Subject: [rrg] Questions about LISP+ALT

From: [email-masked]
Date: Wed, 25 Nov 2009 17:58:21 EST

Michael Menth wrote to the LISP-mailinglist (without getting any  
onlist-response) a while ago:
 
___________
Dear colleagues,

I have some questions about LISP+ALT since some  pieces of that 
architecture are not yet clear to me. Either I have  overlooked that 
information in the drafts or they are not yet publicly  available.

1) The question of control

Who has the control over  ALT? Who decides what the aggregation points are?

2) Who's paying for the  map-request traffic?

In LISP+ALT, map-requests are carried over the ALT.  In contrast, data 
traffic is carried over paths provided by "traditional  BGP" for which 
intermediate carriers are obliged by contracts to carry the  traffic. 
What are the incentives for providers to forward map-requests if  they 
have no relations to the source or destination of that traffic. This  
situation seems possible or even likely to me for aggregation  nodes.

a) Does the ALT topology follow contract relationships like the  normal 
BGP which possibly makes aggregation difficult?

b) Will there  be extra contracts to carry map-request traffic on the ALT`?

c) Or will  that work with mutual agreements since the overall rate of 
the map-request  traffic is hopefully small enough to be carried without 
financial  backing?

Or is there another option?

3) The structure of the ALT  and data-probes

What are the guideline for designing the paths in the  ALT? Business and 
trust relationships dominate the paths in the normal BGP.  Aggregation 
should be the objective in the ALT, right? Can't that lead to  extremely 
long paths when EID-prefix-aggregators on different levels are  located 
in different areas? This adds to delay which is especially  unfortunate 
for data-probes which are currently not considered in ALT. What  was 
actually the reason to renounce on data-probes in the current version of  
LISP?

4) Resilience

LISP+ALT uses ETRs as authoritative  sources of the mappings and 
map-requests are delivered to them over the ALT.  Multihomed networks 
have several ETRs which improve their availability.  Which mechanism 
makes sure that map-requests are deviated to another ETR if  the primary 
ETR fails?

5) Security

Are there plans yet to add  security in LISP+ALT?

Kind regards,

Michael
_____________________
 
Patte presented his ideas about some hierarchy in  scalable_routing.doc.
 
No one ever answered, neither on the LISP nor RRG mailinglist. All who  
support such solutions (LISP and the many variants)  should comment on  the 
reproach, that the distributed database (ALT) in mind would be extremely  
vulnerable (who owns these mapping servers, will own the internet; who can  
attack successfully them will tear down the entire internet).
 
Heiner

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From: [email-masked] (Noel Chiappa)
Date: Wed, 25 Nov 2009 23:08:22 -0500 (EST)

> From: [email-masked]

    > onlist-response) a while ago:

The message you refer to:

  http://www.ietf.org/mail-archive/web/lisp/current/msg00792.html

was sent to the WG mailing list in the middle of a mailstorm (~55 messages
over that day and the next day, out of about several hundred over about 2
weeks) about UDP checksums; in the midst of all that, this message got
overlooked.

Since it's LISP-specific, I'll answer it over there.

	Noel