Well CEF that is Cisco Express Forwarding is an advanced Layer 3 IP switching technology, so CEF is a method of performing Layer 3 switching. Layer 3 switching can be performed using both hardware and software. CEF is the software method of performing it. CEF is a better method as it less CPU intensive, so mor e of CPU can be dedicated to other services.
I was under the (perhaps mistaken) impression from my recent exposure to BCMSN material that the wire speed performance in cisco multilayer switches running IOS is due to specific hardware, such that a 'normal' IP packet that would usually require router processing could be switched between different VLANs using hardware (sending the oddball packets to the L3 engine). The book calls this CEF.
In other words, cisco L3/L4 switches implement CEF caching for routine IP traffic in hardware whereas routers implement it in software (and probably in varying ways due to the different architecture of each routing platform - a 7500 has different plumbing than a 2500).
L3 switching refers to hardware based processing of L3 packets (not necessarily CEF). However, there are different methods for building and maintaining the data structures used to make the forwarding decisions. CEF and Process switching are two of those methods. Please take a look at the following document which compares and discusses the characteristics of CEF, as well as, Process switching (and others).
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...