Re: [RTG-DIR] [Lsr] RtgDir review: draft-ietf-ospf-ospfv3-segment-routing-extensions-17.txt

Erik Auerswald <auerswald@fg-networking.de> Wed, 14 November 2018 13:24 UTC

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Date: Wed, 14 Nov 2018 14:24:16 +0100
From: Erik Auerswald <auerswald@fg-networking.de>
To: Peter Psenak <ppsenak@cisco.com>
Cc: Tomonori Takeda <takeda.tomonori@lab.ntt.co.jp>, rtg-ads@ietf.org, rtg-dir@ietf.org, draft-ietf-ospf-ospfv3-segment-routing-extensions.all@ietf.org, lsr@ietf.org
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References: <42c3e097-9789-49d4-cf15-c3713f4a1c0b@lab.ntt.co.jp> <5BEC1F81.9080103@cisco.com>
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Subject: Re: [RTG-DIR] [Lsr] RtgDir review: draft-ietf-ospf-ospfv3-segment-routing-extensions-17.txt
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Hi Peter,

please see inline (I have kept just the relevant part):

On Wed, Nov 14, 2018 at 02:13:37PM +0100, Peter Psenak wrote:
> On 14/11/18 12:49 , Tomonori Takeda wrote:
> > [...]
> > 1) Flooding Scope of SR-Algorithm TLV
> > In Section 4.1, it says:
> > 
> >    "If the SR-Algorithm TLV appears in
> >     multiple OSPFv3 Router Information Opaque LSAs that have different
> >     flooding scopes, the SR-Algorithm TLV in the OSPFv3 Router
> >     Information Opaque LSA with the area-scoped flooding scope MUST be
> >     used."
> > 
> > At the same time, it say:
> > 
> >    "For the purpose of SR-Algorithm TLV advertisement, area-
> >     scoped flooding is REQUIRED."
> > 
> > So, does it mean a) a router MUST use area-scoped flooding for sending,
> > and
> 
> no. It says that that for the purpose of the SR-Algorithm TLV area scope is
> required. That means it cannot be link-scope, but it can be
> autonomous-system scope, because that is also covering the area-scope.

May I suggest to add the words "at least" to make the wording more
explicit?

    "For the purpose of SR-Algorithm TLV advertisement, at least
     area-scoped flooding is REQUIRED."

Thanks,
Erik