North American Network Operators Group
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Re: Split flows across Domains

  • From: Christopher L. Morrow
  • Date: Tue Jan 24 10:46:03 2006 
On Tue, 24 Jan 2006, Robert E.Seastrom wrote:

>
>
> Glen Kent <[email protected]> writes:
>
> > For example, an ISP can learn two different equal cost routes to a
> > foo.com server via two different autonomous domains. It can thus split
> > different flows (based on src-dest IP, src-dest Port, TOS, etc) across
> > these two paths.
> >
> > Do operators currently do this?
> >
> > Folks can send me replies offline in case this constitues a "trade secret"!
>
> Works great with a flow-based router (or layer-three-switch-pronounced-
> 'crippled-router').  The downside, of course, is that you now have a
> flow-based router in your network, which has been shown to Not Work
> Well under other specified conditions (worm outbreaks come immediately
> to mind).

I could be mistaken, but this is also a feature in mbgp, effectively
loadsharing across two external paths. I presume the paths would have to
be completely equal all the way down to the router-id and (probably)
age-of-route ...