On 2/04/2007, at 3:32 PM, Alastair Johnson wrote:
Oldest path is configurable behavior - many people
prefer the more
deterministic lowest neighbor ID because it prevents neighbor
But it's not disabled default. My bet is that most people don't
really consider the pros/cons of each in great detail, and instead
opt for just-make-it-go.
You're also assuming that all providers use the
Route Servers and not
bilateral peering; which is a risky assumption.
From what I've seen, bi-lateral peering across the IXes is becoming
less and less common.
I'd generally assume anyone has a local_pref based
on cost: ie:
(speaking of risky assumptions.. :-)
highest local_pref for customer (ie. "getting
paid for") prefixes
second highest for second lowest cost/efficiency (private peering)
third highest for third lowest (public)
fourth highest for transit (or other)
Which fixes any problems with AS_PATH length.
Of course, I've seen a lot of networks that don't do things that you
and I take for granted, though :-)
You raise some valid points... except the prefix in
announced by any peer that I could see in any case, so there was no
determination being made.
Yep, the APE looking glass doesn't show any announcements either.
Based on your assumptions, it appears that you're much more of an
optimist than I.