Subject: Fwd: Last Call: <draft-ietf-opsec-lla-only-07.txt> (Using Only Link-Local Addressing Inside an IPv6 Network) to Informational RFC

From: Brian Haberman <[email-masked]>
Date: Tue, 25 Mar 2014 08:44:39 -0400

All,
     The IETF Last Call just started on this document.  Please review
and comment.

Regards,
Brian

-------- Original Message --------
Subject: Last Call: <draft-ietf-opsec-lla-only-07.txt> (Using Only
Link-Local Addressing Inside an IPv6 Network) to Informational RFC
Date: Mon, 24 Mar 2014 08:51:35 -0700
From: The IESG <[email-masked]>
To: IETF-Announce <[email-masked]>
CC: [email-masked]

The IESG has received a request from the Operational Security
Capabilities for IP Network Infrastructure WG (opsec) to consider the
following document:
- 'Using Only Link-Local Addressing Inside an IPv6 Network'
  <draft-ietf-opsec-lla-only-07.txt> as Informational RFC

The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
[email-masked] mailing lists by 2014-04-07. Exceptionally, comments may be
sent to [email-masked] instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.

Abstract

   In an IPv6 network it is possible to use only link-local addresses on
   infrastructure links between routers.  This document discusses the
   advantages and disadvantages of this approach to help the decision
   process for a given network.

The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-opsec-lla-only/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-opsec-lla-only/ballot/

No IPR declarations have been submitted directly on this I-D.

---

From: 神明達哉 <[email-masked]>
Date: Tue, 25 Mar 2014 09:21:55 -0700

At Tue, 25 Mar 2014 08:44:39 -0400,

>      The IETF Last Call just started on this document.  Please review

I don't subscribe to the opsec ML so I'm only responding here.

I have one small comment: I think this sentence of Section 2.3 needs
some more clarification/correction:

   However, this
   static LLA configuration may be more complex to operate than
   statically configured greater than link-local addresses, because the
   link scope must also be considered, as in this example: 'BGP neighbor
   fe80::1%eth0 is down'.

- First off, it's not clear what "the link scope must also be
  considered" means.  With the example of fe80::1%eth0, I guess it
  tries to talk about the ambiguity of LLAs.  But, in principle, such
  ambiguity is not specific to statically configured LLAs.  So I also
  guess it's also based on the implicit assumption that statically
  configured interface id (such as "::1") tends to be less unique than
  EUI-64 based IIDs, thus tends to be more ambiguous in practice.  If
  this is what this sentence tries to say, I agree, but one would need
  quite a lot of speculation to reach this understanding.
- On the other hand, if this sentence tries to say something
  different, then I didn't get it, so (assuming I'm not the only one)
  it would need clarification anyway:-)
- assuming my guess in the first bullet is correct, "the link scope"
  in this context is not really the accurate term per RFC 4007.  This
  should be "the link (zone) index" ("scope" means a type of scope,
  such as "link" or "site").  I'd also suggest adding a reference to
  the RFC, since the reader may not be familiar with the '%eth0'
  notation.

Combining these, I'd suggest (based on my guessed understanding)
revising the sentence as follows:

   However, this
   static LLA configuration may be more complex to operate than
   statically configured greater than link-local addresses, because
   LLAs are inherently ambiguous for a multi-link node such as a
   router and tend to be more so when the interface ID is configured
   statically.  To deal with the ambiguity, the link zone index must
   also be considered explicitly, e.g., using the extended textual
   notation described in [RFC4007] as in this example: 'BGP neighbor
   fe80::1%eth0 is down'.

--
JINMEI, Tatuya