Subject: [lisp] #114: EID-to-RLOC mapping - transients

From: "lisp issue tracker" <[email-masked]>
Date: Wed, 16 Mar 2011 14:47:44 -0000

#114: EID-to-RLOC mapping - transients

 From section 3:

    EID-to-RLOC Database:   The EID-to-RLOC database is a global
       distributed database that contains all known EID-prefix to RLOC
       mappings.  Each potential ETR typically contains a small piece of
       the database: the EID-to-RLOC mappings for the EID prefixes
       "behind" the router.  These map to one of the router's own,
       globally-visible, IP addresses.  The same database mapping entries
       MUST be configured on all ETRs for a given site.  That is, the
       EID-prefixes for the site and locator-set for each EID-prefix MUST
       be the same on all ETRs so they consistently send Map-Reply
       messages with the same database mapping contents.

 During the time period when the EID-to-RLOC mapping changes, and a site
 has multiple ETRs the spec has to document the procedures by which all the
 ETRs of a given site "consistently send Map-Reply messages with the same
 database mapping contents".

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Reporter:  yakov@…            |       Owner:     
    Type:  technical          |      Status:  new
Priority:  major              |   Component:  alt
Severity:  -                  |    Keywords:     
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Ticket URL: <https://wiki.tools.ietf.org/wg/lisp/trac/ticket/114>
lisp <http://tools.ietf.org/lisp/>
LISP WG document issues

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From: "lisp issue tracker" <[email-masked]>
Date: Mon, 21 Mar 2011 09:06:26 -0000

Comment(by luigi@…):

 Reply sent by Vince Fuller:

  * Just as with routing protocols or any other distributed database, there
 will inevitibly be short windows where an update to the configuration on
 one device can lag an update to another device; configuring multiple ETRs
 with the same EID-to-RLOC mappings is no different. The existing text
 describes proper practice when configuration devices; the authors do not
 feel it is necessary to specifically state that the world won't come to an
 end if multiple ETRs with the same database mappings do not have their
 configurations updated at pricesly the same instant. If the issue author
 or another WG member believes that an explicit warning is necessary then
 the document authors welcome suggested text.

 '''Note:''' ticket will be closed Friday 25th March unless the responses
 noted here do not address the concern. If the concern is still not
 addressed substantive reasoning would be appreciated.

Ticket URL: <https://wiki.tools.ietf.org/wg/lisp/trac/ticket/114#comment:1>
lisp <http://tools.ietf.org/lisp/>
LISP WG document issues

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From: "lisp issue tracker" <[email-masked]>
Date: Mon, 21 Mar 2011 19:49:30 -0000

Comment(by yakov@…):

 To address the issue please add the following after "That is, the
 EID-prefixes for the site and locator-set for each EID-prefix MUST
 be the same on all ETRs so they consistently send Map-Reply
 messages with the same database mapping contents."

    Note that there may be transient conditions when the EID-prefix for the
 site
    and locator-set for each EID-prefix MAY not be the same on all ETRs. As
 a result,
    for the duration of these transient conditions not all the ETRs would
 be able to
    send Map-Reply messages with the same database mapping contents.

 Furthermore, if the authors think that sending inconsistent Map-Reply
 during transients has no negative implications, then add the following at
 the end of the text I suggested above:

    This has no negative implications.

 And if the authors think that sending inconsistent Map-Reply during
 transients does have negative implications, then the authors should list
 them following the text I suggested above.

Ticket URL: <https://wiki.tools.ietf.org/wg/lisp/trac/ticket/114#comment:2>
lisp <http://tools.ietf.org/lisp/>
LISP WG document issues

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From: "lisp issue tracker" <[email-masked]>
Date: Sat, 26 Mar 2011 09:05:07 -0000

Comment(by luigi@…):

 Reply sent by Vince Fuller,

  * In looking at the recent email exchange with Yakov over item #114, I
 don't see where this issue applies to draft-ietf-lisp-alt since it doesn't
 say anything about consistent ETR configuration. The suggested text
 changes would appear to the definition of "EID-to-RLOC Database" in
 section 3 of draft-ietf-lisp, that currently reads as follows:
     * EID-to-RLOC Database:   The EID-to-RLOC database is a global
 distributed database that contains all known EID-prefix to RLOC  mappings.
 Each potential ETR typically contains a small piece of the database: the
 EID-to-RLOC mappings for the EID prefixes "behind" the router.  These map
 to one of the router's own, globally-visible, IP addresses.  The same
 database mapping entries MUST be configured on all ETRs for a given site.
 That is, the  EID-prefixes for the site and locator-set for each EID-
 prefix MUST be the same on all ETRs so they consistently send Map-Reply
 messages with the same database mapping contents.

  Seems like the simplest fix for this is simply to delete the last part of
 the last sentence: "so they consistently send Map-Reply messages with the
 same database mapping contents". Mandating consistent configuration should
 result in sending consistent EID-to-RLOC mappings in Map-Reply messages.
 The extra text invites unnecessary (IMHO) discussion of transient cases.

Ticket URL: <http://trac.tools.ietf.org/wg/lisp/trac/ticket/114#comment:3>
lisp <http://tools.ietf.org/lisp/>
LISP WG document issues

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From: "lisp issue tracker" <[email-masked]>
Date: Wed, 30 Mar 2011 07:17:07 -0000

Changes (by terry.manderson@…):

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

Comment:

 As WG-Chairs we are closing this ticket. It is sufficient to document in
 draft-ietf-lisp that transients exist. As an experimental draft it is not
 necessary to require the draft to document all cases where the transient
 existence will cause a failure. That awareness can and will come, from
 experimentation and post analysis.

-- 
------------------------------+---------------------------------------------
Reporter:  yakov@…            |        Owner:          
    Type:  technical          |       Status:  resolved
Priority:  major              |    Component:  alt     
Severity:  -                  |   Resolution:  fixed   
Keywords:                     |  
------------------------------+---------------------------------------------

Ticket URL: <https://wiki.tools.ietf.org/wg/lisp/trac/ticket/114#comment:4>
lisp <http://tools.ietf.org/lisp/>
LISP WG document issues

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From: "lisp issue tracker" <[email-masked]>
Date: Wed, 30 Mar 2011 07:23:29 -0000

* status:  resolved => closed

    Type:  technical          |       Status:  closed

Ticket URL: <https://wiki.tools.ietf.org/wg/lisp/trac/ticket/114#comment:5>
lisp <http://tools.ietf.org/lisp/>
LISP WG document issues