Subject: Re: [Idr] I-D Action: draft-ietf-idr-error-handling-14.txt

From: Rob Shakir <[email-masked]>
Date: Thu, 16 Oct 2014 14:25:24 +0100

Hi John, IDR,

On 3 Sep 2014, at 20:39, John G. Scudder <[email-masked]> wrote:

> 
> In short, it removes the discussion of what it means for an NLRI to be incorrect.
> Reviewers may want to pay particular attention to S. 7.11.

Sorry for the delay in sending over some comments.

First off, thanks to the authors for the work on this doc — it’s taken something that 
we’ve debated in length on the IDR list and resulted in (IMHO) a very clean document 
that does a good job of explaining the motivation and revisions to the error handling 
behaviour.

I had some very minor comments:

	- Currently, when the text discusses attribute discard, it links this to 
	  something that cannot affect the route selection. Since in most routing 
	  policy languages, one could potentially match on /any/ attribute if one
	  so wanted, then I was wondering whether it was worth adding something into
	  the operational considerations section that briefly noted that operators
	  SHOULD NOT implement policies which influence route selection based on an
	  attribute that might be discarded.

	- In 7.16, we re-define the error handling for BGP ELC, but I noted the
	  existence of draft-ietf-idr-mpls-deprecate-bgp-entropy-label. I’m not sure
	  whether it is still worth including this analysis, or whether it is worth
	  noting that this attribute is (likely to be) deprecated.

Other than this, thanks again for the work on this document.

Kind regards,
r.

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From: "John G. Scudder" <[email-masked]>
Date: Wed, 22 Oct 2014 15:41:24 -0400

Rob,

Thanks for your comments. With regard to the first, how do you (and the WG) feel about this paragraph for the end of the Operations section?

   Section 8 mentions that attribute discard should not be used in cases
   where "the attribute in question has or may have an effect on route
   selection."  Although all cases that specify attribute discard in
   this document do not affect route selection by default, in principle
   routing policies could be written which affect selection based on
   such an attribute.  Operators should take care when writing such
   policies to consider the possible consequences of an attribute
   discard.  (In general, as long as such policies are only used on
   external BGP sessions, correctness issues are not expected to arise.)

Regarding ELC, thanks for catching that! Considering that we're excluding deprecated attributes from consideration in this document, and considering that draft-ietf-mpls-deprecate-bgp-entropy-label has been approved for publication as an RFC, I think it's safe for me to remove all references to RFC 6790. 

Regards,

--John

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From: "John G. Scudder" <[email-masked]>
Date: Fri, 24 Oct 2014 12:51:39 -0400

Posted as -15.

--John

On Oct 22, 2014, at 3:41 PM, John G. Scudder <[email-masked]> wrote:

> _______________________________________________
> Idr mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/idr

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From: Rob Shakir <[email-masked]>
Date: Fri, 24 Oct 2014 17:53:19 +0100

Hi John,

Sorry — yes, this looked good to me. I had the original mail flagged to reply to, my apologies.

Thanks for the changes!
r.

> On 24 Oct 2014, at 17:51, John G. Scudder <[email-masked]> wrote:
> 
> Posted as -15.
> 
> --John
>