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New Member

Recommendation for setting up VLANs

I have inherited a legacy mess of a network in my current job and am looking to redesign the LAN infrastructure. I will be replacing most LAN hardware with Cisco switches over the next few months using mostly Catalyst 4xxx series equipment. The current setup is a flat network design with no VLANs and two internal subnets combined into an ugly mess. The total count is about 400 ports and the backbone router is a 3662 which provides WAN frame connection as well.

Anyways, I am looking for suggestions on configuration to segment users/departments/traffic for broadcast domain reduction and resource security reasons. I would also appreciate any recommendations on good reading materials for setup and maintanence of VLANs.

Thanks in advance.


Re: Recommendation for setting up VLANs


You can segment you network with vlans depending upon your office layout.

There are many ways,

like may be per floor, per department, per protocol, like ip, ipx or per technology. or for example servers on one vlan and clients per floor. in different vlan . anywayy ou want to separate the network from the other enviorment-

here is the good URL for your ref.

hope this helps

New Member

Re: Recommendation for setting up VLANs

I hope that you have NOT started your project yet????? Anyway, one BIG recommendation that I would give you on segmenting your network using VLAN on the Cat4K is that you do NOT use VLAN1 for any of your normal enterprise traffic. By enterprise I mean user/server/PC/printer etc traffic. Use VLAN1 ONLY for switch/router management. The reason behind this is that once you've subnetted your network and you want to improve routing performance by using a L3 module on the Cat4K, routing on VLAN1 is "process switch" ONLY!!!! That is 10 times slower than fast switch is is on automatically on other VLANs.

For security and other features on Cat4K, let me know if you planned to use this L3 module or not at

New Member

Re: Recommendation for setting up VLANs

Keep the number of nodes in the vlan to under 250.

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