当众多厂商纷纷推出交换式以太网和令牌环产品时,他们就用是否具有“虚拟LAN(VLAN)”功能来区分各自的产品。尽管VLAN的功能是诱人的,但网络管理员在评估交换式产品时必须小心,一定要弄清楚VLAN能做什么,不能做什么,以及这些权衡对网络的影响如何。 VLAN允许管理员在逻辑组的基础上创建工作组,逻辑组与集线器的物理配置不需有任何直接关系。一个VLAN基本上就是一组相关的地址—— When many vendors have introduced switched Ethernet and Token Ring products, they use the “virtual LAN (VLAN)” function to distinguish their products. While VLAN functionality is tempting, network managers must be careful when evaluating swap products, making sure to understand what VLANs can and can not do and how those trade-offs affect the network. VLANs allow administrators to create workgroups based on logical groups without any direct relationship to the physical configuration of the hubs. A VLAN is basically a group of related addresses -