[nsp] no AS# in netflow data on 7500

[Jay Ford]

On Wed, 19 May 2004, Marko Milivojevic wrote:
On Wed, 19 May 2004, fingers wrote:
> > I've got a bit of a wierd issue. I've got netflow (v5) exports from a few
> > routers. on the 7200's I see src_as and dst_as but not on the 7500's
> > (12.0(27.4)S1). I understand that my ASN will be 0, but not the dst_as
>
>     One silly question, but do you have full BGP table on that 7500 box? If
> you don't, then both src_as and dst_as will be 0. Also, make sure you have
> flow-export configured with "origin-as", not with "peer-as".

While it is the case that lack of BGP (AS-based) routing information for a
destination will lead to 0 dst_as values for flows to that destination, the
rest of that answer is too sweeping.  The dst_as will be filled in for
destinations with AS-based routing, & the src_as can still be non-zero for
some flows even if dst_as is 0.  Also, there is no one right choice for
"origin-as" or "peer-as";  it depends on what you want to track.

________________________________________________________________________
Jay Ford, Network Engineering Group, Information Technology Services
University of Iowa, Iowa City, IA 52242
email: jay-ford at uiowa.edu, phone: 319-335-5555, fax: 319-335-2951