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QPPB in MPLS VPN

Quick link for the attention-challenged: QPPB works in MPLS VPNs (with a few limitations).

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.

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4 comments:

  1. "Quick link for the attention-challenged"

    I'll have you know, sir, that the politically-correct term for this disability is "differently attentive." In the future, please show more compassion for those of us who--ooh look, a kitty!

  2. ROFL :-D Thank you, you've made my day 8-)

    OTOH, you can't imagine how hard it is to properly address these difficult areas when English is not your native language O:-)

  3. Ivan, this is an old post, but, do you have any examples or just thoughts on MPLS Inter-AS Option C. Does it really saves all the operational work? Is it really used in practice?

  4. Inter-AS Option C is used in practice and is definitely a better option than (A). Whether you prefer (B) or (C) depends on what you want to ASBR routers to do and how much you trust the other AS.

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