Re: [Lsr] Benjamin Kaduk's No Objection on draft-ietf-ospf-ospfv2-hbit-11: (with COMMENT)

[Padma Pillay-Esnault <[e-mail]>]

Hi Ben

Thanks for your thorough review.

See below PPE for my comments

On Tue, Dec 3, 2019 at 5:45 PM Benjamin Kaduk via Datatracker <
[e-mail]> wrote:

> Benjamin Kaduk has entered the following ballot position for
> draft-ietf-ospf-ospfv2-hbit-11: No Objection
>
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> The document, along with other ballot positions, can be found here:
> https://datatracker.ietf.org/doc/draft-ietf-ospf-ospfv2-hbit/
>
>
>
> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
>
> Abstract
>
>    The Open Shortest Path First Version 2 (OSPFv2) does not have a
>    mechanism for a node to repel transit traffic if it is on the
>    shortest path.  This document defines a bit (Host-bit) that enables a
>
> nit: I suggest to add "protocol" after "(OSPFv2)" to match the definite
> article "The".
>
> PPE - ok


> Section 1
>
>    The OSPFv2 specifies a Shortest Path First (SPF) algorithm that
>
> (same nit about adding "protocol")
>
> PPE - ok


>    This functionality is particularly useful for a number of use cases:
>
> nit: "this functionality" seems to refer to "the SPF algorithm that
> identifies transit verticies based on their adjacencies", so I suggest
> rewording to "such functionality would be useful" or "A mechanism to
> move traffic away from the shortest path" or similar.
>
> PPE - ok will change as you suggest

Suggested NEW:
"A mechanism to move traffic away from the shortest path is particularly
useful for a number of use cases:"


> Section 4
>
> I suggest noting that the (lettered) sub-procedures of step (2) remain
> unchanged.
>
> PPE - The original format of OSPF rfc2328 steps for SPF calculation was
kept for clarity. Would a sentence to that effect work?



> Section 5
>
>    In normal operation, there is no guarantee that the RI LSA will reach
>    all routers in an area in a timely manner, which may result in
>    forwarding loops in partial deployments.  For example, if a new
>    router joins an area, which previously had only H-bit capable routers
>    with H-bit set then it may take some time for the RI to propagate to
>    all routers.
>
> It's currently only implicit that this new router does not support the
> H-bit; shall we make it explicit?
>

PPE - ok

Suggested NEW:
 If a new router without H-bit support joins an area, which previously had
only H-bit capable routers
 with H-bit set then it may take some time for the RI to propagate to all
routers.



>    o  All routers supporting H-Bit MUST check all the RI LSAs of nodes
>       in the area before actively running the modified SPF to account
>       for the H-bit in order to verify that all routers are in routing
>       capability.  If any router does not advertise the Host Router
>
> nit: the grammar here is a little wonky, particularly for "all routers
> are in routing capability" but perhaps also for "to account for the
> H-bit".
>
> PPE -  agree

Suggested NEW:
All routers supporting H-Bit MUST check all the RI LSAs of nodes in the
area before actively
running the modified SPF in order to verify that all routers in the area
support the H-bit capability.


Section 6
>
>    When calculating the path to an OSPF AS-External-LSA or NSSA-LSA
>    [RFC3101] with a Type-2 metric, [...]
>
> nit: is this saying "calculating the path to [an LSA]"?  That's not a
> usage I'm familiar with; can the AS-External-LSA or NSSA-LSA really
> serve as a destination in this sense?
>
> PPE - suggest adding the word " prefix" which was implicit here.


> Section 7
>
> Thank you for phrasing this as "this document requests the IANA to
> assign", since until these specific values are officially assigned we
> are technically "squatting" on them.  (The respective registration
> policies of Standards Action and IETF Review give us pretty good control
> that nothing else is going to swoop in on them, though.)
>
>
>
Let me know if these changes address your comments

Padma