Subject: I-D Action:draft-iannone-lisp-mapping-versioning-00.txt

From: [email-masked]
Date: Tue, 3 Mar 2009 10:15:02 -0800 (PST)

A New Internet-Draft is available from the on-line Internet-Drafts directories.

	Title           : LISP Mapping Versioning
	Author(s)       : L. Iannone, et al.
	Filename        : draft-iannone-lisp-mapping-versioning-00.txt
	Pages           : 22
	Date            : 2009-03-03

The present document sketches an alternative approach to provide
information about changes to EID-to-RLOC mappings in the context of
LISP.  The proposed approach is based on a versioning system for the
EID-to-RLOC mapping itself.  When there is a change in the mapping
(where change could mean adding/removing an RLOC or just a
modification in the priority or weight of one or more RLOCs) a new
version number is generated and propagated in the LISP data packet.
In the LISP context, ETRs do not keep state that allows to know when
an ITR changes a mapping.  The versioning system is a data-driven
mechanism to annonce those changes.

In order to support such an approach, the LISP encapsulation need to
be modified.  In particular LISP-encapsulated data packets have to
contain the version number of the mapings used to select the RLOCs in
the outer header.  These version numbers are contained in a "new"
LISP header.

The mappings are distributed as usual through the mapping
distribution system (e.g., CONS, ALT); versioning is only a mean to
announce that something has changed in the mapping.  The
infrastructure built by each specific mapping protocol does not
change anyhow.  Nevertheless, two modifications are needed.  The
first modification consist in including version number in the Map-
Reply messages.  The second modification consist in the introduction
of a new message, the "Map-Update-Notification" message used by ETRs
to notify ITRs that the mapping used to encapsulate the packet is old
and needs to be updated.  This message does not contain the mapping,
it just suggests ITRs to perform a Map-Request in order to retrieve
the updated mapping.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-iannone-lisp-mapping-versioning-00.txt

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

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