html/rfc5569).

In my understanding,, suggesting that people should have fear, uncertainty, and doubt, about 6rd, is therefore acting against early IPv6-service deployment and use.
IMHO, it's better to encourage them. 

As I personally don't follow ARIN's work, pleas feel free to forward this to your colleagues there.

Regards,
RD

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From: Marshall Eubanks <[email-masked]>
Date: Wed, 13 Oct 2010 15:20:29 -0400

> Only a naive deployment of 6rd would do this. 

Maybe so,  but I was just quoting from the ARIN draft. 

Regards
Marshall