it allows you to seperate trafic, say like starbucks, they have free wireless, and they have there own network, vlan lets you sererate them so people on the free one cant mess around on your network.
So, it separates bandwidth, then? Now, HOW would go about making a VLAN? What's the min. & max amount of hosts i could turn into a VLAN? What can i do if a LAN has routers + switches?
VLANs are flexible, depending on your switch. How you configure it and what your switch allows you to do can do seperate things. At our schools, we have 2 VLANS. Admin, for the administrators, and Curriculum for the students and teachers. Among other things, admin machines can access the curriculum domain, but not the other way around.
You will need to set up a trunk that connects the switch to a router with a patch cable which will route all the vlan traffic. This will need to be configured on both the switch and router. A trunk will send traffic from all the vlan to and from the trunk port. This port can be any port you assign. On the router you can configure ACL’s to allow or deny traffic to and from the different vlans.
What networking equipment are you running?