Subject: Re: [homenet] I-D Action: draft-howard-homenet-routing-requirements-00.txt

From: Brian E Carpenter <[email-masked]>
Date: Tue, 03 Jan 2012 10:08:06 +1300

Hi,

>          It may be assumed that each upstream will be connected via a
>          separate router, not multihomed off the same router.

This seems to asume that one router equals one access network equals one
provider. I don't think that's valid as a long term assumption. Any
combination might arise - several upstreams via one router, different
routers for different upstreams, and some upstreams via more than one
router. In fact,

>       A host with mutliple upstream paths to the same destination (in-
>       home or external) should be able to use another in case on fails.

seems to contradict the assumption. Or it's about multi-prefix based
multihoming, which is a different problem altogether (see shim6 or
draft-ietf-v6ops-ipv6-multihoming-without-ipv6nat).

>          Must support a "walled-garden" network.  This might routing
>          based on either source address (from the walled garden network)
>          or destination address (to the walled garden network); support
>          for both is not required.

I thought that the IETF was about the Internet, so we shouldn't be
assisting the creation of walled gardens. However, source-address-based
selection of the next hop is needed anyway, to support multihoming
and deal with ingress filtering. I don't see how any scenario can
avoid destination-address-based routing, so I think that support for
both *is* required.

Regards
   Brian Carpenter

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From: Michael Richardson <[email-masked]>
Date: Mon, 02 Jan 2012 22:00:41 -0500

>>>>> "Brian" == Brian E Carpenter <Brian> writes:
    >> Must support a "walled-garden" network.  This might routing based
    >> on either source address (from the walled garden network) or
    >> destination address (to the walled garden network); support for
    >> both is not required.

    Brian> I thought that the IETF was about the Internet, so we
    Brian> shouldn't be assisting the creation of walled
    Brian> gardens. However, source-address-based selection of the next

No, the IETF is about commuication using the internet (suite of) protocols.
The Internet is just the biggest garden out there. 

Not supporting walled gardens (which are globally uniquely numbered, but
not globally reachable) leads to NAT66 at the border gateways.

(And, we still don't seem to accept packets from Mars.  All sorts of
advice about doing Martian filtering...)

-- 
]       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[
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---

From: Brian E Carpenter <[email-masked]>
Date: Wed, 04 Jan 2012 09:30:13 +1300

> No, the IETF is about commuication using the internet (suite of) protocols.

RFC 3935 says otherwise.

> not globally reachable) leads to NAT66 at the border gateways.

It leads to RFC 4864 actually, which some people objected to violently
for exactly that reason.

> advice about doing Martian filtering...)

Right, but those packets aren't exactly in the spirit of RFC 3935 either.

In any case - my point was that we don't need to make statements about
walled gardens in order to derive the need for source-based routing
decisions. We need that anyway, for multihoming-without-ipv6nat.

   Brian

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From: Michael Richardson <[email-masked]>
Date: Tue, 03 Jan 2012 16:10:58 -0500

>>>>> "Brian" == Brian E Carpenter <Brian> writes:
    Brian> In any case - my point was that we don't need to make
    Brian> statements about walled gardens in order to derive the need
    Brian> for source-based routing decisions. We need that anyway, for
    Brian> multihoming-without-ipv6nat.

okay, I was concerned that you were arguing against source-based routing
decisions.   I personally think that GUA numbered walled gardens are so
incredibly better than NAT(XYZ) that it's close to a killer app for
IPv6.