Re: [v6ops] I-D Action: draft-ietf-v6ops-design-choices-04.txt

Mark ZZZ Smith <> Fri, 20 February 2015 02:50 UTC

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From: Mark ZZZ Smith <>
To: Philip Matthews <>, v6ops list <>
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Subject: Re: [v6ops] I-D Action: draft-ietf-v6ops-design-choices-04.txt
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I'd like to see less implication that the choice between a single ULA and a single global prefix on a link is exclusive e.g.,

"The use of ULAs instead of globally-routed
addresses is also not discussed;"

"b.  Have global (or unique-local) addresses assigned in addition to

People really need to get over this (somewhat IPv4) idea that there can only be one prefix on a link (of course, in IPv6 there are always link-locals too, but the limit on link prefixes isn't two either.).

"Proper" support for multiple prefixes on a link is one of IPv6's enhanced capabilities over IPv4's. People should be encouraged to take advantage of it if it would be useful to them.


----- Original Message -----
From: Philip Matthews <>
To: v6ops list <>
Sent: Thursday, 19 February 2015, 8:23
Subject: Re: [v6ops] I-D Action: draft-ietf-v6ops-design-choices-04.txt

Hi Everyone:

Victor and I just posted this update, which addresses the comments raised in Honolulu, and generally cleans up the draft. No really big changes, but lots of little changes.  

A few highlights:
* The wording in the title, abstract and introduction has been modified to narrow the scope of the document. The document no longer claims to cover all choices around designing IPv6 network, but just certain choices that are routing-related. This always been the de-facto situation, but now the introduction etc reflect this.  Some additional sentences saying "X is not covered here, see doc Y" have also been added. Thanks to Dave Thaler and Eric Vyncke for suggestions in this area.
* The text around using BGP sessions to link-local addresses has been updated after some email exchanges with Francis Dupont (co-author of RFC 2545), who observed that RFC 2545 forbids this (even though most vendors support it).
* The text around security of link-local addresses has been modified since some routers forward packets containing link-local source addresses. Thanks to Jen Lincova for pointing this out.
* The initial few sentences in a number of sections has been changed in an attempt to improve the document flow.
* The document now has a security considerations section. There is nothing earth-shaking here; Victor and I elected to just point to some existing documents that are relevant to the choices discussed in the document.

There were many other small changes to try to improve document wording and clarity, and I thank a number of my colleagues at Alcatel-Lucent for their helpful reviews.

Overall, Victor and I feel this new version is much improved, and we hope you guys will too. As always, we welcome further comments.

- Philip

On 2015-02-18, at 15:57 , wrote:

> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> This draft is a work item of the IPv6 Operations Working Group of the IETF.
>        Title           : Some Design Choices for IPv6 Networks
>        Authors         : Philip Matthews
>                          Victor Kuarsingh
>     Filename        : draft-ietf-v6ops-design-choices-04.txt
>     Pages           : 17
>     Date            : 2015-02-18
> Abstract:
>   This document presents advice on certain routing-related design
>   choices that arise when designing IPv6 networks (both dual-stack and
>   IPv6-only).  The intended audience is someone designing an IPv6
>   network who is knowledgeable about best current practices around IPv4
>   network design, and wishes to learn the corresponding practices for
>   IPv6.
> The IETF datatracker status page for this draft is:
> There's also a htmlized version available at:
> A diff from the previous version is available at:
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at
> Internet-Drafts are also available by anonymous FTP at:
> _______________________________________________
> v6ops mailing list


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