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'Good form' rules in designing networks

Are there some simple rules (as best practice) witch we must follow in designing LAN?

I debated with a customer’s specialist how to build LAN in his new edifice.

There is a building with the next planned desktop distribution per floor: 50, 40, 130, 50 and about 10 various servers. Customer is a bank.

Client is sure the next structure will satisfy his requirements: as core will be used 3750G-12S + 3750G-48TS (two for each for resilience). On floors there will be groups of two 3560G-48. Each group will be connected with 2 ports Etherchannel to “core”. 3560G in group will be interconnected with CAB-SFP-50CM (Catalyst 3560 SFP Interconnect Cable).

I am sure this is wrong way. But I have only intuition and theoretical arguments.

At first I think the 48:1 oversubscription on wiring closet is too much. I saw somewhere the recommended value is up to 20:1.

Next: for LAN with 250-500 workplaces Cisco recommend using Catalyst 4500 as core. 4500 Supervisors had at least 64Gbps and 48Mpps (Sup-II) and I think it is may be not enough for him. Client solution has 32GB bandwidth (3750 StackWise bus). But may be he’s right? For his 8GB all uplinks speed this is enough?

Has anybody any ideas? May be offer me any useful links, where such questions are discussed.

  • Getting Started with LANs

Re: 'Good form' rules in designing networks

Take a look at the design guides. They are guide, not hard and fast rules.

HTH and please rate.