Network switch, which is used to enhance the capacity of the network by linking multiple electronic devices, is an essential component of a computer network. It is basically an electronic device, which processes and communicates information at different layers of the Open Systems Interconnection model. Network switches were introduced in the market in early 1990s for the first time.
Network switch receives data from a electronic device, connected to it. After receiving the data, it validates the data and routes it to another electronic device, for which the data was generated. Validation of the data by the network switch includes examining the source and target hardware addresses against a predefined table of network addresses. Thus the invalid messages are discarded and not allowed to increase the traffic on the network route. Depending on the area covered by the local area network, different types of switches are used. Typical small area networks, such as small office or home office networks use a single switch. Multiple interconnected switches are used in medium to large area networks. Commercial network switches feature built-in interfaces, through which different types of networks could be connected.
Some network switches, which are capable of operating at different network layers, are known as multilayer switches. Different types of switches operate at different layers. Though the multilayer switches may operate at different communication layers, most of them share some common features, like Ethernet interface.
Layer 1 Switch
Network hub, an example of layer 1 switches, is the simplest network switch, which operates at the lowest layer, i.e. layer 1. It does not examine the received data packets. All the data packets, received by it, are forwarded to all nodes, except itself. Since each data packet is transmitted to every node, data packet collisions occur frequently, which hamper the communication process. This is the main drawback of network hubs. But this limitation could be useful in some particular applications, in which the same message is transmitted to all network nodes.
Layer 2 Switch
The most common example of layer 2 switch is Network Bridge, which operates at the data link layer. It interconnects the electronic devices with known hardware addresses. In some specific applications, such as storage area networks, network bridges are widely used due to their superior performance. Many switches of this type use spanning tree protocol, which employs loop free topology to prevent bridge loop formation. In this topology, only one active path exists between two nodes.
Layer 3 Switch
As the name indicates, this switch operates at layer 3 of OSI model. A typical layer 3 switch is quite similar to a router. The most common feature of this type of switch is IP Multicast method, using which data frames could be sent to multiple nodes in a single transmission.
Layer 4 Switch
These types of switches come with network address translation capability. Firewalls, IP security gateways, which should be configured with the assistance from a computer support provider, are examples of layer 4 switches.
Layer 7 Switch
Layer 7 switches are capable of distributing loads, based on some specific tools, like Uniform Resource Locator.
There are numerous network switches in the market. All manufacturers provide extensive tech support for switch problems. One of the most popular network switches is Dell PowerConnect. If the user faces any problem while installing or using PowerConnect, help from a Dell support provider should be taken.