Subject: [OPSEC] Barry Leiba's No Objection on draft-ietf-opsec-ipv6-host-scanning-07: (with COMMENT)

From: "Barry Leiba" <[email-masked]>
Date: Fri, 14 Aug 2015 10:14:28 -0700

Barry Leiba has entered the following ballot position for
draft-ietf-opsec-ipv6-host-scanning-07: No Objection

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COMMENT:
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Nice document you have here.  Just two really small comments, neither of
which needs any response, and both of which you can ignore if you
prefer.

An observation: Three times, you say that something is "obvious", and
this can come across as condescending -- and can be frustrating to a
reader for whom it isn't obvious.  I suggest omitting that, so 

- In Section 3.1.1.1, change "Firstly, as it should be obvious from the
algorithm described above" to "Firstly, as shown by the algorithm
described above".

- In Section 3.1.3.2, change "For obvious reasons, the search space for
addresses following" to "The search space for addresses following".

- In Section 3.3, change "Obviously, a number of other network
reconnaissance vectors" to "A number of other network reconnaissance
vectors".

-- Section 3.1.1.1 --

An observation, for which the response is probably "everyone knows this,
so no change is needed," but please think about it for a fleeting
moment:

   1.  The "Universal" bit (bit 6, from left to right) of the address is
       set to 1

Bit 6, starting from 0, or from 1?  The answer (which I can see from the
example) is "starting from 0."

   Firstly, as it should be obvious from the algorithm described above,
   two bytes (bytes 4-5) of the resulting address always have a fixed
   value (0xff, 0xfe)

Bytes 4-5, starting from 0 or from 1?  The answer (which I can see from
the example) is "starting from 1."

The fact that the origins differ makes me think that it'd be nice if that
were made clear.  Please give it a thought, to say that bits are numbered
from left to right starting at 0, and bytes are numbered from left to
right starting at 1.

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From: Fernando Gont <[email-masked]>
Date: Wed, 19 Aug 2015 02:05:46 +0200

Hi, Barry,

Thanks so much for your feedback! Please find my comment in-line...

Will update. Thanks!

> example) is "starting from 0."

Yes, we assume this to be known.

> the example) is "starting from 1."

Good grief! mm.. how about changing this to "bytes 3-4" -- and also
adding a note regarding how the bytes are numbered?

Thanks!

Best regards,
-- 
Fernando Gont
SI6 Networks
e-mail: [email-masked]
PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492