Hi Frank, I think the best description for Layer 3 Switching is "Route once - Switch many". The first time a packet in a particular "flow" passes through, a routing function will be used (on a different card, or even in a different device). But to speed up the processing of any further packets in that flow, a cache is created in the switch to remember this flow. The next time a packet comes through which matches this flow it will be switched without using the router functionality, therefore speeding things up. The definition of a flow can differ depending on configuration. For instance, normally a flow may be any packet to a particular destination, but if , for example, an extended access list is configured, the criteria for the flow may tighten up i.e. to be considered part of a flow, the source and destination are compared. Inter-VLAN routing means a packet gets routed every time. Regards, Gaz ""frank"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > What does the following mean ?it's cut from a description of WS-X4232-L3 on > cisco website. > > > The Catalyst 4003 and 4006 Layer 3 Services module provides interVLAN > routing for the Catalyst 4000 family switch and provides Layer 3 switching > between the Gigabit Ethernet interfaces. > > "John Hardman" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Hi > > > > OK I'll bite... > > > > Yes there is a difference. It gets a little convoluted, but there is a > > difference. > > > > L3 switching: Think of a L3 switch as a multi port router that operates at > > wire speed. The 2948G-L3 is an example. It is just a 50 port Ethernet > > router. So L3 switching is routing traffic at wire speeds. You could use > one > > of these to route between VLANs, or route between networks. > > > > Inter-VLAN routing: This is a technique, technology that is only used to > > route traffic from one VLAN to other VLAN(s). It generally takes place at > > wire speeds inside a Cat switch with a L3 switch option, but is often see > > with routers that do not work at wire speeds. > > > > So the bottom line... think of a L3 switch as a device, and Inter-VLAN > > routing as a technology. > > > > HTH > > -- > > John Hardman CCNP MCSE > > > > > > ""frank"" wrote in message > > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > Any difference? > > > > > > "frank" wrote in message > > > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > > Thanks, > > > > > > > > > > > > Frank > > > > FAQ, list archives, and subscription info: > > > http://www.groupstudy.com/list/cisco.html > > > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > > FAQ, list archives, and subscription info: > > http://www.groupstudy.com/list/cisco.html > > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=6104&t=6104 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
