Re: Alia Atlas' Discuss on draft-ietf-bfd-seamless-ip-04: (with DISCUSS)

[Alia Atlas <[e-mail]>]

LGTM

On Tue, May 3, 2016 at 12:53 PM, Carlos Pignataro (cpignata) <
[e-mail]> wrote:

> Hi, Alia,
>
> Thanks, and sounds good. This is what we have implemented, which should
> address both:
>
> @@ -122,9 +122,9 @@
>     The BFD Echo port defined by [RFC5881], port 3785, is used for the
>     S-BFD Echo function on IPv4, IPv6 and MPLS environments.
>     SBFDInitiator sessions MUST transmit S-BFD echo packets with
> -   destination port 3785.  This document defines only the UDP port value
> -   for the S-BFD Echo function.  The source port and the procedures for
> -   the S-BFD Echo function are outside the scope of this document.
> +   destination port 3785.  The setting of the UDP source port [RFC5881]
> +   and the procedures [I-D.ietf-bfd-seamless-base] for the S-BFD Echo
> +   function are outside the scope of this document.
>
>  4.  S-BFD Control Packet Demultiplexing
>
> @@ -138,13 +138,13 @@
>     S-BFDReflector), then the packet MUST be looked up to locate a
>     corresponding SBFDReflector session based on the value from the "your
>     discriminator" field in the table describing S-BFD discriminators.
> -   If the port is not 7784, then the packet MUST be looked up to locate
> -   a corresponding SBFDInitiator session or classical BFD session based
> -   on the value from the "your discriminator" field in the table
> -   describing BFD discriminators.  If the located session is an
> -   SBFDInitiator, then the destination IP address of the packet SHOULD
> -   be validated to be for self.  If the packet is a classical BFD
> -   session, then the procedures from [RFC5880] apply.
> +   If the port is not 7784, but the packet is demultiplexed to be for an
> +   SBFDInitiator, then the packet MUST be looked up to locate a
> +   corresponding SBFDInitiator session based on the value from the "your
> +   discriminator" field in the table describing BFD discriminators.  In
> +   that case, then the destination IP address of the packet SHOULD be
> +   validated to be for itself.  If the packet demultiplexes to a
> +   classical BFD session, then the procedures from [RFC5880] apply.
>
>  5.  Initiator Procedures
>
> @@ -165,7 +165,7 @@
>
>
> Thanks,
>
> — Carlos.
>
> On May 3, 2016, at 12:30 PM, Alia Atlas <[e-mail]> wrote:
>
> Hi Carlos,
>
> On Mon, May 2, 2016 at 7:22 PM, Carlos Pignataro (cpignata) <
> [e-mail]> wrote:
>
>> Hi Alia,
>>
>> Thanks for the review and for these! Please see inline.
>>
>> > On May 2, 2016, at 6:26 PM, Alia Atlas <[e-mail]> wrote:
>> >
>> > Alia Atlas has entered the following ballot position for
>> > draft-ietf-bfd-seamless-ip-04: Discuss
>> >
>> > When responding, please keep the subject line intact and reply to all
>> > email addresses included in the To and CC lines. (Feel free to cut this
>> > introductory paragraph, however.)
>> >
>> >
>> > Please refer to
>> https://www.ietf.org/iesg/statement/discuss-criteria.html
>> > for more information about IESG DISCUSS and COMMENT positions.
>> >
>> >
>> > The document, along with other ballot positions, can be found here:
>> > https://datatracker.ietf.org/doc/draft-ietf-bfd-seamless-ip/
>> >
>> >
>> >
>> > ----------------------------------------------------------------------
>> > DISCUSS:
>> > ----------------------------------------------------------------------
>> >
>> > I think that these are both simple fast issues to resolve.
>> >
>> > 1) Sec 3: "This document defines only the UDP port value
>> >   for the S-BFD Echo function.  The source port and the procedures for
>> >   the S-BFD Echo function are outside the scope of this document."
>> > Please add a reference to the S-BFD base document for defining where the
>> > procedures are found.
>> >
>> > Where, precisely, is the source port defined?  It wasn't in the S-BFD
>> > base
>> > document.  This seems like a hole.  Can you please clarify?
>>
>> This is done exactly as in RFC 5881, purposefully. I can add a clarifying
>> sentence like:
>>
>> OLD:
>>    This document defines only the UDP port value
>>    for the S-BFD Echo function.  The source port and the procedures for
>>    the S-BFD Echo function are outside the scope of this document.
>>
>> NEW:
>>    S-BFD echo follows the BFD echo definitions of [RFC 5881].
>>    Consequently, this document defines only the UDP port value
>>    for the S-BFD Echo function; the source port and the procedures for
>>    the S-BFD Echo function are outside the scope of this document.
>>
>
> How about a reference by the source port to [RFC 5881] and a reference
> for the procedures for the S-BFD Echo function
> [draft-ietf-bfd-seamless-base]?
>
> What wasn't clear to me - not having recently read RFC 5881 in detail - was
> that the UDP source port was defined in RFC 5881.  I knew the procedures
> were
> in draft-ietf-bfd-seamless-base.
>
>
>> >
>> > 2) Sec 4:  " If the port is not 7784, then the packet MUST be looked up
>> > to locate
>> >   a corresponding SBFDInitiator session or classical BFD session based
>> >   on the value from the "your discriminator" field in the table
>> >   describing BFD discriminators. "
>> >
>> > I assume that you mean that UDP source port is used to look up the
>> > appropriate receiver.
>> > If that receiver handles BFD and S-BFD packets, then the "your
>> > discriminator" field is used
>> > to identify the BFD session.   PLEASE clarify that because this reads as
>> > if BFD is the only
>> > application that uses UDP.
>> >
>>
>> Indeed, very much so. I suggest:
>>
>> OLD:
>>    If the port is not 7784, then the packet MUST be looked up to locate
>>    a corresponding SBFDInitiator session or classical BFD session based
>>    on the value from the "your discriminator" field in the table
>>    describing BFD discriminators.  If the located session is an
>>    SBFDInitiator, then the destination IP address of the packet SHOULD
>>    be validated to be for self.  If the packet is a classical BFD
>>    session, then the procedures from [RFC5880] apply.
>>
>> NEW:
>>    If the port is not 7784, but the packet is demultiplexed to be for an
>>    SBFDInitiator, then the packet MUST be looked up to locate
>>    a corresponding SBFDInitiator session based
>>    on the value from the "your discriminator" field in the table
>>    describing BFD discriminators.  In that case,
>>    then the destination IP address of the packet SHOULD
>>    be validated to be for itself.  If the packet demultiplexes to a
>> classical BFD
>>    session, then the procedures from [RFC5880] apply.
>>
>> Would that work?
>>
>
> Sure - sounds good.  Thanks,
> Alia
>
>
>> Thanks,
>>
>> — Carlos.
>>
>> >
>> >
>> >
>>
>>
>
>