Yeah, cost to implement dst_as_path lookups far outweighs the usefulness IMO. If you really want that it's much better to get it via BMP. ( Same with communities and localpref in the extended gateway definition of sflow. )
Fundamentally I've always disagreed with how sFlow aggregates flow data with network state data. IMO you collect the two things separately, and join them off-device should you need to for analysis. On Thu, Mar 28, 2024 at 1:50 PM Saku Ytti <s...@ytti.fi> wrote: > Hey, > > On Thu, 28 Mar 2024 at 17:49, Peter Phaal <peter.ph...@gmail.com> wrote: > > > sFlow was mentioned because I believe Brian's routers support the > feature and may well export the as-path data directly via sFlow (I am not > aware that it is a feature widely supported in vendor NetFlow/IPFIX > implementations?). > > Exporting AS information is wire-format agnostic feature, if it's > supported or not, it can equally be injected into sFlow, NetflowV5 > (src and dst only), NetflowV9 and IPFIX. The cost is that you need to > program in FIB entries the information, so that the information > becomes available at look-up time for record creation. > > In OP's case (IOS-XR) this means enabling 'attribute-download' for > BGP, and I believe IOS-XR will never download any other asn but src > and dst, therefore full information cannot be injected into any > emitted wire-format. > -- > ++ytti >
