Hi John,
Thank you for the review and thoughtful comments.
Please see inline.
Original
From: JohnScudderviaDatatracker <nore...@ietf.org>
To: The IESG <i...@ietf.org>;
Cc: draft-ietf-nvo3-bfd-gen...@ietf.org
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Date: 2023年08月04日 03:40
Subject: John Scudder's Discuss on draft-ietf-nvo3-bfd-geneve-12: (with DISCUSS
and COMMENT)
John Scudder has entered the following ballot position for
draft-ietf-nvo3-bfd-geneve-12: Discuss
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DISCUSS:
----------------------------------------------------------------------
Thanks for this valuable and easy-to-read spec. I have one concern that I'd
like to have a discussion about; I hope this will be easy to resolve.
[XM]>>> I believe so. :-)
There are several places where you use MUST in a way I think is unnecessary,
you seem to be saying, in effect, "to do Geneve you MUST do Geneve". Most of
these are harmless IMO (I put some examples in the COMMENT section just in case
you're unclear what I'm talking about) but there are two that seem problematic
to me, nearly-identical sentences from Sections 4.1 and 5.1:
Then the Destination IP, the UDP destination port and
the TTL or Hop Limit of the inner IP packet MUST be validated to
determine whether the received packet can be processed by BFD.
and
Then the UDP destination port and the TTL or Hop Limit
of the inner IP packet MUST be validated to determine whether the
received packet can be processed by BFD.
In both cases, it's unclear to me if you're just saying "Geneve has certain
validation rules that have to be met before the packet can be passed to the
upper layer", or if you're introducing a new requirement. In the former case,
please be more transparent about that, possibly with a citation to the
validation rules in the underlying spec. You could also consider dropping the
RFC 2119 MUST. In the latter case, if you're truly introducing a new
requirement, I think the validation rules need to be spelled out much more
clearly. (I think it's probably the former case.)
[XM]>>> It seems a mix of the two cases, and for the former case the
underlying spec is RFC 5881.
Propose to change the text as below.
OLD
Then the Destination IP, the UDP destination port and the
TTL or Hop Limit of the inner IP packet MUST be validated to determine
whether the received packet can be processed by BFD.and Then
the UDP destination port and the TTL or Hop Limit of the inner IP packet MUST
be validated to determine whether the received packet can be processed by BFD.
NEW
Then the Destination IP, the UDP destination port and the
TTL or Hop Limit of the inner IP packet MUST be validated to determine
whether the received packet can be processed by BFD, i.e., the three field
values of the inner IP packet MUST be in compliance
with what's defined in Section 4.
and Then the UDP destination port and the TTL or Hop Limit
of the inner IP packet MUST be validated to determine whether the received
packet can be processed by BFD, i.e., the two field values of the
inner IP packet MUST be in compliance with what's defined in Section 5.
----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------
- Please consider expanding "FCS" where used, or glossing it elsewhere.
[XM]>>> OK. Will add "FCS" to the Abbreviations section.
- This sentence in Sections 4.1 and 5.1,
The Destination MAC of the inner Ethernet
frame matches the MAC address of a VAP which is mapped to the same as
received VNI.
has a grammatical problem that prevents me from making sense of it. I *think*
you are missing a noun after "the same", so it should be something like "The
Destination MAC _address_ of the inner Ethernet frame matches the MAC address
of a VAP which is mapped to the same _???_ as _the_ received VNI."
Or maybe some other rewrite is needed, but anyway, it's not clear as it stands.
[XM]>>> Propose to change this sentence as below.
OLD
The Destination MAC of the inner Ethernet frame
matches the MAC address of a VAP which is mapped to the same as received VNI.
NEW
The Destination MAC address of the inner Ethernet
frame matches the MAC address of a VAP which is mapped to the same VNI as the
received VNI.
- Here are a few examples where I think you have MUSTs that may be unnecessary,
as referenced in my DISCUSS. I don't insist on any changes related to these,
I'm just providing them for your information.
The Outer
IP/UDP and Geneve headers MUST be encoded by the sender as defined in
[RFC8926].
("MUST be" could be "are"; occurs 2x in the doc)
[XM]>>> Will do s/MUST be/are.
Opt Len field MUST be set consistent with the Geneve specification
(This could be "The usage of the Opt Len field is specified in [RFC8926], and
depends on whether or not", etc; occurs 2x in the doc)
[XM]>>> In this case I prefer to remain it as is, because MUST/SHOULD is also
used for other fields of the Geneve header.
Once a packet is received, the NVE MUST validate the packet as
described in [RFC8926].
(Could be "... the NVE validates..."; occurs 2x in the doc)
[XM]>>> Will do s/MUST validate/validates.
Best Regards,
Xiao Min_______________________________________________
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