Subject: Re: [lisp] LISP EID Block Size

From: [email-masked] (Noel Chiappa)
Date: Thu, 31 Oct 2013 15:54:53 -0400 (EDT)

> From: Roger Jorgensen <[email-masked]>

    > The _big_ difference between EID's out there today, and the one from
    > this new netblock are that any system should _know_ by matching the IP
    > that this is EID space, and by that know how to handle it.
    > If traffic grow as everyone predict, and continue todo so, optimizing
    > the handling of LISP EID's is probably a very good idea.

Sure, but realize that there are limits on the improvement of basic LISP
handling.

E.g. if we allocate a large number of PI blocks from a large EID block, an
ITR will likely _still_ have to do a mapping lookup cycle in order to be able
to forward traffic to an PI EID block's ETR. (Since there would be many
different PI blocks allocated from that large PI block, scattered all over
the Internet.)

Yes, the 'interoperation with legacy hosts' part would be better, since there
would only need to be a single large advertisement into the legacy DFZ (as
someone else pointed out).

And who knows, maybe someone will develop a use-case in which 'facial' EIDs
bring more significant benefits. But I think Darrel's point is very accurate:
"we should keep our expectations for the benefits of this block modest".

	Noel

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From: George Michaelson <[email-masked]>
Date: Thu, 31 Oct 2013 20:41:25 +0000

you can achieve this goal from a /32. what you're seeking to avoid is
having to re-map the magic prefix if the experiment is a success: this I
understand. But the cost of wiring a prefix is a very high cost: code
should be written to be agile and be able to be TOLD what prefix is the
magic prefix. Nobody should be reifying prefixes into anything, experiment
or otherwise.

Make it a parameter of prefix/len.

And work the experiment in a /32

On Thu, Oct 31, 2013 at 7:54 PM, Noel Chiappa <[email-masked]>wrote:

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From: Dino Farinacci <[email-masked]>
Date: Thu, 31 Oct 2013 19:29:51 -0400

> And work the experiment in a /32

I could agree on both counts. And if you wanted to latch the /32 on a DNS name, then implementations could make use of the level of indirection to allow the prefix to change. 

Dino