Subject: RE: new draft on IPv6 CPE router available for review

From: "Wes Beebee (wbeebee)" <[email-masked]>
Date: Mon, 30 Jun 2008 14:47:06 -0400

Mikael - 

Thanks for this review.  Your comment makes a lot of sense. 

We would be happy to incorporate your suggestion into our draft.

- Wes and Hemant

-----Original Message-----
From: Mikael Abrahamsson [mailto:[email-masked]] 
Sent: Monday, June 30, 2008 2:24 PM
To: Wes Beebee (wbeebee)
Cc: Hemant Singh (shemant)
Subject: Re: new draft on IPv6 CPE router available for review

On Mon, 30 Jun 2008, Wes Beebee (wbeebee) wrote:

> v6ops folks,
>
> Please review this draft.
>
> http://www.ietf.org/internet-drafts/draft-wbeebee-ipv6-cpe-router-00.t
> xt
>
> The Abstract of the draft is snipped below.
>
> Abstract
>
>   This document recommends IPv6 behavior for Customer Premises
>   Equipment (CPE) routers in Internet-enabled homes and small offices.
>
>
> Thanks.
>
> Hemant & Wes.

Hello.

In section 5.3 I would definitely like a CPE to work without having a
WAN address (link local only). The rationale behind this is that we
would like ISP routers have IPs in a core IP-range (which will be
protected from DDOS by ratelimiters or filters) and have customers in
their own IP space. The handoff between distribution and CPE should be
done via something that is not reachable from the internet, ie the CPE
should never source packets from its WAN IP, instead it should source
packets destined to the internet from a loopback IP which it should
allocate to itself from DHCPv6-PD (it could also be a LAN interface IP).
So behavior would be "get link-local working, do DHCPv6-PD, allocate IP
to itself from PD range, then use THAT to provision itself further and
to communicate with everything".

>From what I read in 5.3, this behaviour would be in violation of the
draft you've written, so I would like your input on how my thoughts
above could be incorporated into your draft (which I think is an
excellent initiative).

Regards,

-- 
Mikael Abrahamsson    email: [email-masked]

---

From: Shin Miyakawa <[email-masked]>
Date: Tue, 01 Jul 2008 10:20:44 +0900 (JST)

Hello,

I have a comment on the transfered message by Wes,

> WAN address (link local only). 

Actually, this does not work if a CPE use the strong host model implementation
describing in RFC1122 or STD3 : Requirements for Internet Hosts - Communication Layers.

> The rationale behind this is that we would like ISP routers have IPs 
> in a core IP-range (which will be protected from DDOS by ratelimiters or filters) 
> and have customers in their own IP space. 
> The handoff between distribution and CPE should be

Originally, when we wrote RFC4241 (A Model of IPv6/IPv4 Dual Stack Internet 
Access Service) to start our IPv6/v4 dual stack native ADSL service, 
we also thought about same thing. So we can understand Mikael's will too.

But now Microsoft Vista and Windows 2008 IPv6 implementation are based on 
the strong host model as default, (please see 
http://technet.microsoft.com/en-us/library/bb878108.aspx
and
http://technet.microsoft.com/en-us/magazine/cc137807.aspx ).

Especially, if we think that the uplink is a "softwire" or the CPE is a brige,
Vista is one of the most likely to be used operating systems 
to terminate the IPv6 uplink by itself, so 
from practical point of view, we strongly recommend to assign a global IPv6 address.

We've just submitted a very short draft regarding this issue

http://www.ietf.org/internet-drafts/draft-miyakawa-1plus64s-00.txt

and hope this could be merged to the section 5.3 of Wes's draft with its reasons.

Best regards,

Shin Miyakawa, Ph.D
Director, Core Network Technology Team, Network Systems and Technologies, 
Innovative IP Architecture Center /
Corporate Planning Department (concurrent position)
NTT Communications Corporation
Tokyo Opera City Tower 21st Floor
3-20-2 Nishi-Shinjuku, Shinjuku-Ku, Tokyo, Japan 163-1421
E-mail:[email-masked] / [email-masked] / [email-masked]
TEL:+81-3-6800-3262 / FAX:+81-3-5365-2990
Visiting Researcher, SFC Lab. KEIO University
WIDE Project

---

From: Mikael Abrahamsson <[email-masked]>
Date: Tue, 1 Jul 2008 08:53:45 +0200 (CEST)

On Tue, 1 Jul 2008, Shin Miyakawa wrote:

> to terminate the IPv6 uplink by itself, so from practical point of view, 
> we strongly recommend to assign a global IPv6 address.

Well, my personal opinion is that this makes Vista unfit to be a IPv6 CPE. 
We cannot adjust IPv6 address policy just because of certain design 
decisions on behalf of Microsoft.

It is my belief that customers (at least in the market I am in) will need 
to have a small CPE that is not an end host, and this is what the draft 
should be aimed at. Advocating PPP is also a very bad idea as this cements 
the use of LAC/LNS and tunneling, which is a really bad idea for future 
multicast use, as well as being more expensive than necessary.

My idea of a good IPv6 service is one that is purely IPv6 over ethernet, 
optionally with 1-2 q tags or mac-in-mac in the ISP part of the network, 
but definitely not involving PPP or L2TP anywhere in the path.

At least, how can we make the draft comply so that what I would like to do 
doesn't violate any draft? I can understand if both options are in there, 
but making my proposal a draft violation seems like a bad idea, as we both 
seem to agree that it's the proper thing to do?

---

From: Shin Miyakawa <[email-masked]>
Date: Tue, 01 Jul 2008 16:46:16 +0900 (JST)

Mikael,

> Well, my personal opinion is that this makes Vista unfit to be a IPv6 CPE. 

fmmm.

> decisions on behalf of Microsoft.

I use that Vista is just as one example.
The Strong Host Model is defined in RFC1122 or STD3. That's a standard.

best wishes,

Shin Miyakawa

---

From: Mikael Abrahamsson <[email-masked]>
Date: Tue, 1 Jul 2008 09:51:53 +0200 (CEST)

On Tue, 1 Jul 2008, Shin Miyakawa wrote:

> I use that Vista is just as one example. The Strong Host Model is 
> defined in RFC1122 or STD3. That's a standard.

But if it's a router (which I think is what is needed for a IPv6 CPE) then 
it should be able to act as one, and use loopback interfaces to source 
traffic.

So if MS is serious about Vista being capable of acting a router/home 
gateway, then they should include capabilties needed for such a device. 
Sourcing traffic from loopback interfaces is important for a router.

---

From: Shin Miyakawa <[email-masked]>
Date: Tue, 01 Jul 2008 17:03:27 +0900 (JST)

Mikael,

Let us forget about how Microsoft is doing :-)

> it should be able to act as one, and use loopback interfaces to source 

Even in this case, some software which is going to send a packet to the network
from CPE, according to RFC3484 "Default Address Selection for IPv6",
there is a certain reason why the WAN I/F's IP address should be used as
its source address like follows.

   ---------------- from RFC3484 ----------------
   It is RECOMMENDED that the candidate source addresses be the set of
   unicast addresses assigned to the interface that will be used to send
   to the destination.  (The "outgoing" interface.)  On routers, the
   candidate set MAY include unicast addresses assigned to any interface
   that forwards packets, subject to the restrictions described below.

      Discussion:  The Neighbor Discovery Redirect mechanism [14]
      requires that routers verify that the source address of a packet
      identifies a neighbor before generating a Redirect, so it is
      advantageous for hosts to choose source addresses assigned to the
      outgoing interface.  Implementations that wish to support the use
      of global source addresses assigned to a loopback interface should
      behave as if the loopback interface originates and forwards the
      packet.
   ---------------- from RFC3484 ----------------

Best wishes,

Shin Miyakawa

---

From: Mikael Abrahamsson <[email-masked]>
Date: Tue, 1 Jul 2008 10:16:45 +0200 (CEST)

>   that forwards packets, subject to the restrictions described below.

What is the reason for this recommendation?

---

From: Shin Miyakawa <[email-masked]>
Date: Tue, 01 Jul 2008 17:26:22 +0900 (JST)

From: Mikael Abrahamsson <[email-masked]>
Subject: Re: new draft on IPv6 CPE router available for review
Date: Tue, 1 Jul 2008 10:16:45 +0200 (CEST)

> What is the reason for this recommendation?

Let's wait for the RFC author's answer :-)

Shin Miyakawa