Local Area Network (LAN) - CCNA Study Material

Local Area Network (LAN) is a collection of connected devices in a small area. A home network (one router connected to computers and smartphones) is an example of a LAN.

Ethernet is the popular LAN technology today.

LAN helps to communicate between devices in a smaller area and improve the efficiency of working in an office.

Which Network Is a LAN?

So, how do we decide if a network is a LAN? In a LAN, all devices are connected and can share data. A LAN covers a small area (such as an office building, home, etc.).

The media type used to connect devices in a Local Area Network(LAN) is Ethernet, FDDI, Token Ring, etc.

Let us consider common topologies used in Local Area Networks because it is in the CCNA Exam Syllabus.

Topology is of two types: physical and logical topology.

In Physical Topology, you can see how devices in a LAN are connected, but in Logical Topology, we can see how these devices communicate.

LAN Physical Topologies

  1. Point to Point

    If we connect two devices without interference from other devices, that is a Point-To-Point physical topology. In this LAN topology, these two devices can communicate without extra support.

    Wireless Bridge is an example of Wireless Point-to-Point Topology.

  2. Bus Topology

    You can say it is an extension of Point-to-Point topology. In Bus topology, we connect all devices in LAN in a single connection.

    Ethernet uses Bus topology.

  3. Ring

    If a Local Area Network has Ring Topology, all devices are in a ring form. It means PC 1 connects to PC 2. PC 2 connects to PC 3, and the last device connects to PC 1. So, it forms a ring structure.

    FDDI uses a ring topology.

  4. Star Topology

    In start topology, all devices in a LAN have a connection to the central device. An example is all the computers connected to a Switch.

LAN Logical Topologies

  1. Bus Topology

    Ethernet is an example of a LAN technology using a logical bus structure to communicate. To learn more about Ethernet, visit the link below.

  2. Ring Topology

    Token Ring is a good example that uses ring logical topology to communicate computers connected to the network.

The medium of Transmission in LAN

  1. Twisted-pair wire

  2. Coaxial cables

  3. Fiber optic cables