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LAN Devices. 5.3 IT Essentials. LAN Devices— Host. Provides users with connection to network computers (both clients and servers) printers scanners other user devices Connects directly to a network segment Operates at all 7 layers of the OSI model. LAN Devices— NIC.
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LAN Devices 5.3 IT Essentials
LAN Devices—Host • Provides users with connection to network • computers (both clients and servers) • printers • scanners • other user devices • Connects directly to a network segment • Operates at all 7 layers of the OSI model
LAN Devices—NIC • Network interface card • Printed circuit board usually installed inside a computer case • Also called network adapter • Adapts host device to the network • Layer 2 device • Carries a unique code called a MAC address
LAN Devices—Media • Carries a flow of information, in the form of bits and bytes, through a LAN • Considered layer 1 component • Includes • Cat 5 UTP • optical fiber • free space • coaxial cable
LAN Devices—Repeater • Regenerates and retimes network signals • Allows signal to travel a longer distance on the media • Single-port “in” and single-port “out” device • Classified as layer 1 device
LAN Devices—Hub • Regenerates and retimes network signals • Also known as a multi-port repeater • Creates central connection point for wiring media • Classified as layer 1 device • Can be active or passive • Can be “intelligent” or “dumb”
LAN Devices—Bridge • Connects two LAN segments to make one larger continuous LAN • Filters LAN traffic to keep local traffic local • Allows connectivity to other parts of the LAN • Simple to install and manage—costs less than router • Checks MAC address to make forwarding decisions • Considered layer 2 device
LAN Devices—Switch • Sometimes called a multi-port bridge • Switches data from incoming port to outgoing port • Forwards data only to the appropriate port for the intended recipient • Concentrates connectivity to make data transmission more efficient • Considered layer 2 device
LAN Devices—Router • Most important traffic-regulating device on a network • Examines incoming packets • Chooses the best path for them through the network • Switches them to the proper outgoing port • Bases forwarding decisions on network addresses • Considered layer 3 device • Provides Internet access • Interconnects multiple LANs
Wireless LAN • Client with wireless NIC • NIC uses radio technology to transmit a signal through the air, instead of over a wire • Correctly deployed access point • Access point performs many of the same functions as simple hub • Access point sometimes acts as a bridge to a wired Ethernet network
LAN Devices—Cloud • Suggests another network, perhaps the entire Internet • Represents a large group of devices that connect any one computer to a distant computer • A collection of devices that operate at all levels of the OSI model so is classified as a Layer 1-7 device