Alternative to NetFlow for Measuring Traffic flows
Joe Abley
jabley at isc.org
Tue Dec 17 03:37:30 UTC 2002
On Monday, Dec 16, 2002, at 22:28 Canada/Eastern, Richard A Steenbergen
wrote:
> On Mon, Dec 16, 2002 at 09:16:55PM -0500, K. Scott Bethke wrote:
>>
>> based on ALL the ASN's of the people on the peering switch.. but in
>> most
>> cases anyone pushing any real traffic will probably not have fine
>> grained
>> samples enough to determine a peering relationship based on a single
>> AS
>> with this method. Maybe Im wrong but hey if you are taking 200megs
>> from any
>> one ASN I would hope you knew about it.
>
> Also, that method has the same "knowing the routes" problem as netflow.
> Whereever you are getting your list of ASN's route ASN.*"'s routes,
> there
> is pretty much no way they are accurate (for an ASN of ANY size).
>
> You would have to statically route (or otherwise inject routes with a
> specific nexthop) a list of their customer prefixes that would have to
> be
> manually transmitted.
If you are interested in traffic *to* a particular destination, surely
you could just tweak localpref on routes based on an as-path filter?
If you are interested in traffic *from* a particular destination (you
have a network full of eyes, not content) then this approach is not
useful anyway.
Joe
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