Subject: Re: [RPSEC] BGP Requirements Draft

From: Sandy Murphy <[email-masked]>
Date: Mon, 26 Sep 2005 10:19:25 -0400 (EDT)

>- -- Verifying each AS along the path has touched the route actually
>proves authorization to transit? No.

Yes - because that is my definition of authorization.  If that's not
your definition of authorization, we won't agree.

>- -- Verifying each AS along the path has touched the route is the only
>mechanism whereby someone could prove authorization to transit? No.

Don't think I ever said this was the only way.
Proving a mechanism was the only mechanism to provide some desired
property would be an interesting result, for sure.

>Since the answer to both questions is "no," I don't see how someone can
>assign "relative security capabilities" to these two checks.

Right now, we're talking about loop freedom.  I thought.  Did you change
the problem statement?

Just out of curiousity - in the example where D announced (D,B,A) to
E and the path adjacency check says this is fine - do you think that
it *is* fine?  You're OK with D announcing that?  Even though B had
not announced the route to D?  This is an important question.  It is
a case that the path adjacency allows that I think is odd.  This has
nothing to do with loop freedom, it is a separate question.

--Sandy

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From: Russ White <[email-masked]>
Date: Mon, 26 Sep 2005 11:09:42 -0400

> your definition of authorization, we won't agree.

You obviously believe that authorization has to do with the 
authorization to send something you've received to someone else. This 
has little to do with routing, where there are two types of authorization:

- -- Authorization to transit traffic.
- -- Authorization to originate reachability.

That's part of the confusion here. There's no concept of "I authorize 
you to send these X bits to your peers."

> property would be an interesting result, for sure.

Since there are an infinite number of mechanisms, and I know of at least 
one other mechanism with this result, I think it's a lost cause. :-)

> Right now, we're talking about loop freedom.  I thought.  Did you change

Well, the topic seems to be wandering. On the topic of loop freedom, I 
don't see how that's on topic at all.

> nothing to do with loop freedom, it is a separate question.

If E sends the traffic to D, and D to B, will it reach A? If so, then 
it's a valid route, from a routing perspective. It might be "out of 
policy," but that's another problem altogether.

:-)

Russ

- -- 
[email-masked] CCIE <>< Grace Alone