Hi, what you said is almost correct ... Proccess/Fast/Distributed/Packet switching are all layer 2 functions.. >From the CCO Fast switching allows higher throughput by switching a packet using a cache created by the initial packet sent to a particular destination. "this is all done at layer 2" Destination addresses are stored in the high-speed (switching)cache to expedite forwarding. Routers offer better packet-transfer performance when fast switching is enabled. Fast switching is enabled by default on all interfaces that support fast switching. layer 3 switching differs from this by having the first packet sent to the router (which routes the packet to the correct outgoing port ..this is a more efficent way of finding destinations than switching ,...switching envolves looking at a singular table or flooding -leaveing out CEF on purpose-) it then stores this info in the cache and all following/Same destination packets are switched using info in the cache... i have read somewhere that is 4-9 times faster to switch a packet than to route one so this gives us an increase in throughput via "intelligent switching"-my own term please don`t quote me on the 4-9 times bit ...but it IS defenatly faster to switch .. HTH steve >From: "dovelet" >Reply-To: "dovelet" >To: [EMAIL PROTECTED] >Subject: Question about fast switching and layer 3 switching [7:13941] >Date: Fri, 27 Jul 2001 06:08:46 -0400 > >Hi all, > >I have a question and I hope someone can help me. As I know, Cisco router >support several switching method, e.g. process switching, fast switching >etc. In some document, it state that fast switching is when the 1st packet >goes into a router, it will go through the routing process, the other >packets with the same source and destination address will go through the >switching process. As I know, the layer 3 switching router is doing the >same >job. Then, what is the different between a layer3 switching router and a >router in fast switching? > >Regards, >dovelet _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=13962&t=13962 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]