VLAN
Student Name
IT 242
January 30, 2011

VLAN
Virtual Local Area Network (VLAN) is one of the latest network technologies that has been created in the past several years. The technology for VLAN is growing rapidly as well as the costs of the equipment used to implement the secure network that is often considered expensive. Virtual Local Area Networks were born out of the need for a cost effective network that did not compromise the need for high security and performance so the VLAN met all the requirements for the special network (Regan, 2004).
The VLAN offers a great deal of functionality for any network as it was created to separated the network into separate broadcast while still allowing each network to still function in the different locations. An example of this process is if a business has different departments such as Operations, Sales, and Human Resources. The VLANs are implements specifically for each department making it an individual network within the business.
When implementing a VLAN, it is important to know that to create the VLAN there is a need for layer 2 switch. One common misconception regarding VLANs is that there is a need to install separate software in order to implement the VLAN within the network. The fact is VLANs need special hardware that is built into the switch, which implements a separate network of the main network.
Depending on what the network’s security policies and infrastructure, VLANs assignment can be implemented using one of two different methods, Static or Dynamic memberships. A Static VLAN is where the Network Administrator configures statically the ports of the VLAN. The VLAN memberships are assigned on a port-by-port basis on the switch ports. The Dynamic VLAN has a VLAN management policy server that automatically assigns the ports of VLAN since it uses the MAC address of the nodes in order to create the right assignment. Some of the benefits when implementing a VLAN include Virtual Group Model, Enhanced Network Security, Reduction of Routing for Broadcasting, and Improved Administration Efficiency.
Access links connect hosts and trunk links connect to the backbone of the network. It is important to know the login that is specific to the types of links and interfaces used for the operations of access and trunk links. VLANs logically groups the independent LAN stations to the physical locations using the bridged LAN infrastructure.
VLAN Trunk Protocol (VTP) generally is used and provides automatic definitions between the core switch and the distribution switches. This means the core switch needs to be defined once at the core switch allowing the VLAN definition automatically propagate to all the network’s distribution switches. After the VLAN definition has been propagated to the distribution switch, the assigning of ports to the VLAN is then performed.
The VLAN Trunk Protocol (VTP) is a Layer 2 protocol for messaging that can add, remove, or modify VLANs on the network. VTP is designed to provide automatic distribution of definitions at the core switch to the distribution switches. This feature allows the client to define once the VLANs at the core switch and have the VLAN definition automatically recreate to all of the other distribution switches for the network. After the VLAN definition has been completed, it is then possible to assign ports to the VLAN (Regan, 2004). There are many benefits of a VLAN. The main benefit is that the physical boundary is removed with careful planning during the implementation of the installation.
The Enumeration of a VLAN Implementation Plan involves the following: * To define the LANs membership * Determine what is the best method for communicating the VLANs information of the members through the multiple switches * Differentiating and Creating the Workgroups * The Automatic Configuration * The Mapping between Virtual connectivity and Physical connectivity * Ensure the configuration of consistency * The traffic analysis and control with the VLAN

Using all of the factors listed above, either a network expert or engineer is able to find the best method to use for the implementation of a VLAN that is based on the infrastructure of the company desired grouped network.

Reference:
Regan, P. (2004). Wide Area Networks