Re: On the use of multiple PA prefixes or a single PI prefix for IPv6 multihoming

[Cedric de Launois <delaunois@info.ucl.ac.be>]

Le ven 22/10/2004 à 17:01, Michael H. Lambert a écrit :
> Given that the "best path" probably just has meaning for a given 
> application between given hosts at a given point in time, how often do 
> we *really* need the *best* path?

The goal is not much to have the *best* path, but to avoid really bad
paths.

> Best effort usually works well enough for forwarding--why shouldn't it 
> do the same for path selection? (I think Noel implied this in his 
> response--to use his highway analogy: in driving from Boston to San 
> Francisco saving six hours is good, saving ten minutes is (usually) 
> irrelevant?)
> 
> Since the One True Best Path is likely unknowable anyway, why 
> complicate path selection by building SVCs (or MPLS tunnels) into it?

In the multi-address multi6 case, path selection is simply done by
selecting the right source and destination prefixes. If a host can
figure out which are the couples (src,dst) prefixes to avoid, then the
benefit can be huge. This doesn't require tunnels in any ways.

Cedric