Re: AS sets and sequences

Gregory,

sorry but administrator can't force anything.
sFlow will show what it see in the packet, without any treatment.
May be you can use some tool to do that but I don't know one.

On Wed, Jan 14, 2009 at 5:42 PM, <gregory@is.naist.jp> wrote:

> 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 14:30:30 2009