Subject: [RTG-DIR] RtgDir review: draft-ietf-ospf-ospfv3-autoconfig-09

From: Martin Vigoureux <[email-masked]>
Date: Mon, 5 Jan 2015 13:07:08 +0100

Hello,

I have been selected as the Routing Directorate reviewer for this draft. 
The Routing Directorate seeks to review all routing or routing-related 
drafts as they pass through IETF last call and IESG review, and 
sometimes on special request. The purpose of the review is to provide 
assistance to the Routing ADs. For more information about the Routing 
Directorate, please see ​ 
http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir

Although these comments are primarily for the use of the Routing ADs, it 
would be helpful if you could consider them along with any other IETF 
Last Call comments that you receive, and strive to resolve them through 
discussion or by updating the draft.

Document: draft-ietf-ospf-ospfv3-autoconfig-09
Reviewer: Martin Vigoureux
Review Date: 2015-01-05
IETF LC End Date: n/a
Intended Status: Proposed Standard

Summary:
This Document is ready for publication. It has one or two typos.
I have a couple of questions (see Minor Issues).

Comments:
This Document is well written and provides the necessary information and 
context for readers to understand what it specifies.

Minor issues:
    As OSPFv3 Router implementing this specification must select a unique

Is that a must or a MUST? I guess it is a must since it is said 
afterwards that the uniqueness is not 100% guaranteed, but I just wanted 
to make sure.
Yet, since there is a possibility of a Router ID collision, couldn't the 
sentence be rephrased as follows to reflect the reality:
    An OSPFv3 Router implementing this specification must ideally select
    a unique Router ID.

    An OSPFv3 router implementing this specification MUST compare a
    received self-originated Auto-Configuration LSA's Router-Hardware
    Fingerprint TLV against its own router hardware fingerprint. If the
    fingerprints are not equal, there is a duplicate Router ID conflict
    and the OSPFv3 Router with the numerically smaller router hardware
    fingerprint MUST select a new Router ID as described in Section 7.3.

I feel that these two sentences are not crystal clear. Forgive me if it 
is only due to me not being a native English reader.
The second sentence implies that fingerprints between "a received 
self-originated" LSA and a router's own hw fingerprint can be different.
In the first sentence, I read "self" as referring to the router which is 
the subject of that sentence, and I therefore fail to understand how an 
LSA originated by a router could arrive back to that router but with a 
different fingerprint.
Also, the second sentence seems to imply that iff fingerprints are 
different then the Router IDs are the same. I know that we are in a 
section about Duplicate Router ID, but just as for Section 7.1 which 
clearly sets the conditions, it might be worth saying that if 
fingerprints are different and OSPFv3 Router IDs identical then there is 
a duplicate Router ID conflict. But again, this might not be needed if 
my reading of *self* is wrong.

Nits:
    OSPFv3 SHOULD be auto-configured on for IPv6 on all interfaces
Isn't "on" after "auto-configured" superfluous?

s/As OSPFv3 Router implementing/An OSPFv3 Router implementing/

The document uses both "OSPFv3 Router" and "OSPFv3 router".
It may be worth using only one way of writing it.

Thanks

Martin,
wishing you all the best for 2015

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From: "Acee Lindem (acee)" <[email-masked]>
Date: Mon, 5 Jan 2015 17:32:08 +0000

Hi Martin, 

>    An OSPFv3 Router implementing this specification must ideally select

Ultimately, an OSPFv3 router MUST have a unique OSPFv3 Router-ID (although
this may require multiple attempts at selection). How about this?

    An OSPFv3 router requires a unique Router-ID for correct protocol
operation. An OSPFv3 router implementing this specification will select an
initial Router-ID with a high probability of uniqueness. ….

>my reading of *self* is wrong.

I agree that this is not clear since it relies on one deducing that an LSA
is perceived as self-originated if it has the same Router ID. How about
this: 

An OSPFv3 router implementing this specification MUST detect received
Auto-Configuration LSAs with its Router ID specified in the LSA header.
LSAs received with the local OSPFv3 Router's Router ID in the LSA header
are perceived as self-originated (see section 4.6 of [OSPFV3]).  In these
received Auto-Configuration LSAs, the Router-Hardware-Fingerprint TLV is
compared against the OSPFv3 Router's own router hardware fingerprint.  If
the fingerprints are not equal, there is a duplicate Router ID conflict
and the OSPFv3 router with the numerically smaller router hardware
fingerprint MUST select a new Router ID as described in Section 7.3.

>Isn't "on" after "auto-configured" superfluous?

Fixed. 

>s/As OSPFv3 Router implementing/An OSPFv3 Router implementing/

Fixed. 

>It may be worth using only one way of writing it.

These should be "OSPFv3 router”

Thanks,
Acee

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From: Martin Vigoureux <[email-masked]>
Date: Tue, 6 Jan 2015 15:20:13 +0100

Hi Acee

I am fine with the text you propose.
Many thanks

-m