Re: [trill] Alvaro Retana's No Objection on draft-ietf-trill-p2mp-bfd-08: (with COMMENT)

"Susan Hares" <> Tue, 23 January 2018 22:40 UTC

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From: "Susan Hares" <>
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Date: Tue, 23 Jan 2018 17:40:02 -0500
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Subject: Re: [trill] Alvaro Retana's No Objection on draft-ietf-trill-p2mp-bfd-08: (with COMMENT)
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Thank you for the feedback. 
Sue Hares

-----Original Message-----
From: Alvaro Retana [] 
Sent: Tuesday, January 23, 2018 10:46 AM
To: The IESG
Cc:; Susan Hares;;
Subject: Alvaro Retana's No Objection on draft-ietf-trill-p2mp-bfd-08: (with COMMENT)

Alvaro Retana has entered the following ballot position for
draft-ietf-trill-p2mp-bfd-08: No Objection

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for more information about IESG DISCUSS and COMMENT positions.

The document, along with other ballot positions, can be found here:


(1) The first reference to I-D.ietf-bfd-multipoint appears in Section 5; please add one in the Introduction when Multipoint BFD is initially mentioned.

(2) I think that using Normative Language (without quotation marks) to mention what is specified somewhere else can result in confusion as to which is the authoritative document.  This seems to be the case in Section 4: "If the M bit of the TRILL Header of the RBridge channel packet containing a BFD Control packet is non-zero, the packet MUST be dropped [RFC7175]."  The sentence sounds as if the behavior is specified in rfc7175, but that document says (in Section
3.2 (BFD Control Frame Processing)): "The following tests SHOULD be performed...Is the M bit in the TRILL Header non-zero?  If so, discard the frame."  Note that the behavior specified in rfc7175 doesn't use a "MUST".  The text in this document seems to be used to explain why a new message is needed, and not in a Normative way -- please clarify the text so that there is no inconsistency with respect to rfc7175.

(3) Section 5 says that the "processing in Section 3.2 of [RFC7175] applies...If the M bit is zero, the packet is discarded."  Section 3.2 has that "SHOULD" that I mentioned above, and it also mentions potential security issues, which are not referenced in this document.  Are there reasons to keep the "SHOULD" and not use "MUST" instead (for the p2mp case)?  If the same semantics as in rfc7175 are kept, then the Security Considerations should include the concerns.