Definition

local area network (LAN)

Contributor(s): Diana Hwang

A local area network (LAN) is a group of computers and peripheral devices that share a common communications line or wireless link to a server within a distinct geographic area. A local area network may serve as few as two or three users in a home-office or several hundred users in a corporation’s central office. Home owners and information technology (IT) administrators set up LANs so that network nodes can share resources such as printers or network storage.

LAN networking requires cables, switches, routers and other components that let users connect to internal servers, websites and other LANs that belong to the same wide area network (WAN). Ethernet and Wi-Fi are the two primary ways to enable LAN connections. Ethernet is a specification that enables computers to communicate with each other. Wi-Fi uses radio waves to connect computers to the LAN.

Other LAN technologies, including Token Ring, fiber distributed data interface (FIDDI and ARCNET lost favor as Ethernet and Wi-Fi speeds increased and connectivity costs decreased.

Understanding local area networking

In many situations, a wireless LAN, may be preferable to a wired LAN connection because of its flexibility and cost. Companies assessing WLANs as primary means of connectivity often have users who rely exclusively on smartphones, tablets and other mobile devices to do work.

The rise of virtualization has also fueled the development of virtual LANs, which allows network administrators to logically group network nodes and partition their networks without the need for major infrastructure changes.

Setting up a basic local area network

Operating systems such as Microsoft Windows and Apple OS X have networking capabilities incorporated into them. This means that as long as the network administrator has a relatively up-to-date laptop or desktop PC, it is fairly straightforward to network machines together.

To set up a wireless network, the administrator will need a wireless router linked to a broadband connection and an Ethernet cable that links the router to the main PC or server.

This will then allow other computing devices which already have wireless networking equipment integrated or attached to them, to pick up wireless signals and join the local area network.

LAN security

Once the network has been set up, it must be secured. This can be done through security settings in the router, the use of strong passwords and frequent software updates. Hardware-based security such as fingerprint recognition, security tokens and full disk encryption can also be used to enhance network security. Additional security packages for protecting and maintaining the network perimeter can be installed locally or purchased through a Software-as-a-Service (SaaS) delivery model.

LAN topologies

Network topologies outline how devices in a LAN are connected, as well as how data is transmitted from one node to another. Popular topologies include:

This was last updated in July 2019

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