Subject: Re: [lisp] ETR connectivity to site - question on EID reachability (section 6.4)

From: [email-masked] (Noel Chiappa)
Date: Mon, 23 May 2011 18:36:16 -0400 (EDT)

> From: Yakov Rekhter <[email-masked]>

    > Whenever draft-ietf-lisp-12 mentioned the term "ITR" or "ETR", then
    > unless stated otherwise, do these terms imply that ITR/ETR is a CPE
    > router ?

    > The *only* possible answers are "yes" or "no".

Is pink even or odd?

LISP (like all architectural enhancements) is a very general-purpose tool
(something I'm going to say a bit more about in a reply to Fred's message),
and it might work well in some particular circumstances, and not so well in
others.

So it might work well for most people as a CPE device, and not so well for
some; but it might also work well for some people in non-CPE applications.
Etc, etc... I don't really feel that it _has_ to necessarily fit into - or out
of - the 'CPE router' box. Sometimes it might, sometimes it might not.

Or perhaps I'm not understanding your question?

	Noel

---

From: "Joel M. Halpern" <[email-masked]>
Date: Mon, 23 May 2011 20:57:00 -0400

Speaking as an individual, I agree with Noel's response.

Speaking as chair, I have to say that you do not get to insist on a yes 
or no answer to a question.  There are relatively few questions in this 
technology that are well answered with "yes" or "no".  When we have 
those answers, we write "MUST" or "MUST NOT".  Even then, it often takes 
more than a few words, and usually takes describing the situation.  The 
rest of the time, we try to write enough words that people get it.

Returning to personal perspectives, I had great fun driving a lwayer 
crazy in a deposition because he kept trying to get me to answer a 
question with "yes" or "no", and I kept giving him a correct answer instead.

Yours,
Joel

On 5/23/2011 6:36 PM, Noel Chiappa wrote:
>      >  From: Yakov Rekhter<[email-masked]>
>
> _______________________________________________
> lisp mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/lisp
>

---

From: Yakov Rekhter <[email-masked]>
Date: Tue, 24 May 2011 06:16:16 -0700

Noel,

> Etc, etc... I don't really feel that it _has_ to necessarily fit into - or 
> out of - the 'CPE router' box. Sometimes it might, sometimes it might not.
> 

Let's step back and revisit the discussion that prompted this question.

yakov> 6.4.  EID Reachability within a LISP Site
yakov> 
yakov> A site may be multihomed using two or more ETRs.  The hosts and
yakov> infrastructure within a site will be addressed using one or more EID
yakov> prefixes that are mapped to the RLOCs of the relevant ETRs in the
yakov> mapping system.  One possible failure mode is for an ETR to lose
yakov> reachability to one or more of the EID prefixes within its own site.
yakov> When this occurs when the ETR sends Map-Replies, it can clear the
yakov> R-bit associated with its own locator.  And when the ETR is also an
yakov> ITR, it can clear its locator-status-bit in the encapsulation data
yakov> header.

dino> So note it says the site has the xTRs, so the context is respect to a
dino> CPE router doing LISP functionality.

yakov> Are you saying that a PE can not act as an xTR for a site connected
yakov> to that PE ?

dino> I am not saying that. I am indicating what the context of the above  
dino> paragraph is.

Does Dino's response mean that the 1st paragraph in 6.4 applies only 
when xTR is a CPE router, or also when xTR is a PE router ?

Yakov.