Accelerated CEF (aCEF)—CEF is distributed across multiple Layer 3 forwarding engines, typically located on Catalyst 6500 line cards. These engines do not have the capability to store and use the entire FIB, so only a portion of the FIB is downloaded to them at any time. This functions as an FIB “cache,” containing entries that are likely to be used again. If FIB entries are not found in the cache, requests are sent to the Layer 3 engine for more FIB information. The net result is that CEF is accelerated on the line cards, but not necessarily at a sustained wire-speed rate.
Distributed CEF (dCEF)—CEF can be distributed completely among multiple Layer 3 forwarding engines for even greater performance. Because the FIB is self-contained for complete Layer 3 forwarding, it can be replicated across any number of independent Layer 3 forwarding engines. The Catalyst 6500 has line cards that support dCEF, each with its own FIB table and forwarding engine. A central Layer 3 engine (the MSFC3, for example) maintains the routing table and generates the FIB, which is then dynamically downloaded in full to each of the line cards.
thanks but i asked because i read this from book and i need more explaintion
what dose line card mean is it interface ?
and what is the portion of FIB belong it ?
and the FIB portion in the line card does it depends on mac teble for this laine card ?
if some body has an article for complete this i will be thankful
for your first question : No it does not mean interface, it means supervisor engine like supervisor 720
second question: your answer is in the text -> containing entries that are likely to be used again
Third question: as I said in previous answer line card means supervisor engine and does not have mac address.