[f-nsp] Adding route-distinguisher and VRF target to a route in an export policy on an MLX

[David Ball]

  I know this'll sound strange, but work with me....

  I have an existing non-Foundry network, part of which provides
internet services to customers, and said internet service is provided
via the use of 1 large VRF.  I'm exploring the option of adding an MLX
to this network, but the MLX can't hold a global table in a VRF (a
restriction I still struggle with), so I'm having to explore some
options.  I know I could use a VRF on the MLX and just reduce the
number of routes I export to it from the upstream devices...the only
real downside is that any BGP customers requiring a full table will
need to multihop to the nearest full-routes devices (meaning 4 BGP
sessions, if redundancy is desired).

  The other option I'm wondering about, and it's still not solidified
in my head yet (perhaps for good reason), is the idea of applying an
appropriate VRF target and route-distinguisher to an 'internet' route
leaving the MLX before it arrives at the upstream router, such that it
looks to belong to the appropriate internet VRF once the advertisement
reaches the upstream router.  Similarly, those attributes would need
to be stripped off on ingress.  Nothing is jumping out at me from the
manuals pertaining to this possibility, but, crazy though it sounds, I
wondered if anyone had run across it previously.

  Thanks for any insight you might be able to provide.

David