70 PCS, now has three switch, China 3 LS 3600 V2, 28 at the mouth of the current broken one, now if I buy a same back switches can be used? Still need to reconfigure the room directly connect outside network, light even the cat came in routing, not into the campus Intranet, baidu, what of VLAN and so on, this need only a network segment, can be controlled, the students went to the network, do not need communication each other, as long as the function of the teacher control, give them open a web page, issued documents and so on, also need to use layer 3 switches? Or buy some two layer directly connected to the router, the configured IP binding MAC??????? This room every year the whole green arrogant class, the teacher online marking network (7 days), and students learn the office line,