Re: [RRG] Geographic aggregation-based routing

["William Herrin" <bill@herrin.us>]

On Sat, Jul 12, 2008 at 12:31 PM,  <HeinerHummel@aol.com> wrote:
> In einer eMail vom 12.07.2008 18:16:25 Westeuropäische Normalzeit schreibt
> bill@herrin.us:
>
>>> http://bill.herrin.us/network/geoag-h1.gif.
>>
> >Okay, good. Now, based on the graph you just agreed to and the two FIB
> >tables you just agreed to, route a packet from node H to node A. The
> >path I compute is H->G->F->B->A. Do you get that path as well?
>
> Sure.

There is your error. You violated the permission constraint: F is not
a permitted node in the transit path between H and A. There is no
trail of green arrows from H to F. There is also no trail of green
arrows from A to F. Hence F is not permitted for a packet whose
addresses are H and A.

There is one permitted path from H to A:  H->G->C->B->A. Each node in
that chain has a trail of green arrows leading to it from either H or
A. This designates permission.

Would you like to redraw your red arrows? Can you think of a
configuration of red arrows where you get *both* H->G->C->B->A *and*
D->C->G->F->E ?

-Bill

-- 
William D. Herrin ................ herrin@dirtside.com bill@herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004

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