Re: What Am I measuring

From: Hans Wouters (hans.wouters@belbone.net)
Date: Mon Apr 09 2001 - 08:36:18 PDT

  • Next message: Pierre Vander Vorst: "Re: What Am I measuring"

    Hi,

    First off all tanx for the reply, but

    Since I'm not only getting the peer-as as the source as, and peer-as is
    definitely configured on my routers, what could be wrong ?

    Greetings,

            Hans

    On Mon, 9 Apr 2001, Pierre Vander Vorst wrote:

    >
    > Hi Hans,
    >
    > > If I look to the data for a dedicated interface to one of my peers, I get
    > > different AS's as source AS.
    > > I tought that if you were running in the configuration described above,
    > > that you only could get 1 AS as source since I'm only measuring incoming
    > > traffic on the links where I have flow export configured.
    >
    > If peer-as is configured, the src AS will be the BGP neighbor. And indeed
    > you'll only count the incoming traffic on the NetFlow-enabled interface.
    > Unless you configured NetFlow egress, but this is another story.
    >
    > > Am I only receiving incoming traffic on, these links ?
    >
    > NetFlow cares only about incoming traffic.
    >
    > > Because, if I count the 5 minute data on a link I get almost 10 procent
    > > less traffic , than when I watch my mrtg interface statistics.
    >
    > MRTG is SNMP based, and the SNMP counters are including the L2 headers.
    > NetFlow is only counting L3 and above. That is probably the explanation.
    > Check the SNMP FAQ's :
    >
    > http://www.cisco.com/warp/public/477/SNMP/snmp_faq.html
    >
    > Regards,
    >
    > Pierre
    >
    > > From cflowd-owner@ipn.caida.org Mon Apr 9 17:17:29 2001
    > > Return-Path: <cflowd-owner@ipn.caida.org>
    > > X-Authentication-Warning: ipn.caida.org: petidomo set sender to cflowd-owner@caida.org using -f
    > > Date: Mon, 9 Apr 2001 17:09:08 +0200 (CEST)
    > > From: Hans Wouters <hans.wouters@belbone.net>
    > > To: cflowd@caida.org
    > > Subject: What Am I measuring
    > > Sender: cflowd-owner@ipn.caida.org
    > > Precedence: list
    > >
    > > Hi,
    > >
    > > I have flow export version 5 , peer-as configured on my routers.
    > > I'm running CFLOWD and I'm collecting AS-MATRIX data.
    > >
    > > If I look to the data for a dedicated interface to one of my peers, I get
    > > different AS's as source AS.
    > >
    > > I tought that if you were running in the configuration described above,
    > > that you only could get 1 AS as source since I'm only measuring incoming
    > > traffic on the links where I have flow export configured.
    > >
    > > Am I only receiving incoming traffic on, these links ?
    > > Because, if I count the 5 minute data on a link I get almost 10 procent
    > > less traffic , than when I watch my mrtg interface statistics.
    > >
    > > Can anyone clarify, or point me in the direction of some reading on this
    > > subject.
    > >
    > > Greetings,
    > >
    > > Hans
    > >
    > > --
    > > Hans Wouters
    > > IP operations engineer
    > > BELGACOM INTERNET BACKBONE
    > > HW3341-RIPE
    > >
    > > --
    > > cflowd mailing list
    > > cflowd@caida.org
    > >
    >

    -- 
    Hans Wouters
    IP operations engineer
    BELGACOM INTERNET BACKBONE
    HW3341-RIPE
    

    -- cflowd mailing list cflowd@caida.org



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