At 12:45 PM +0000 2/26/03, DeVoe, Charles (PKI) wrote: >OK, let me try this again. I am trying to figure out the difference between >conventional layer 3 routing and layer 3 switching. A little background. I >am currently working towards my CCNA (have been for about 3 years). At any >rate, everything I read and look at says that switching/bridging is a layer >2 function, routing is a layer 3 function. > >Either I don't have a good grasp of the OSI model, switching, routing, VLANs >or all of the above. >
No, it's not you. It's that Cisco marketing (in fairness, in response to competitive marketdroids then at Cabletron, Synoptics, etc.) doesn't care to apply a knowledge of this model and likes the industry flavor of "switch fast router slow." Relay destination lookup time simply is not a major problem in router design. At one point, it was, but as router implementers started using faster lookup approaches, the lookup time pales into insignificance compared to things like traffic shaping/policing, accounting, etc. Abraham Lincoln once said, "If you call a horse's tail a leg, how many legs does a horse have?" The audience mumbled "five," and he replied "No. Calling a tail a leg does not make it one." Calling a nonspecific family of routing implementation techniques "L3 switching" doesn't make them anything other than routing. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=63882&t=63728 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
