• A network switch is a device that connects network segments.computer cables image by timur1970 from Fotolia.com
  
  A computer network is a collection of computers and other hardware devices and software programs that are interconnected to share resources and information. A network switch is a device that connects network segments or hardware peripherals (such as a scanner, printer or computer) to the network and allow it to effectively communicate with other nodes. A switch manages the exchange of data between two points over a network, and comes in two basic types: unmanaged and managed.
  
  

Configuration

• Unmanaged switches cannot be configured to suit the needs of a network. They are simply connected to a network to facilitate communication. Managed switches can be fully configured to suit the needs and requirements of different networks. Unlike unmanaged switches that function only to facilitate communication between two network nodes, managed switches can be customized to read data for accuracy and consistency before forwarding it to its destination.
  
  

Traffic Monitoring and Error Diagnosis

• Managed switches monitor traffic on a network and maintain extensive statistics for each network node or port. They ensure the smooth functioning of a network by analyzing its traffic capacity and disallowing access to nodes that lay stress on the network. Managed switches control and manage other port parameters, such as whether a port operates at full duplex or half duplex, whether or not a port is enabled, the quality of signal to a port and its speed. Managed switches also maintain statistics for individual ports, including the number of received and transmitted bytes, the number of errors generated in each port and whether the link on a port is down or up. These statistics are useful in isolating faulty or bad quality nodes, identifying top network talkers and even faulty network interface cards.
  
  

Secure

• Managed switches, unlike unmanaged switches and hubs, are secure as they direct data only to a specified Media Access Control (MAC) address on the network. Each device on a network has a unique MAC address, which can be thought of as its identification number. Managed switches receive destination MAC addresses embedded within a packet of data, which they then route to the required network node. This ensures security and prevents other nodes from accessing vulnerable and secure data. According to James L. Antonakos and Kenneth C. Mansfield in "Computer Networking for LANs to WANs: Hardware, Software and Security," network integrity is another advantage of specific packet forwarding, since managed switches are less vulnerable to security breaches and faults than unmanaged switches and hubs.