Re: [mpls] working group last call for draft-ietf-mpls-lsp-ping-reply-mode-simple-01

["Nobo Akiya" <[e-mail]>]

Hello Adrian,

 

Many thanks for your comments.

 

Please see in-line with [NOBO].

 

From: mpls [mailto:[e-mail]] On Behalf Of Adrian Farrel
Sent: April-07-15 1:58 PM
To: 'Ross Callon'; [e-mail]
Cc: [e-mail]; 'Loa Andersson'
Subject: Re: [mpls] working group last call for
draft-ietf-mpls-lsp-ping-reply-mode-simple-01

 

Hi,

 

I have read the most recent revision of this document and have no objection
to the WG requesting its publication.

 

I have some comments that I think should be addressed before publication.

 

Thanks,

Adrian

 

I don't believe this document updates 4379. It certainly does not

explain how it updates 4379, and since 7110 did not update 4379, it

seems unlikely that this document does. However, if the authors feel that

it is intended to update 4379 (i.e., an implementation of 4379 will not

be complete without also including the function of this document, for 

example, there is a problem in 4379 that this document fixes) then the

document needs to explain what the update is and how 4379 implementations

are affected.

 

I *can* believe that this document updates 7110, but it needs to explain

it and (presumably) observe that 7110 is not complete without this

document. (Actually, section 3.1 has most of this text, but the

Introduction should make the clear linkage to the "update".)

 

[NOBO] Let me discuss this one with authors and get back to you.

 

---

 

Section 3.2 gives clear instructions and guidance on forming the Reply

Mode Order TLV but not on what to do if a received TLV deviates from the

MUST and MUST NOT instructions. Options might include ignoring errors,

ignoring the TLV, ignoring the message. But presumably not sending an

error response (because how would you know how to send it?)

 

[NOBO] That's a good point. What the document really state is that The Reply
Mode value 5 (Reply via Specified Path) MAY be repeated but all other Reply
Mode values MUST NOT be repeated. Will update the document to make it clear.

 

---

                                                     

The last guidance in 3.2 is:

 

   8.  Reply Mode value 1 (Do not reply) SHOULD NOT be used in the Reply

       Mode Order TLV.

 

"SHOULD NOT" means "you can do it if you have good reason." Please can

you explain the good reason and how the receiver should interpret a 

"Do not reply" mode coming, say, third in a list of five modes.

 

[NOBO] Another good point. Here, we should replace the "SHOULD NOT" to "MUST
NOT" as exhausting all specified reply mode options implicitly means that
the responder does not have any path to reply and no message will be send
anyways.

 

---

 

The security considerations are hard to believe!

At the very least, 7110 makes some security observations that surely

apply here.

 

[NOBO] At the least, we will reference RFC7110 in the Security Consideration
section. Additionally, we'll see if there are any additional vulnerabilities
exposed by the changes and add those (if any).

 

Thanks!

 

-Nobo

 

From: mpls [mailto:[e-mail]] On Behalf Of Ross Callon
Sent: 20 March 2015 14:04
To: [e-mail] <mailto:[e-mail]> 
Cc: Loa Andersson; [e-mail]
<mailto:[e-mail]> 
Subject: [mpls] working group last call for
draft-ietf-mpls-lsp-ping-reply-mode-simple-01

 

Working Group,

 

This is to initiate a working group last call on
draft-ietf-mpls-lsp-ping-reply-mode-simple-01.

Because this WGLC will span the IETF in Dallas, it will be extended to three
weeks. 

 

Please send your comments to the mpls wg mailing list ([e-mail]
<mailto:[e-mail]> ).

 

There are no IPR disclosures against this document. All the authors have
stated that they 

are not aware of any IPR that relates to this draft.

 

This working group last call ends Friday  April 10, 2015.  

 

Ross

for the MPLS WG chairs