2 Replies Latest reply: Mar 10, 2012 6:40 AM by Earl Granger RSS

    L3 design help

    Earl Granger

      I have a design question. I have 2 L3 Switches(3560) and they will be connected to a 4500 switch running OSPF. I need the 2 switches connected via fiber and then back to the 4500 switch. These 2 3560s will have APs, video and users. The 4500 has L2 services such as vlans. I want the users to only have normal services such as internet connection. I need to route between vlans. What would be the best design?

        • 1. Re: L3 design help
          Paul Stewart  -  CCIE Security

          I am assuming the 4500 is connecting upstream to other L3 devices or you wouldn't really need ospf. With only what you have listed, you can't really go too wrong. I would try to physically connect everything to what is central to the use case. So if 90% of your traffic goes to VLAN 10 on the second 3560 and does not require routing the majority of the time, you might make sure you physically connect everything to this switch. If routing is central to everything, try to get a physical connection to the 4500 for everything.


          If you can connect via fiber the way you indicated:




          You most likely can physically wire like this as well:




          Most fiber plants have extra dark fiber that can be used with fiber jumpers (just a fiber patch cable) between different runs the patch panels.


          Also, it is best if you build some redundancy and let stp block the least use paths per vlan. Again, not a lot of information to go on. If you have specific concerns, please post back.

          • 2. Re: L3 design help
            Earl Granger

            There would be essentially 3 vlans.  There would be 1 for video, 1 for aps, and 1 for users.  So, should I let the 4500 route between vlans?  Also, I dont want the users to have any access to the internal network.