Unfortunately it doesn't mention how many routing entries it can handle, so I suspect it's got to do with how much memory you have installed as a previous member pointed out earlier.

Let's now look at it another way, with CEF enabled how many routing entries can the 7206VXR handle, surely there must be a limit as CEF directly utilises the underlying hardware caching system.

You're confusing CEF and dCEF. CEF is "just" a way of building a forwarding/adjacency table with packets being forwarded in the fast (interrupt) path. They're still processed by the CPU but its done in a different spot. (Grossly oversimplified, I know!)

dCEF is distributed CEF; where the forwarding/adjacency information is pushed out to intelligent line-cards which can then make forwarding decisions themselves without involving the RP. In this case the line cards need to have enough resources to store a full forwarding/adjacency table.

To answer your question: as far as I know, the NPE-G1 is just a software forwarding engine. The interfaces can forward packets rather quickly but they don't make routing decisions and thus it isn't "dCEF". The CPU builds a CEF table in RAM and routes the packets itself.

(If this were a cisco 7500-type setup with VIP modules which ran dCEF then yup, you'd also have to worry about the capabilities of the VIP.)

Thanks adrian!!