[Outages-discussion] [outages] Intermittent Level 3 outage/connectivity issues on Dallas edges?

[Jay Ashworth]

[ moving to -discuss ]

----- Original Message -----
> From: "Jeremy Chadwick" <jdc at koitsu.org>

> What you showed in Item #3 (your TW Telecom link) **does** show packet
> loss, but I cannot tell (without Item #4) if it's on the return-path or
> the forward-path. I understand "your TW Telecom link is working fine"
> but the 0.1-0.2% packet loss indicates it may not be as good as you
> think. That may be a separate issue however, or may be by design
> (QoS-like rules applied on router, etc.).
> 
> Make sense? :-)

It might make sense to him, or even to you, but it doesn't to me.

At each hop in an outbound trace, is it not true that the route which
the reply packets will take back to you might itself be different, depending
on *that device's* view of the routing tables, just as a trace from the 
actual destination device back to the origination point may take a different
route from the trace to it?

I never thought about that before you pressed the point just now, but ISTM
that given asymmetrical routing, there's no guarantee that the pongs on a
trace *to* something will come back along the path over which they got to
those intermediate routers...

Cheers,
-- jra
-- 
Jay R. Ashworth                  Baylink                       jra at baylink.com
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