Subject: Re: [lisp] Map-Request error

From: [email-masked] (Noel Chiappa)
Date: Fri, 20 Nov 2009 16:06:43 -0500 (EST)

> From: "Joel M. Halpern" <[email-masked]>

    > LISP does have negative replies.

Oh, right you are, I missed that - thanks!

    > For a map request to get to an ETR which is not authoritative would
    > imply something went wrong in the ALT.

Umm, no. In addition to dimwits (programming error, etc) there is a real
circumstance that could provoke this: an RLOC Probe to a cached ETR which has
since been removed as a valid ETR for a given destination EID. (I'm on a LISP
protocol big-hunt... :-)

    > Te interesting problem in this case is that it is not at all clear that
    > an error reply to the ITR (the normal target of ETR map responses),
    > could do anything with such a message.

I would think the proper response in such a case as above (once you have
detected that there is a problem, which is why I was enquiring about the
error message :-) is to drop the cached mapping, and (probably) request a new
one.

	Noel