Re: 6MAN WG Last Call - draft-ietf-6man-multi-homed-host-03.txt

[神明達哉 <[e-mail]>]

At Wed, 3 Feb 2016 14:28:07 -0800,
Bob Hinden <[e-mail]> wrote:

> This message starts a two week 6MAN Working Group Last Call on advancing:
>
>        Title           : Routing packets from hosts in a multi-prefix network
>        Authors         : Fred Baker
>                          Brian Carpenter
>        Filename        : draft-ietf-6man-multi-homed-host-03.txt
>        Pages           : 13
>        Date            : 2015-12-16
>
>    https://tools.ietf.org/html/draft-ietf-6man-multi-homed-host-03
>
> as a Proposed Standard.  Substantive comments and statements of
> support for publishing this document should be directed to the
> mailing list.  Editorial suggestions can be sent to the authors.
> This last call will end on 17 February 2016.

I think this version is basically good enough for publication.

I have some comments on the latest version.  I don't think they are
blocking issues but may be better addressed before sending it to the
IESG.

- Some of my previous comments seem to be still open.  Although I
  already stated I wouldn't insist, it's not clear whether they were
  rejected as a result or just overlooked, so I'm re-raising them
  here: https://mailarchive.ietf.org/arch/msg/ipv6/42QPrrvdShflkz06tn3vdw33iEo
  The seeming open points are:
  + whether to move the host-model discussion to an appendix
  + about the term "addressless"

- Section 3.1

   As described in [RFC4191] and [RFC4861], a Router Advertisement may
   contain zero or more Prefix information Options (PIOs), zero or more
   Route Information Options (RIOs), or a Default Router List.

  I'm not sure if I can understand the "or a Default Router List"
  part.  If it means 'Router Advertisement may contain...a Default
  Router List', it doesn't make sense since an RA (or any of its
  options) doesn't contain such a list (Default Router List is
  something that a host maintains based on the content of RA).

- Section 3.1: likewise, the use of 'a default router list' in the
  following sentence is confusing, too:

   [...]  In a multi-
   homed network implementing source/destination routing, the
   interpretation of a default router list or an RIO has to be modified
   with the words "if the source address is in one of the prefixes I
   advertise in a PIO".

- Section 3.1

   Bob's first hop routers are Bob-A (to upstream ISP A advertising
   prefix A') and Bob-B (to upstream network B and advertising prefix
   B').

  I'd suggest something like PA and PB instead of A' and B'.  It may
  be a matter of taste, but to me X and X' refer to different
  instances of the same kind of concept (like both are addresses or
  both are prefixes), so the current notation is confusing.

- Section 3.4

   There is potential for adverse interaction with any off-link Redirect
   (Redirect for a GUA destination that is not on-link) message sent by

  Is there any particular intent about why we specially say "GUA" here
  instead of, e.g., just "a global destination"?  For example, does it
  intend to exclude ULAs?  If so, why?  In case of ULAs, while the
  proposed host behavior may be less critical with ULAs in practice, I
  don't see any technical reason why we can't use it for ULAs.

--
JINMEI, Tatuya