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mheusinger Tue, 01/16/2007 - 08:33
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Hi,


there is no definite answer to your question. The NPE-G1 capability to handle routes will be limited by the installed memory. Depending on the routing protocol, IOS version and other features being enabled this may vary because the available memory varies.


Be assured that f.e. the internet today with more than 200000 networks does not pose any problem. For a working example with more than 500 MB BGP table please login to

telnet://route-views.oregon-ix.net


Hope this helps! Please use the rating system.


Regards, Martin

770801tvdhaar Tue, 01/16/2007 - 08:53
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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.

adrian.chadd Tue, 01/16/2007 - 19:15
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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.)

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