Re: AS sets and sequences

Renan,

thank you for your diligence.
Well, I do understand how the AS path is built but, sorry for the long sentences I made in the previous mail, I just wanted to know if sFlow had a say in whether to represent this AS path as a set (unordered) or as a sequence (ordered). In the latter case, it may possible for the sFlow administrator to force the representation of this AS path.
Isn't it?

Gregory

----- Original Message -----
From: Renan M Alves <renanmalves@gmail.com>
Date: Thursday, January 15, 2009 4:29 am
Subject: Re: [sFlow] AS sets and sequences

> Gragory,
>
> the order of ASs in a AS path is totaly determined by the routing
> protocol,commonly BGP, and represent the best path between two
> points (ASs).
> Sflow can't do anything about this, it just show what BGP decide.
>
>
>
>
> On Wed, Jan 14, 2009 at 3:29 PM, <gregory@is.naist.jp> wrote:
>
> > Hello,
> >
> > I may have missed something in the RFC, but I was not able to
> determine why
> > the destination AS path can sometimes be represented as a set
> (unordered set
> > of ASs) or sometimes as a sequence (ordered set of ASs). Is it
> bound to the
> > proximity of the destination? For example, in a case where the
> packet is
> > sampled far from its destination and there are still many ASs to
> cross, not
> > ordering the ASs in the destination AS path may save processing
> time (?).
> > Or is there a totally different reason to this distinction?
> > Moreover, is it possible to force the AS path to be either one or
> the other
> > in some sampling device implementations, especially routers? I
> can not
> > recall anywhere to configure the way the AS path is exported on
> the devices
> > I use. So I was wondering if it was automatically determined by an
> > algorithm.
> >
> > Well, my reasoning is way too long. Sorry.
> >
> > Thanks for the answer,
> >
> > Gregory.
Received on Wed Jan 14 11:44:54 2009