Networking DevicesDCS201- Computer Science

By:Dilum Bandara

Outlinep LAN equipmentsn Network cardsn Repeatersn Hubn Bridgesn Switch

p WAN equipmentsn Routers

Network cardsp Are the devices attached to the computerp Provides the interface between the

computer & the networkp Belongs to the physical & data link layerp Ethernet usesn Thin & Thick Ethernet Coaxial with BNC

connectorsn 10/100/1000 Ethernet - UTP Cat5 with RJ45

connectors

Repeaters/Hubsp Works at the physical layerp These devices just retransmit the packets

that they receiven Amplifies the signal & increase the overall

distancen Restores the amplitude of the signal

p Ethernet can be extended using repeatersp Can be used for dissimilar mediap Different LANs cannot be converted

Hub

Collision domain

Bridges/Switchesp Operates at Data-link layer or MAC layerp Multiple LANs can be connectedp Can connect similar LANs with dissimilar

mediap Can link LANs of different speedsp Management software could be used to

manage the switches

Bridges/Switches contp Passes Packets to the other segment only

if addressed is part of that segmentn Builds an address data base dynamically (a

table with port address combinations) & use this to filter traffic

n Hence collision domains are extended only if required

Switches cont

Switches break collision domains

Broadcast domains

Routersp Are Network layer devicesp Can connect dissimilar LANs on the same

protocolp Some routers have support for may

protocols & protocol conversionp Can build large complex networks with

complex traffic routingp Limits the flow of broadcastsp Load sharing and balancing can be done

Gatewayp Connects multiple networksp Passes packets from one to anotherp When data packets needs to be send to

another network (beyond the current LAN) they are send to the default gateway

IP Addressing

DNS