And now for the long story: A while ago I’ve noticed that my LinkedIn friend Joe Cozzupoli changed his status to something like “trying to get QPPB to work in MPLS VPN environment”. I immediately got in touch with him and he was kind enough to send me working configurations; not just for the basic setup, but also for Inter-AS Option A, B and C labs.
Knowing that QPPB relies on CEF, I doubted it would work as well on VRF interfaces as it does in pure IP environments, so I decided to do a few tests of my own, which took quite a while (not the tests, but finding the time to do them). Not surprisingly, as the outbound (PE-to-CE) packets are not CEF switched, you cannot use QPPB on them; it only works on the inbound (CE-to-PE) traffic. Furthermore, you cannot use extended communities in QPPB route maps.
Even when I’d got all the details figured out, it took weeks before the final article appeared in CT3 wiki; one of the challenges was finding a good use case. We really liked the idea of using QPPB to limit the traffic from customer sites to VPN common services; if you have any other really good usage scenario, please let me know.