Network Design Question

[rudedm]

I am hoping for some feedback on a network design question. Here are some details of the situation. We have 8 switch uplinks to the core. We have 40 servers connected to three seperate switchs (1-2970, 2-2950). We currently are using a 12 port 3550G for a core and are out of ports. I have been looking into a new core and thought about a 4507 that could then handle both the core and the server links. A vendor of ours recommended a 24-port 3750G for a core and said the other switches are fine. I was just hoping for some input on which path I should pursue. Thanks in advance for the help.

[dcrown]

I preferr the "just hang switches and routers off the core" method. Your 2900 will do the job of a server access layer. My biggest reason for doing this is modularity and growth. 2900 ports are much more in expensive than 4500 port, and it makes things like redundancy eaier to grow into. I also like to stick the switch my servers use right in the rack for added ease of cabling.

[mchoo2005]

If you only need Gig copper in the core, then 3750G-24TS should do fine, and they can be stacked for future growth. In fact, in this case, using 3750Gs would probably give you better performance than 4507. Reason being, 4500 series switches only give you 6Gbps full duplex per slot. Therefore, if you plug in any linecards with more than 6x Gig ports, you will not get wire-rate switching. In a case of 24-port Gig linecard, there would be 4:1 over-subscription, which is not a good thing for Core switches. Bear in mind that Cat 4500s have centralised switching architecture. This means, switching from one port to another, ON THE SAME BLADE, will require the frame to travel across the backplane, rather than switches locally on the blade.

HTH