It's important to note that this is pushing the limits of x86 kernel networking. All commercial and enterprise routers (like the ones in your colo) use an ASIC for transit traffic. Management traffic usually gets routed by the ASIC to a GP processor like an x86 or similar.

> On a 10 Gbps link it is possible to pass packets at a rate of 14.88 Mpps. At that rate that we have just 67.2ns per packet. Also you have to keep in mind that an L3 cache hit, yes that is a “hit” and not a miss, costs us something on the order of 12 nanoseconds.

It's for this reason that transit traffic is handled by the ASIC, where rules for the session have already been established, and it can just match and forward/drop/reject. The management packets (of which there are far fewer, but they require a great deal more processing) are handed off to the general purpose (GP) processor. In Junipers they do use x86; I'm not sure what Cisco uses.