Ok all I have a question on this subject. I know routing takes place at the network layer, and switching takes place at the data link layer because it works based on physical addresses. So how do we get route switching? I've just started my CCNP and we were learning about different cache methods to speed up performance, is this how route switching is done, is the routing calculation be performed on a per packet basis? I was reading that by default, Cisco routers only perform a routing calculation on the first packet for a destination network and then on less the no route-cache option is set all the rest of the packets are really only "switched" to the correct interface. Am I missing something? I would invision that a router would by default perform a lookup for each connection sequence. does layer 3 routing not do a look up for each sequence of packet? Does is look at an address and use an "old" pre say route that was cached in memory? If some one can give a good explanation I would greatly appreciate it.
Thanks, Steve Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=74788&t=74788 -------------------------------------------------- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html

