Routine and Switching Principles and Fundamentals

Network routing refers to the ability of an electronic communication network to send a unit of information from point A to point B by determining a path through the network by doing efficiently and quickly.
Routing Means finding all possible paths to destination networks and selecting the best path. Basic router functionality is comprised of three major components:
• Routing process • Routing protocols • Routing table

1. ROUTINE AND SWITCHING
PRINCIPLES
BY Ms. Javairia Nazir From IUB

2. ROUTING FUNDAMENTALS
Networkroutingreferstotheabilityofanelectroniccommunicationnetworktosendaunitof
informationfrompointAtopointBbydeterminingapaththroughthenetworkbydoingefficiently
andquickly.
RoutingMeansfindingallpossiblepathstodestinationnetworksandselectingthebestpath.Basic
routerfunctionalityiscomprisedofthreemajorcomponents:
•Routingprocess •Routingprotocols •Routingtable

3. ROUTING COMPONENTS
TheroutingprocessistheactualmovementofIPpacketsfromoneportto
anotherandtheroutingtableholdstheinformationusedbytheroutingprocess.
RoutingprotocolssuchastheRoutingInformationProtocol(RIP)orOpen
ShortestPathFirst(OSPF)areusedtocommunicatewithotherroutersandmay
endup“installing”routesintheroutingtableforusebytheroutingprocess.
Whenarouterisconfigured,theroutingtableisconstructedbybringing
interfacesupandprovidingtheinterfaceswithIPaddresses.

4. ROUTING PROCESS
Processthroughwhichdatapacketsaredirectedfromtheirsourcetotheirdestination
occursattheNetworkLayer(Layer 3)foehtISO forensuringcommunicationbetween
devicesindifferentnetworks
routerreceivesapacket,itexaminesthedestinationIPaddressinthepacketheader
andcomparesittoentriesinitsroutingtabletodeterminethebestpath
Therouterconsidersfactorssuchasmetrics(e.g.,hopcount,bandwidth,delay)and
administrativedistancetoselectthemostoptimalroute.
Oncethepathisdetermined,therouterforwardsthepacket
Effectiveroutingensuresminimaldelays,reducedpacketloss,andefficientuseof
networkresources.

5. ROUTING PROTOCOL
rulesandalgorithmsthatroutersusetodiscover,communicate,andshareinformation
aboutnetworks
enablerouterstobuildandmaintainroutingtables
Broadlycategorizedintothreetypes:
DistanceVectorProtocols:,ProtocollikeRIP(RoutingInformationProtocol),use
metricslikehopcounttodeterminethebestpath.However,mayconvergeslowlyand
lesssuitedforlargenetworks.
Link-StateProtocolsProtocolslikeOSPF(OpenShortestPathFirst)useacomplete
mapofthenetworktodeterminetheshortestpath.morescalableandofferfaster
convergence
HybridProtocols:protocolslikeEIGRP(EnhancedInteriorGatewayRoutingProtocol)
useadvancedmetricsandareefficientindiversenetworkenvironments.

6. ROUTING TABLE
A critical component of a router, functioning as a database that stores route
information for packet forwarding
contains a list of known networks, the paths to reach them, and associated metrics .
table typically includes:
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Administrative Distance (AD): A value that ranks the trustworthiness of a route
learned via different routing protocols.