Fw: 6MAN WG Last Call: draft-ietf-6man-uri-zoneid-00.txt

From: t.petch <ietfa@btconnect.com> · Date: Tue, 6 Mar 2012 16:38:06 +0100

For those with an interest in the ABNFing of URI who have not seen this on the
IETF uri-review or on ipv6 lists, the question is how to tack an ipv6 zoneid
onto the constructs in RFC3986, while preserving the long standing ipv6 practice
of using a percent character as the separator in this case.

I would suggest follow-up on one of the two afore mentioned lists.

Tom Petch

----- Original Message -----
From: "Bill Fenner" <fenner@fenron.net>
To: "Brian E Carpenter" <brian.e.carpenter@gmail.com>
Cc: <ipv6@ietf.org>; "Brian Haberman" <brian@innovationslab.net>; "S Moonesamy"
<sm+ietf@elandsys.com>; <ipv6-chairs@tools.ietf.org>
Sent: Tuesday, March 06, 2012 1:08 PM
Subject: Re: 6MAN WG Last Call: draft-ietf-6man-uri-zoneid-00.txt

On Mon, Mar 5, 2012 at 7:15 PM, Brian E Carpenter
<brian.e.carpenter@gmail.com> wrote:
> Carsten,
>
> On 2012-03-06 12:22, Carsten Bormann wrote:
>> On Mar 6, 2012, at 00:00, Brian E Carpenter wrote:
>>
>>> No, I think it's exactly *not* confused on this point. There's
>>> a distinction between the idealised URI and the produced URI;
>>> in the produced URI, "%25" stands for "%" in the idealised URI.
>>
>> Ah, so the ABNF is wrong
>
> I don't believe so. The ABNF does not describe the produced (encoded)
> URI. I have read sections 2.2 and 2.4 of RFC 3986 several times
> before asserting this. Of course I could be wrong, but we are waiting
> for a review from uri-review@ietf.org who will hopefully give a
> definitive answer.
>
>> and the (vague) text is meant as I read it first (it can be read in other
ways).
>
> Please indicate exactly which part of the text is ambiguous, and we'll
> change it.
>
>>
>> Replace
>>
>> IPv6addrz = IPv6address [ "%" ZoneID ]
>>
>> by
>>
>> IPv6addrz = IPv6address [ "%25" ZoneID ]
>
> No. In the encoded URI that would end up as %2525. That's exactly the
> trap that RFC 3986 warns against.
>
>>
>>
>>> We have no real choice but to use % since that was chosen years
>>> ago, and that means that the produced URI contains %25.
>>
>> I don't know that. You could use "percent" and that would work, too.
>
> We could use any unreserved symbol, but that would need translation from
> the RFC 4007 format. For example we could just use Z, as in
> http://[fe80::aZen1].
> Or we could use ~: http://[fe80::a~en1].
>
> Would that be less confusing?

Previous joint work between the ipv6 working group and the W3C URI
working group resulted in a decision that did not change the ABNF at
all, in 2 ways:

1. It used the IPvFuture extension mechanism;
2. It used a non-percent character for the separator.

At the time, the URI working group was very concerned about the change
in the ABNF and the use of percent where percent had not previously
been allowed.  Have they changed their position here, or have they not
had a chance to comment on this change yet?

This work was accepted as an ipv6 wg work item around IETF63 (Paris,
2005), but the authors never pushed the document forward due to a lack
of interest in the broader community.  The draft that was adopted by
the wg was

http://tools.ietf.org/html/draft-fenner-literal-zone-01

  Bill
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