Subject: Re: Consensus Call: draft-weil-shared-transition-space-request

From: [email-masked] (Noel Chiappa)
Date: Sun, 4 Dec 2011 10:55:27 -0500 (EST)

> From: Mark Andrews <[email-masked]>

    > The CGN boxes are new. The customer boxes which are being allocated the
    > addresses are old. Lots of these boxes will not work with a 240/4
    > address.

Here's a question, though: would a mix of a smaller block of 'classic' IPv4
space, _along with_ a big chunk of 240/4, be of any use?

I ask because I gather there are a lot of situations where e.g. a cable modem
has an ISP-local address on its ISP-facing side, and a global IP address
(which the customer gets) on the customer side. (I see this in checking out my
path to the Internet from my house - I see some 10.xx addresses on the other
side of the cable modem.) Could a block of 240/ space be used for things like
that?

Sure, the 240/ space wouldn't be useful as a source of addresses for
_customer-owned_ equipment - but could it be useful elsewhere inside an ISP's
network? (And perhaps also as a source of addresses for CPE equipment which
_will_ tolerate being given a 240/ space address, although I concede that may
be very few boxes, at least at first.)

	Noel

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From: Victor Kuarsingh <[email-masked]>
Date: Sun, 04 Dec 2011 11:09:12 -0500

Noel,

>side of the cable modem.) Could a block of 240/ space be used for things

This is a cable specific use case based on your comments.  I would
separate the CM (Modem) IP address and function from the customer (CPE)
addressing function.  I don't think ISPs have specifically claimed issues
with CM addressing but for the CPE customer side.

Also, consider the CM address ranges as somewhat transparent to the CPEs
needs getting to the Internet.  Although you may see evidence of the space
by a traceroute, it serves no direct purpose for you Internet flow (I.e.
Your next hop address from your CPE will be the CMTS interface/IP in most
cases).

So, back to your point, whereas 240/4 may be somewhat usable on the CM
side in the future, the CPE space is what's in question here.

Regards,

Victor K

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From: Mark Andrews <[email-masked]>
Date: Mon, 05 Dec 2011 09:44:45 +1100

In message <[email-masked]>, Noel Chiappa write
> be very few boxes, at least at first.)

I suspect most Cable ISP's will do what Comcast is doing and migrate
to IPv6 for management of the modems.  DOCSIS 3 modems support IPv6
and I believe some DOCSIS 2 modems also support IPv6 with newer
firmware.  This part will fix itself as modems fail and are replaced
as long as you require the new cable modem to support IPv6 on the
management side.  You can deal with the few customers bringing their
old modem with them as they move between providers.

That said I'm not employed by a Cable ISP and the cable modem at
home is a DOCSIS 1 box.

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