Subject: [lisp] Issue Title (number): Map-Reply Security (69)

From: Darrel Lewis <[email-masked]>
Date: Tue, 20 Jul 2010 14:11:38 -0700

Issue Title (number): Map-Reply Security (69)
Draft Section: 6.1.5.1
Issue Description: Solution inaduquate
Comments:

This is Comment 25 of Rekhter's review

Section 6.1.5.1

This section correctly identifies an attack where an ETR overclaims,
saying that it owns a larger span of prefixes than it really does. The
proposed solutions seem inadequate; in particular, the limiting the
mask-length that you'll accept from a given ETR seems weak. I.e., how
could an ITR determine a "configured prefix length" for a given EID
prefix?

This is a serious deficiency. It is somewhat analogous to the weakness
of the BGP routing system, except that it is much less amenable to
auditing than BGP (since the mapping data is only presented on demand,
an auditor can't simply get a feed) and there are many more machines
playing than in the BGP system.

(Note by Darrel- there is an existing issue (i think 27) in the tracker covering this topic.)

Response:

Dear Yakov-

Thank you for your contribution to draft-ietf-lisp-06.txt. The draft authors
have reviewed your comments but are cannot determine whether changes should
be made to the document. A partial answer is that the mapping system can
protect against this threat.  If a site is overclaiming due to a 
configuration error, the map-server will detect it.  Since this is an 
existing open issue, there is work on signing Map-Replies that can help this 
situation. We want to emphasize that is work in progress (initiated by the
earlier comments of Sam Hartman and others). Please bring this 
issue to the LISP working group mailing list, [email-masked], for further 
discussion. Should the WG reach consensus that changes are required, the 
authors will incorporate appropriate text into a future version of the draft.

	Thanks!
	Darrel, for the LISP document authors