Han Chuan Alex Ang wrote: > > hi, I am trying to have a clearer picture of the layer 3 > switching > > concept. > > Assuming that I have a Core Catalyst 6 series switch with layer > 3 > > switching capabilities, I have a Access layer switch connected > to the > > core with two port label Vlan 1 subnet 1 and Vlan 2 subnet 2, > > when frames is sent from from Vlan 1 to Vlan 2 on the same > Access > > switch, my understanding is that for layer 3 switching , it > will > > evoke a route one and switch the rest concept ,
Layer 3 switching just means routing. What you're talking about is an advanced feature of some switches whereby the L3 core switch can tell the L2 access switch how to encapsulate and forward the packets for this flow on its own in the future. This is sometimes called distributed switching or multi-layer switching, although both those terms get used in other ways too. Many Cisco switches don't support this, but some do. Both the core and the access switch would have to support this advanced feature for it to work. The Catalyst 6000 does support it. The L3 core switch has a route processor in it. It acts as a router. It talks to the L2 access switch's switching engine with a protocol such as Cisco's Multilayer Switching Protocol (MLSP) to let the L2 switch know how to handle the packets in the future. Architecturally it's no different than a router that has a route processor and a forwarding engine, except that now the jobs are being done in two boxes. It's not accurate to equate this behavior with L3 switching. It's more accuate to say this behavior is one feature of some advanced L3 switches. Notice that it requires an additional protocol. It also requires quite a few non-default configuration commands. Priscilla > my question is > that, > > after the first route , if no Access list has been created, > will the > > the Access switch be smart enough to perform internal > > switching, that is , frame direct from Vlan 1 to Vlan 2 > internally > > within the Access switch. If the answer is no, Are there > switches on > > the market that is routing by this concept, please advice , > > thanks to all the guys who have tried to entertain all my > questions > > > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=63317&t=63304 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
