ng_netgraph and BGP

[William Waites]

I run a small network composed of even smaller networks each
encapsulated in an autonomous system. I'd like to do traffic
accounting using netflow aggregated by ASN. My border routers run
FreeBSD and BIRD.

Right now, and this is mentioned in ng_netflow(4), we do not fill in
the source and destination ASN because there is no information to get
this from the routing daemon's RIB. Probably if we come up with such a
way it should be generic so it could be used by Quagga, BIRD or
OpenBGPD.

I've done a little bit of thinking about how this could be done, and
come up with two main strategies:

  1. A new kind of netgraph node inserted before ng_netflow knows how
     to query the routing daemon and decorates the packet with the
     result, which ng_netflow then puts into the flow packet if
     present. This entails either a copy (tee) or putting the lookup
     in the data path which may be suboptimal.

  2. A new hook added to the ng_netflow node that allows it to query
     the routing daemon through a different new kind of netgraph
     node. This is probably better but may be slightly more
     complicated to implement.

Is anyone working on this or has given this though? I wasn't able to
find much by searching the list archives. It may be that I will soon
have some students that I can set on this task but would not like to
unnecessarily duplicate effort.

Cheers,
-w

--
William Waites <wwaites at tardis.ed.ac.uk>  |  School of Informatics
   http://tardis.ed.ac.uk/~wwaites/       | University of Edinburgh
       http://www.hubs.net.uk/            |      HUBS AS60241

The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 801 bytes
Desc: not available
URL: <http://lists.freebsd.org/pipermail/freebsd-net/attachments/20150401/e5591198/attachment.sig>