Theoreticl Switch/Router Question

[anthonym]

We have one site, on one floor, in one building, with around 150 Staff.

Due to the way we have grown, we have three sets of Cat5 cabling, set 1 terminates in the main computer room, sets two and three terminate in wireing closets.

Set 1: ~100 devices.

Set 2: ~50 Devices.

Set 3: ~ 30 devices.

These cabinets are joined by fibre, which currently terminates in a CE500-12TC switch. The switches in the other stacks are 3Com 4400SE (unmanaged no VLAN) and CE50024-TT switches depending on the age of the stack.

The servers also are connected to the 12TC.

My questions are, Is this a sensible layout? Would it make sense to have the three sets as different subnets with the fibre terminated in a router? Would it improve performance? Would it make sense to Swap the 4400SEs for more 24TTs and set up VLANs? Would would be the performance benifits?

[mheusinger]

Hi,

first question: what are the problems you try to address? If it is not broken, do not fix it.

You are talking about performance gain ... what causes a lack of performance (if so)?

Please provide more info, a redesign can only succeed based on the requirements and restrictions known.

Regards, Martin

[anthonym]

There are no problems I am trying to address, I am simply trying to discover the best way of configuring things, out of interest.

No changes re going to be made, as the system is running fine as it is.

IFF I was to rebuild this network, what would be the optimum solution?

[gpulos]

unless you have broadcast domain, collision domain traffic issues/congestion or security concerns, the best layout would be to keep just one vlan for all hosts. (with only 150 hosts, a single vlan will be just fine)

use switch Stacking where applicable and if you cannot use switch stacking, then connect those switches directly to a 'core' or main switch. (the ce500 currently)

the main thing to keep in mind when designing a switching environment is traffic aggregation. if you have a 100MB port that connects to a switch that is stacked or daisy chained to multiple switches, (well above 100MB aggregated traffic), then you would want to allieviate that oversubscribed 100MB port if possible by removing some of the stacked/daisy chained switches and connecting them directly to their own port at the core.

does this make sense? if not, see this link for more info:

http://www.cisco.com/univercd/cc/td/doc/solution/dci_srnd.pdf

this document describes much bigger environments than yours but the concepts of the network design are what you should focus on.

[anthonym]

Thanks for the reply.

With respect to the stacking. The 4400s are stacked using apropriate modules, and connected into the cored with 1GB (either Copper or fibre depending on physical placemnt) the CE500s don't have the ability to stack, so which is better, direct connections to the core, or daisy chain, with one or more connections to the core?