routing help

[TheGuyB4Me]

I recently got put in charge of laying the switches out for a new fiber project. We need to connect several different buildings on the LAN. There will be a lot of traffic generated and I would like to put l3 switches at each building. However I want to be able to use the same ip range throughout the LAN and use the same default gateway. We have laptops/iPads that roam building to building.

Is it possible to do this without subnetting the client machines behind each switch so laptops can roam with using layer 3 routing. I've used packet tracer with 3560 to try to lay out a design. Any help would be appreciated.

[tobyarnett]

Simply put if you are laying fiber to all your sites and you are using a switch to connect them, then you should configure two of the switches as your primary and secondary devices. Configure your L2 and L3 vlan on each. Use HSRP on those two switches for dynamic fail over and ensure your client devices use the HSRP IP for their gateway.

Then just use trucking and L2 VLAN's on all your other switches. This will keep all devices in that vlan on the same network.

If you have an L3 link between all devices then you won't be able to use the same subnet on for all your switches.

Toby


Sent from Cisco Technical Support Android App

[Richard Burts]

George

Some of the objectives that you describe seem to be mutually contradictory. You talk about having a layer 3 switdh for each building. Many people design their networks this way and it may provide a more scalable design, providing separation of broadcast domain per building.

But you also describe having the same IP range in all buildings. This suggests having layer 2 switches in each building and a single router for the network. This is a very valid implementation but significantly different from the first alternative.

You need to consider the alternatives and determine which is the most important to you. Then we can advise you on how to implement that alternative.

HTH

Rick