Re: WGLC for draft-ietf-bfd-unaffiliated-echo (ending 7 April, 2023)

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Dear Greg,






Thanks for sharing your thoughts, even if they're concerns.


Please see inline...



Original



From: GregMirsky <[e-mail]>
To: Jeffrey Haas <[e-mail]>;
Cc: [e-mail] <[e-mail]>;
Date: 2023年03月27日 13:40
Subject: Re: WGLC for draft-ietf-bfd-unaffiliated-echo (ending 7 April, 2023)



Dear Authors,I read the latest version of the draft. I appreciate your work on improving its readability. I have several concerns and appreciate your consideration:
It appears like the document defines the format of the Echo message. As I understand the RFC 5880, the format of the Echo message is not specified in the RFC 5880. It seems like by defining the format in this document, you affect RFC 5880 compliance of implementations that do support RFC 5880 as it exists today.

[XM]>>> As far as I can tell, several vendors have implemented this feature and nobody reports the problem.




The draft, in my opinion, significantly changes the architecture of the BFD, as it is defined in RFC 5880. I believe that characterizing Echo as a function stresses its dependency from a BFD mode, Asynchronous and Demand. The changes proposed in this draft are very extensive and severely affect the existing architecture of BFD by setting the Echo function on par, unrelated with the BFD modes.

[XM]>>> Please see above.




Also, I think that the normative language in the last paragraph of the Secrity Considerations sections are too soft. Currently used recommendation level, in my opinion, is insufficient and should be brought to the requirement level. I.e., I propose s/RECOMMENDED/MUST/ and s/SHOULD NOT/SHALL NOT/

[XM]>>> I agree we can strengthen the requirements for security. I'll incorporate the changes you proposed if no objection from others.




In conclusion, I am very much concerned with the amount of changes to the BFD architecture proposed in the document. I am also concerned with the affect on the protocol conformance standing of the established BFD implementations, SH BFD in particular. Hence, I propose changing this draft to the Experimental track.

[XM]>>> As said, I have different opinion on the implication of this feature. As to the Standards Track vs Experimental Track, I'm open to it, I personally prefer the former.





Cheers,

Xiao Min




Regards,
Greg




On Tue, Mar 21, 2023 at 11:02 AM Jeffrey Haas <[e-mail]> wrote:

Working Group,
 
 https://datatracker.ietf.org/doc/draft-ietf-bfd-unaffiliated-echo/05/
 
 The authors of draft-ietf-bfd-unaffiliated-echo have requested WGLC.
 
 The draft, in my opinion, is in fairly good shape.  However, since it
 functions via looping packets back to itself and trying to exercise the
 normal RFC 5880 state machine behaviors to a large extent, the draft could
 use very high scrutiny for several matters:
 
 - Does the state machine behave appropriately at all stages?
 - Are the descriptions of the values of the BFD fields clear in all cases?
 
 Please supply the authors and the Working Group with your feedback.
 
 The intended finish date for this WGLC is 7 April, 2023.  This is one week
 after the end of IETF 116.
 
 Note that Reshad is an author on the draft, so I'll be handling the full set
 of review and shepherding work.
 
 -- Jeff