Re: VLAN
hi guys,
Switched LANs enable us to create VLANs. A VLAN does not completely fit the earlier definition of a LAN as being limited in geographical scope; with a VLAN, geography has no meaning. A VLAN is a logically independent network, and multiple VLANs can coexist on an individual physical switch. VLANs are used extensively in campus networks, allowing users to be part of the same broadcast domain while being physically separated, on different floors of a building, or in different buildings on a campus. This is because a VLAN is defined by software rather than by hardware and physical location. The major difference is that VLANs can restrict the broadcast and collision domain to members of a particular VLAN. .
A switched VLAN is a high-speed, low-latency broadcast group that unites an arbitrary collection of endstations on multiple LAN segments. Switched virtual networking eliminates the bottlenecks normally associated with a physical LAN topology by creating high-speed switched connections between endstations on different LAN segments. Users who want to belong to a particular broadcast domain do not have to be physically located on that LAN segment.
VLANs provide a software-based, value-added function by enabling the creation of a virtual broadcast domain, a shared LAN segment within a switched environment. Switching latencies on VLANs are typically one-tenth those of fast routers. However, routers are still required for inter-VLAN communications.