Re: Inter-Domain AS-Path failures

[Goetz Lichtwald <]

On Mon, 2005-02-28 at 16:12 +0100, Daniel Roesen wrote:
> On Mon, Feb 28, 2005 at 03:51:57PM +0100, Goetz Lichtwald wrote:
> > On Mon, 2005-02-28 at 15:28 +0100, Daniel Roesen wrote:
> > > On Mon, Feb 28, 2005 at 03:09:31PM +0100, Goetz Lichtwald wrote:
> > > > for research purpose I am looking for some facts concerning 
> > > > inter-domain AS-path failures.
> > > 
> > > What are "inter-domain AS-path failures"? Please specify.
> > 
> > I regard an inter-domain as-path failure as a failure, where
> > the BGP "hold-timer" expires (for whatever reason).


Sorry for being still too imprecise. 

> So you mean specifically BGP sessions timing out (session flaps)?
> Or do you actually mean any session shutdown (for whatever reason)?

I want know -- in real life -- how often BGP regards an AS-path to
be broken, i.e. no KEEPALVIE messages can be exchanged -- at least 
that is what BGP "thinks". This should result in an "BGP session timing
out" (your first point). 

From rom my understanding BGP tries to reestablish the BGP session for 
a certain time (ConnectRetry timer) and waits for an incoming BGP
session request. So, concerning your second remark I am not quite
sure if I got the point. Where is the difference between them? Is
there a "meta-state" between a "session flap" and a "shut down"?

Anyway, for me it is important to get a feeling of how many of those
session flaps occur with a duration on less than appr. 10 minutes.


kind regards,

 - goetz

-- 
Dipl. Inform Goetz Lichtwald
University of Karlsruhe, Germany
Institute of Telematics
Zirkel 2, 76128 Karlsruhe
Phone:   +49 (0) 721 - 608 6404
Fax:     +49 (0) 721 - 608 6789
PGP-Key: http://www.tm.uka.de/~lichtwald/mykey.asc

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