Subject: Re: Last Call: <draft-ietf-intarea-ipv4-id-update-05.txt> (Updated
 Specification of the IPv4 ID Field) to Proposed Standard
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From: Joe Touch <touch@isi.edu>
In-Reply-To: <500654AB.7060500@necom830.hpcl.titech.ac.jp>
Date: Wed, 18 Jul 2012 11:29:55 -0700
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References: <20120531143816.30508.66250.idtracker@ietfa.amsl.com>
 <Pine.LNX.4.64.1205311957420.31608@shell4.bayarea.net>
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 <500654AB.7060500@necom830.hpcl.titech.ac.jp>
To: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
Cc: ietf@ietf.org
Precedence: list

On Jul 17, 2012, at 11:16 PM, Masataka Ohta wrote:

> Joe Touch wrote:
>=20
>>> Or, are 6 to 4 translators are required to rate limit and
>>> drop rate-violating packets to make the "stateless"
>>> translators full of states.
>>=20
>> I would expect that the translator would be responsible
>> for this, though
>=20
> Do you mean translators must rate limit, or translators
> violate RFC2765:

Translators violate RFC791. They cannot merely copy the low-order bits =
of the field, since that is insufficiently unique, and isn't specified =
as being generated at the IPv6 source in compliance with IPv4 =
requirements.

>> there is the problem that multiple translators interfere
>> with each other.
>=20
> Yes, even rate limiting translators may interfere each other,
> which means rate limiting must be done at the IPv6 source
> node.
>=20
>> Regardless, this is outside the scope of the ipv4-id-update doc.
>=20
> In the ID, there are a lot of references to IPv6.

It quotes IPv6 examples, but does not propose to change IPv6 processing. =
That may be needed, but that would be outside the scope of this doc.

> For example, the following statement of the ID:
>=20
>   Finally, the IPv6 ID field is
>   32 bits, and required unique per source/destination address pair for
>   IPv6, whereas for IPv4 it is only 16 bits and required unique per
>   source/destination/protocol triple.
>=20
> must be modified as:
>=20
>   Finally, the IPv6 ID field is
>   32 bits, but lower 16 bits are required unique per
>   source/destination address pair for
>   IPv6,

That's incorrect as per RFC2460. Other RFCs may violate that original =
spec, but that needs to be cleaned up separately.

Joe=