Subject: [BEHAVE] I-D Action:draft-ietf-behave-address-format-01.txt

From: [email-masked]
Date: Mon, 26 Oct 2009 08:45:01 -0700 (PDT)

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Behavior Engineering for Hindrance Avoidance Working Group of the IETF.

	Title           : IPv6 Addressing of IPv4/IPv6 Translators
	Author(s)       : C. Huitema, et al.
	Filename        : draft-ietf-behave-address-format-01.txt
	Pages           : 15
	Date            : 2009-10-26

This document discusses how an individual IPv6 address can be
algorithmically translated to a corresponding IPv4 address, and vice
versa, using only statically configured information.  This technique
is used in IPv4/IPv6 translators, as well as other types of proxies
and gateways (e.g., for DNS) used in IPv4/IPv6 scenarios.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-behave-address-format-01.txt

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

Below is the data which will enable a MIME compliant mail reader
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Internet-Draft.

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From: <[email-masked]>
Date: Mon, 26 Oct 2009 17:56:01 +0100

Hi,
I have some difficulties to understand the figure in chapter 2.
An IPv6 address is only 16 byte long and not 17.
More precisely it is difficult to understand the last line of the figure.
Is it a /96 prefix without byte u or is it a /88 prefix with a u byte ?

Best regards

Eric BURGEY

France TELECOM
Orange Labs

-----Message d'origine-----
De : [email-masked] [mailto:[email-masked]] De la part de [email-masked]
Envoyé : lundi 26 octobre 2009 16:45
À : [email-masked]
Cc : [email-masked]
Objet : [BEHAVE] I-D Action:draft-ietf-behave-address-format-01.txt

---

From: Dave Thaler <[email-masked]>
Date: Mon, 26 Oct 2009 18:35:36 +0000

I agree the figure looks incorrect.
I believe the intent was to look like this:

    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |PLEN| 0-------------32--40--48--56--64--72--80--88--96--104-112-120-|
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/32 |     prefix    |v4(32)         | u | suffix                    |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/40 |     prefix        |v4(24)     | u |(8)| suffix                |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/48 |     prefix            |v4(16) | u | (16)  | suffix            |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/56 |     prefix                |(8)| u |  v4(24)   | suffix        |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/64 |     prefix                    | u |   v4(32)      | suffix    |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/96 |     prefix                                    |   v4(32)      |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+

-Dave

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On
> Behalf Of [email-masked]
> Sent: Monday, October 26, 2009 9:56 AM
> To: [email-masked]
> Subject: Re: [BEHAVE] I-D Action:draft-ietf-behave-address-format-
> 01.txt
> 
> Hi,
> _______________________________________________
> Behave mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/behave

---

From: Dave Thaler <[email-masked]>
Date: Mon, 26 Oct 2009 18:44:05 +0000

I missed answering Eric's second question, about why "u" isn't in the last
line.  I agree it should be.  If the prefix is a well-known /96 prefix,
then the well-known prefix would have the u bits specified correctly by
IANA.  If the prefix is a network-specific prefix, or a shorter well-known 
prefix, then the use of the "u" should be no different from any other line.

-Dave

> Behalf Of Dave Thaler
> Sent: Monday, October 26, 2009 11:36 AM
> To: [email-masked]; [email-masked]
>     |/96 |     prefix                                    |   v4(32)
> |

---

From: Christian Huitema <[email-masked]>
Date: Mon, 26 Oct 2009 19:07:30 +0000

Sorry about the bug in the figure. We will fix that in the next version.

As for the (u) byte being required or not, it depends. The real requirement is that the prefix be compatible with the addressing architecture, i.e.:

   For all unicast addresses, except those that start with the binary
   value 000, Interface IDs are required to be 64 bits long and to be
   constructed in Modified EUI-64 format.

So the requirement is either to use the WKP, or if you use a Network Specific Prefix to have the (u) byte correctly set. The table would become:

    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |PLEN| 0-------------32--40--48--56--64--72--80--88--96--104-112-120-|
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/32 |     prefix    |v4(32)         | u | suffix                    |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/40 |     prefix        |v4(24)     | u |(8)| suffix                |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/48 |     prefix            |v4(16) | u | (16)  | suffix            |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/56 |     prefix                |(8)| u |  v4(24)   | suffix        |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/64 |     prefix                    | u |   v4(32)      | suffix    |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/88 |     prefix (64)               | u |  (24)     |   v4(32)      |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    |/96 |     prefix (compatible with RFC 4291)         |   v4(32)      |
    +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+

Hopefully, by the next edition, we will have a clear idea of what the well known prefix should be, e.g. what value, 32 or 96 bits, etc. That will make diagrams simpler.

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Dave Thaler
Sent: Monday, October 26, 2009 11:44 AM
To: Dave Thaler; [email-masked]; [email-masked]
Subject: Re: [BEHAVE] I-D Action:draft-ietf-behave-address-format-01.txt

-Dave