Subject: Re: [lisp] #53: Reachability between ETR and EID (review by Y. Rekhter)

From: "lisp issue tracker" <[email-masked]>
Date: Wed, 16 Mar 2011 09:43:22 -0000

#53: Reachability between ETR and EID (review by Y. Rekhter)

Changes (by luigi@…):

  * status:  new => resolved
  * resolution:  => fixed

Comment:

 Authors replied on the mailinglist that in their opinion there is no need
 to make any change to the draft. Neither the original person that raised
 the issue nor the mailinglist stated a different opinion.

-- 
-------------------------------+--------------------------------------------
Reporter:  wmhaddad@…          |        Owner:                 
    Type:  technical           |       Status:  resolved       
Priority:  major               |    Component:  draft-ietf-lisp
Severity:  -                   |   Resolution:  fixed          
Keywords:                      |  
-------------------------------+--------------------------------------------

Ticket URL: <http://trac.tools.ietf.org/wg/lisp/trac/ticket/53#comment:1>
lisp <http://tools.ietf.org/lisp/>
LISP WG document issues

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From: "lisp issue tracker" <[email-masked]>
Date: Wed, 16 Mar 2011 09:43:44 -0000

Changes (by luigi@…):

  * status:  resolved => closed

    Type:  technical           |       Status:  closed         

Ticket URL: <http://trac.tools.ietf.org/wg/lisp/trac/ticket/53#comment:2>
lisp <http://tools.ietf.org/lisp/>
LISP WG document issues

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From: "lisp issue tracker" <[email-masked]>
Date: Wed, 16 Mar 2011 19:27:52 -0000

Changes (by yakov@…):

  * status:  closed => reopened
  * resolution:  fixed =>

Comment:

 In order to close the ticket the authors need to answer the question
 raised in the ticket.

-- 
-------------------------------+--------------------------------------------
Reporter:  wmhaddad@…          |        Owner:                 
    Type:  technical           |       Status:  reopened       
Priority:  major               |    Component:  draft-ietf-lisp
Severity:  -                   |   Resolution:                 
Keywords:                      |  
-------------------------------+--------------------------------------------

Ticket URL: <https://wiki.tools.ietf.org/wg/lisp/trac/ticket/53#comment:3>
lisp <http://tools.ietf.org/lisp/>
LISP WG document issues

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From: "lisp issue tracker" <[email-masked]>
Date: Thu, 17 Mar 2011 16:40:43 -0000

Comment(by yakov@…):

 From the response to my original comment:

   Thank you for your contribution to draft-ietf-lisp-06.txt. The draft
 authors
   have reviewed your comments but do not feel that changes to the document
 are
   warranted at this time. Remember that on-going locator reachability is
 not conveyed
   by the initial Map-Reply.

 To close the ticket please replace the following (from section 6.3 item
 5):

                                  The RLOC source of the Map-Reply is
        likely up since the ETR was able to send the Map-Reply to the
        ITR.

 with the following:

       The RLOC source of the Map-Reply was up at the time the ETR was able
       to send the Map-Reply to the ITR. However, the RLOC source may no
 longer
       be up even at the time the ITR receives the Map-Reply, and certainly
 may
       not be up after the ITR receives the Map-Reply, as the Map-Reply
 does
       not convey on-going locator reachability.

Ticket URL: <http://trac.tools.ietf.org/wg/lisp/trac/ticket/53#comment:4>
lisp <http://tools.ietf.org/lisp/>
LISP WG document issues

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From: Eliot Lear <[email-masked]>
Date: Thu, 17 Mar 2011 17:47:38 +0100

I don't agree with this proposed changed, as it is overly pessimistic, a
common thread.  In all likelihood, the ETR *is* up.  There will be cases
where the ETR fails, and those circumstances should be discussed (I
believe they are, albeit elsewhere).

Eliot

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From: Yakov Rekhter <[email-masked]>
Date: Thu, 17 Mar 2011 11:00:02 -0700

Eliot,

> common thread. 

"pessimistic" is not a valid technical reason to reject the change.

> In all likelihood, the ETR *is* up.  

Could you quantify the likelihood ?

Yakov.

> There will be cases

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From: Eliot Lear <[email-masked]>
Date: Thu, 17 Mar 2011 19:36:57 +0100

Yakov,

> "pessimistic" is not a valid technical reason to reject the change.

Optimistic and pessimistic design are two classic system design
approaches.  The Internet is largely based on optimistic design (e.g.,
packets can drop and the world doesn't stop).  Your text appears to come
from the point of view of pessimistic design.  I don't agree with that
approach.  I'm not saying the system shouldn't be hardened, but perhaps
not everything has to happen in a single document?  Otherwise RFC 791
would have been quite large!

> Could you quantify the likelihood ?

Happily.  By way of example, my consumer-grade router has been up and
available over 99.98% of the time over a year.  I'm not saying I'm
average, but I doubt I'm far from it.

Eliot