Qwest Support

Richard A Steenbergen ras at e-gerbil.net
Fri Apr 5 01:49:14 UTC 2002


On Thu, Apr 04, 2002 at 05:39:41PM -0600, Steve Naslund wrote:
> 
> > Qwest's presence or absence from public IX's really has nothing to do with
> > your routes being announced. In fact, Qwest privately peers with all the
> > other large networks. While there are many peering sessions at the public
> > NAPs, most traffic is carried over private network interconnects, at least
> > domestically. Certain peering points in Europe (Linx), tend to
> > run the other
> > way.
> 
> If the routes cannot be seen at the public IXs then a lot of people who
> are connected to the public IXs will not see it either.  Depends if you
> are only talking to the "big networks".

I'm not aware of any tier 1's (those without transit) who rely on only 
public IX connections.

> > In fact, if Qwest were publically peering with other networks, it
> > might be a
> > reason why your routes through UUNet were being prefered - private peer
> > originated routes are almost always assigned higher local preferences in
> > carrier networks, then public peer originated routes.
> 
> Local prefs are just that LOCAL.  They will not matter to other
> networks, they merely show the routes I prefer in and out of my network.  
> This should have no impact on AS path hop counts which is the primary
> method of selecting BGP routes.

No, see http://www.amazon.com/exec/obidos/ASIN/157870233X/

> I think that most networks will not set a local pref unless there is a
> reason to override the default BGP behavior which is to use AS path
> length.

That would not be my experience.

> > carried throughout Network X via iBGP. If UUNet's routes "won" at all
> > those peering points, you will not see any paths through Qwest on a
> > single carrier route server like Nitrous.
> 
> Not true.  Nitrous shows all routes it knows about whether they are
> preferred or not.

Yes true. Once the path selection is made only the "best" path is passed 
on.

I'd suggest you listen to Dan, in my experience he tends to know what he 
is talking about.

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
PGP Key ID: 0x138EA177  (67 29 D7 BC E8 18 3E DA  B2 46 B3 D8 14 36 FE B6)



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