Re: 6MAN WG Last Call: draft-shore-icmp-aup

[神明達哉 <[e-mail]>]

At Fri, 13 Dec 2013 11:41:05 +0100,
Ole Troan <[e-mail]> wrote:

> Our AD has requested that the 6MAN working group review this document. This is part of our chartered work
> to review documents produced outside of 6MAN, that may extend or change the IPv6 protocol.

[...]

> As with our regular working group last calls, the chairs would like to solicit one or two people in the working group
> to do a detailed review of the document.

I've read the draft.  I don't know if this meets the requirement for a
"detailed review", but here are my comments anyway:

- Overall, I didn't see a critical issue in it.  It's also pretty
  clear and easy to understand.  I can't say anything about the
  importance of the draft, though, simply because I don't know much
  about the background concerns.  I also don't know if the proposed
  guideline and categorization are the "best current practice", but I
  don't have a strong opinion on these anyway.

- In Section 2, I think it'd be more helpful if it shows some examples
  of "other uses":

   Normally, other uses are not advisable.

  Now that I've read the entire draft (Section 2.1.1 and Section 4 in
  particular), I guess the example could be "used as a routing or
  network management protocol".

- The subsequent sentence placed in the same paragraph was confusing
  to me:

   [...]  While ICMP's role is not to
   be a general-purpose network management protocol, it does have a role
   to play in conveying dynamic information about a network.

  in that I couldn't understand the relationship between the first and
  second sentences.  Maybe the example mentioning "network management
  protocol" as suggested in the previous bullet will help clarify
  that.  For example:

   Normally, other uses such as implementing a routing or
   general-purpose network management protocol are not advisable.
   However, it does have a role to play in conveying dynamic
   information about a network, which would belong to category 2
   above.

- In Section 2.3, it states:

   Because ICMPv6 is used for IPv6 Neighbor Discovery, deployed IPv6
   routers, IPv6-capable security gateways, and IPv6-capable firewalls
   normally support administrator configuration of how specific ICMPv6
   message types are handled.

  Is this true?  The question is actually two-fold: I'm not sure if
  it's true that "IPv6-capable firewalls normally support..."
  (especially if such FWs don't have the support for ICMPv4); even if
  this is true, I'm not sure if that's because ICMPv6 is used for ND.
  ND messages are only used in a single link, so at least for
  firewalls from one link to another, ND should still work even if
  they filter any ICMPv6 packets without any configuration knob.  If
  these are really true and the fact, then that's fine.  It just
  didn't seem to me likely.

- A very minor point: I think "sections" should be "section":

   In following sections we provide some background on the differences
   between control and management traffic.
   (last paragraph of Section 3)

  because, if I understand it correctly, this "sections" specifically
  means Section 4 and only that section (and it doesn't have any
  subsections).

--
JINMEI, Tatuya