A Virtual Local Area Network (VLAN) is a formidable networking technology. As a network expands, new technologies such as a VLAN can accommodate this expansion in a cost effective and performance-geared manner. As a company grows and develops, physical network changes can occur quickly; a VLAN can help compensate for these changes and maintain an efficient network.
A VLAN is becoming an increasingly popular solution for LAN segmenting. The principles of VLAN technology provide an impressive amount of features, policies, and yet retain some simple foundations in terms of design and architecture. With an expanding company network, the flexibility of a ...view middle of the document...
In addition to compatibility with layer 2 style MAC address assignments, a layer 3 switch can provide assignment based on ip address. It is also capable of router like functions, so if a user on one VLAN needs to communicate with a user on another, a layer 3 switch would be more than ideal (Sridhar, 2010).
While the technology for a VLAN is stored in the switch hardware, the type of VLAN and membership must be initialized and configured by a network administrator. For the company scenario, the membership type in place will be a dynamic scheme. With a dynamic VLAN, membership is recognized by a policy server. The VLAN policy server will automatically assign ports based on the MAC or IP addresses of the network nodes. This setup is simpler and more expansive than a static scheme.
Within the switch trunking will be used to great effect. Trunking removes the need for multiple physical network adaptors and more infrastructures. With trunking, a single network adaptor can act as multiple virtual adaptors. The result is high performance, low cost, and an extremely flexible solution. A high end layer 3 switch trunks with a built in routing module. This routing module can complement the high-end L3 switch by providing additional isolated routed zones for departments within the company (Ou, 2003). This will allow each department to be sectioned into different broadcast domains with much less broadband consumption.
VLAN trunking also lends itself to an enhanced security policy for the company. With VLAN trunking, a nearly unlimited number of virtual network connections are provided at a lower cost and higher performance (Sridhar, 2010). NetScreen firewalls can block dangerous traffic within and between zones, since VLAN trunking further allows you to separate devices by security level and function, a firewall makes perfect sense (Juniper Networks, 1999-2011).
Residing at layer 2 is the “control center” of a VLAN, the VLAN trunk protocol (VTP). The purpose of this protocol is to provide a means to add, delete, and rename VLANs. In a switched network, VTP reduces the amount of network administration required. At the policy management server a VLAN edit will be carried through all trunked switches in the domain. This means VLANs can be added, deleted, or...