Virtual LANs

Introduction

Another important advantage of Ethernet switches is the ability to create Virtual Local Area Networks (VLANs). A virtual LAN is a logical subset of the LAN configured by a network administrator. The traffic for different VLANs remains segregated resulting in increased efficiency of network operation. This is useful in many cases, for example, to keep the traffic for different departments in an organization separate. The traffic of the Accounts Department, for instance, may want to be kept separate from that of Network Operations, Human Resources and so on. A virtual LAN is hence a set of ports attached to one or more Ethernet switches. A switch can support several VLANs and it runs one MAC learning algorithm for ...