Introduction
Theroutercanalsobecalledagatewaydevice.TherouteristhenetworklayerrelayandthethirdlayerrelaytaskcompletedinOSI/RM.Itstoresandpacketforwardsthedatapacketsbetweendifferentnetworks.Itismainlytoseparatethenetworksindifferentlogics.Thedataistransmittedfromonesubnettoanother,andcanbeprocessedbytherouter'sroutingfunction.Innetworkcommunication,therouterhasthefunctionofjudgingthenetworkaddressandselectingtheIPpath.Itcanconstructaflexiblelinksysteminmultiplenetworkenvironments,andlinkeachsubnetthroughdifferentdatapacketsandmediaaccessmethods.Inoperation,therouteronlyacceptstheinformationtransmittedbythesourcestationorotherrelatedrouters.Itisaninterconnecteddevicebasedonthenetworklayer.
Routersareusuallylocatedatthenetworklayer,soroutingtechnologyisalsoatechnologyrelatedtothenetworklayer.Comparedwiththeearlybridges,routershavemanychangesanddifferences.Generallyspeaking,thelimitationsofanetworkbridgearerelativelylarge.Itcanonlyconnectnetworkswiththesameorsimilardatalinklayers,andcannotconnectnetworkswithlargedifferencesbetweenthedatalinklayers.Buttherouterisdifferent.Itbreaksthislimitationandcanconnectanytwodifferentnetworks.However,thereisaprincipletobeobservedbetweenthesetwodifferentnetworks,whichistousethesamenetworklayerprotocol,sothattheycanbeconnectedbytherouter.Insimpleterms,routingtechnologyisatechnologythatforwardsandexchangesnumerousinformationonthenetwork.Specifically,ittransfersinformationfromasourceaddresstoadestinationaddressthroughtheInternet.Routingtechnologyhasalsomadegooddevelopmentandprogressinthepastfewyears,especiallytheemergenceofthefifth-generationrouter,whichsatisfiespeople'scomprehensiveapplicationofdata,voiceandimage,andisgraduallyselectedandwidelyusedbymosthomenetworks.Inaddition,inthepastfewyears,mycountry'sroutingtechnologyhasbecomemoreandmoremature,andatthesametime,ithascombinedwithcontemporaryintelligenttechnology,sothatpeoplecanexperiencefastandrapidresultsintheprocessofusingroutingtechnology,therebypromotingandpromotingThedevelopmentoftheInternetandnetworktechnology.
TherouteristhemainnodedeviceoftheInternet.Therouterdeterminestheforwardingofdatathroughrouting.Theforwardingstrategyiscalledrouting,whichistheoriginoftheroutername.Asahubforinterconnectingdifferentnetworks,theroutersystemconstitutesthemaincontextoftheInternetbasedonTCP/IP.ItcanalsobesaidthatroutersconstitutethebackboneoftheInternet.Itsprocessingspeedisoneofthemainbottlenecksofnetworkcommunication,anditsreliabilitydirectlyaffectsthequalityofnetworkinterconnection.Therefore,incampusnetworks,regionalnetworks,andeventheentireInternetresearchfield,routertechnologyhasalwaysbeenatthecore,anditsdevelopmentprocessanddirectionhavebecomeamicrocosmoftheentireInternetresearch.Atthetimewhenmycountry’snetworkinfrastructureandinformationconstructionisintheascendant,discusstherole,positionanddevelopmentdirectionofroutersininterconnectionnetworks,aswellasthedomesticnetworktechnologyresearchandnetworkconstruction,andclarifytheimportanceofroutersandnetworkinterconnectionsinthenetworkmarket.Allkindsofspeciousconceptsof"haveimportantmeanings.
Principle
ThedevicesinthenetworkcommunicatewitheachothermainlybytheirIPaddresses,androuterscanonlyforwarddataaccordingtospecificIPaddresses.TheIPaddressiscomposedoftwoparts:thenetworkaddressandthehostaddress.IntheInternet,thenetworkaddressandhostaddressaredeterminedbythesubnetmask.ThesubnetmaskandtheIPaddressareboth32bits,andthetwoareone-to-onecorrespondence.The"1"inthesubnetmaskcorrespondstothenetworkaddressintheIPaddress,andthe"0"correspondstothehostaddress.TheaddressandhostaddressconstituteacompleteIPaddress.Inthesamenetwork,thenetworkaddressoftheIPaddressmustbethesame.CommunicationbetweencomputerscanonlybecarriedoutbetweenIPaddresseswiththesamenetworkaddress.Ifyouwanttocommunicatewithcomputersonothernetworksegments,itmustbeforwardedthrougharouter.IPaddressesofdifferentnetworkaddressescannotcommunicatedirectly,eveniftheyareveryclose,theycannotcommunicate.Multipleportsoftheroutercanbeconnectedtomultiplenetworksegments,andthenetworkaddressoftheIPaddressofeachportmustbeconsistentwiththenetworkaddressoftheconnectednetworksegment.Differentportshavedifferentnetworkaddresses,andthecorrespondingnetworksegmentsarealsodifferent,sothatthehostsineachnetworksegmentcansenddatatotherouterthroughtheIPaddressoftheirownnetworksegment.
Transmissionmedia
Routersaredividedintolocalroutersandremoterouters.Thelocalrouterisusedtoconnectthenetworktransmissionmedia,suchasopticalfiber,coaxialcable,andtwistedpair;theremoterouterisusedToconnecttothelong-distancetransmissionmedium,andrequirecorrespondingequipment,suchasatelephonelinewithamodem,andwirelessthroughawirelessreceiverandtransmitter.
Struktura
Napájecí rozhraní (POWER): Rozhraní je připojeno k napájecímu zdroji.
Tlačítko Reset (RESET): Toto tlačítko může obnovit tovární nastavení routeru.
Modul (MODEM) nebo port pro připojení routeru (WAN): Toto rozhraní používá k připojení k domácímu širokopásmovému modemu (nebo k přepínači) síťový kabel.
Port pro připojení počítače a routeru (LAN1~4): Toto rozhraní používá k připojení počítače k externímu síťovému kabelu.
Bootprocess
Asarouter,thereisalsoapartthatfunctionssimilartotheBIOSinourPCsystem,calledMiniIOS.MiniIOScanenableustobootupandentertherecoverymodewhenthereisnoISOintheFLASHoftherouter,touseTFTPorX-MODEMtoimportISOfilesintotheFLASH.Therefore,thestartupprocessoftheroutershouldbelikethis:
Po zapnutí routeru nejprve provede POST,PowerOnSelfTest (PowerOnSelfTest,processoftwarutestování)).
Po dokončení POST nejprve spusťte program BootStrap v ROM pro předběžnou pomoc.
Po úvodním spuštění zkuste vyhledat a přečíst úplný soubor obrazu ISO. Zde se nejprve podíváte na soubor ISO ve FLASH.
Pokud soubor ISO nenaleznete ve FLASH, router přejde do režimu BOOT a soubor ISO na TFTP lze použít v režimu BOOT. Nebo použijte TFTP/X-MODEM k přenosu souboru ISO z jiné vnější mise FLASH (obecně tento proces nazýváme, abyste mohli spustit převádění ISO, a poté znovu spustit). dennormálně.
Když router inicializuje soubor ISO, začne hledat soubor STARTUP-CONFIGv NVRAM.STARTUP-CONFIG se nazývá konfigurační soubor při spuštění. Tento soubor uloží všechny konfigurace a úpravy, které jsme provedli na jiném vnějším. přejděte do konfigurace a načtěte všechny konfigurace do paměti RAM (paměti routeru), poté přejděte do uživatelského režimu a nakonec dokončete proces spouštění.
Pokud v NVRAM není soubor STARTUP-CONFIG, přejde router do konfiguračního režimu dotazu, který je běžně známý jako konfigurační režim dotazů a odpovědí. V tomto režimu lze všechny konfigurace routeru nakonfigurovat ve formě dotazu a odpovědi. mandlinemodetoconfigureetherouter.
Funkční funkce
Hlavní funkciouter lze chápat jako realizaci přenosu informací.Proto tento proces nazýváme procesem orovnávání hlavy.Protože se mezi různými sítěmi není nutné, aby konečná adresa pro příjem informací byla v tabulce. informace zasílané přenosovou webovou stránkou, najděte další adresu pro přeposílání, která síť by měla být. Ve skutečnosti je to jako kurýrní společnost, která posílá poštu. Pošta nedorazí do konečného cíle okamžitě, ale je tříděna podle různých rozvoden a neustále se přibližuje ,čímž se realizuje proces doručovánípošty.Procesadresovánísměrovačůjepodobnýprincipu.Konečnáadresasepřiřadívtabulcesměrováníadalšíadresapropředáníjeurčenaalgoritmem.Tatoadresamůžebýtmeziadresou,nebomůžebýt konečnouadresou.
Thefunctionoftherouteristotransferdatabetweendifferentsubnets.Thespecificfunctionsareasfollows:
(1)Uvědomte si propojení IP, TCP, UDP, ICMP a dalších sítí.
(2)Zpracovávejte data. Odesílání a přijímání datových paketů má různé funkce, jako je filtrování datových paketů, multiplexování, šifrování, komprese a ochranné stěny.
(3)Selectthenexttransmissiondestinationofthedatapacketbasedontheinformationintheroutingtable.
(4)Performtheexchangeoftopologyinformationbetweentheexternalgatewayprotocolandotherautonomousdomains.
(5)Uskutečnění funkcí správy sítě a podpory systému.
Connectingdifferentnetworks
Fromtheperspectiveoffilteringnetworktraffic,theroleofroutersisverysimilartothatofswitchesandbridges.However,unlikeswitchesthatworkatthenetworkdatalinklayerandphysicallydividenetworksegments,routersusespecialsoftwareprotocolstologicallydividetheentirenetwork.Forexample,arouterthatsupportstheIPprotocolcandividethenetworkintomultiplesubnetsegments,andonlynetworktrafficdirectedtoaspecialIPaddresscanpassthroughtherouter.Foreachreceiveddatapacket,therouterwillrecalculateitscheckvalueandwriteanewphysicaladdress.Therefore,thespeedofusingaroutertoforwardandfilterdataisoftenslowerthanthatofaswitchthatonlylooksatthephysicaladdressofthedatapacket.However,forthosecomplexnetworks,theuseofrouterscanimprovetheoverallefficiencyofthenetwork.Anotherobviousadvantageofroutersisthattheycanautomaticallyfilternetworkbroadcasts.Generallyspeaking,theentireinstallationprocessofaddingaroutertothenetworkismuchmorecomplicatedthanaplug-and-playswitch.
Informationtransmission
Someroutersonlysupportasingleprotocol,butmostrouterscansupportthetransmissionofmultipleprotocols,thatis,multi-protocolrouters.Sinceeachprotocolhasitsownrules,itisboundtoreducetheperformanceoftheroutertocompletethealgorithmsofmultipleprotocolsinarouter.Themainjoboftherouteristofindanoptimaltransmissionpathforeachdataframepassingthroughtherouter,andtoeffectivelytransmitthedatatothedestinationsite.Itcanbeseenthatthestrategyofselectingthebestpath,thatis,theroutingalgorithm,isthekeytotherouter.Inordertocompletethiswork,varioustransmissionpathrelateddata—RoutingTable—isstoredintherouterforuseinroutingselection.Thepathtablestoresthesubnetidentificationinformation,thenumberofroutersontheInternet,andthenameofthenextrouter.Thepathtablecanbefixedlysetbythesystemadministrator.
Statické směrování
Thepathselectionusedispre-calculatedofflineanddownloadedtotherouterwhenthenetworkisstarted.Itcannotrespondtofailures,andstaticroutingisveryusefulforoccasionswhereroutingisalreadyclear.
Dynamicrouting
willchangetheirroutingdecisionstoreflectchangesinthetopology,andusuallyalsoreflectchangesintraffic.Dynamicroutingalgorithmsaredifferentinmanyaspects:thesourceofinformationisdifferent,thetimetochangethepathisdifferent,andthemetricusedforroutingoptimizationisdifferent.
Klasifikace
(1)Funkčně jej lze rozdělit na:směrovače na páteřní úrovni,podnikové úrovniapřístupovéúrovni.Propustnost dat z páteřních routerů je velká a důležitá a je klíčem k realizaci propojení sítí na podnikové úrovni.Rychlost páteřních routerů vyžaduje vysokou rychlost práce. ,duální napájecí zdroje a duální datové cesty pro zajištění jejich spolehlivosti. Směrovače na podnikové úrovni jsou připojeny k mnoha terminálovým systémům, které jsou jednoduché a mají malý datový provoz.
(2)Strukturu lze rozdělit na: modulární a nemodulární směrovače. Modulární směrovače mohou realizovat flexibilní konfiguraci směrovačů a přizpůsobit se obchodním potřebám podniků; nemodulární směrovače mohou poskytovat pouze jeden pevný port.
(3)Dividedinto"borderrouter"and"intermediatenoderouter"accordingtothenetworklocation.Routersinthewideareanetworkcanbedividedintotwotypesaccordingtotheirmessageforwardingperformance,namely,borderroutersandintermediatenoderouters.
Hraniční třída
Althoughinvariousroutingprotocolsthatareconstantlyimproving,thenamesusedforthesetwotypesofroutersmaybequitedifferent.Buttheroleplayedisthesame.Obviously,the"borderrouter"isattheedgeofthenetworkandisusedtoconnectdifferentnetworkrouters;whilethe"intermediatenoderouter"isinthemiddleofthenetwork,andisusuallyusedtoconnectdifferentnetworks,actingasadataforwardingbridge.
Intermediatenodeclass
Whentheintermediatenoderouteristransmittinginthenetwork,itprovidesstorageandforwardingofmessages.Atthesametime,accordingtotheroutinginformationmaintainedbythecurrentroutingtable,thebestpathisselectedtotransmitthemessage.TherouterconnectedtotheexternalwideareanetworkonthesideofacompanyorenterprisenetworkcomposedofmultipleinterconnectedLANsistheconnectingrouterofthisenterprisenetwork.ItcollectstheinformationaddressedtothecorporatenetworkfromtheexternalWANandforwardsittotherelevantnetworksegmentsinthecorporatenetwork;ontheotherhand,itconcentratesthemessagessentfromeachLANsegmentinthecorporatenetworktotheexternalWAN,anddeterminesthebestrelatedmessages.Transmissionpath.
Themaintechnologyoftherouter
Backplanestructure
Thecoreoftherouteristhebackplane,andthehigh-efficiencybackplanehelpstoimprovetheperformanceoftherouter.Becausethetraditionalsharedbustypebackplanecannotmeettheneedsofrouters,itadoptsaswitchbackplanewhosestructurecanbeimplementedwithdifferenttechnologies.Banyanstructure,Crossbarstructureandparallelsharedstoragestructurearecommonlyusedstructuresforswitchedbackplanes.Banyanstructureusesself-routingtechnologyandmulti-levelbufferstructure;Crossbastructureisasingle-level,single-channel,non-blockingstructure,usingafullInternetswitchingstructure;parallelsharedstoragestructureisaresearchhotspot.
MobileIPtechnology
LETFestablishedaworkinggrouptosolvethesolutionthatpeoplewanttobeabletoconnectcomputersandlaptopstotheInternetatanyplace.TheworkinggroupsortedouttherealizationofanyTheconditionstobemetbyaplanareasfollows:
(1)Každý hostitel musí zajistit, aby jeho IP adresa mohla být použita na libovolném místě;
(2)FixedThehostcomputercannotchangethesoftwareequipment;theroutersoftwareandroutingtablecannotbechangedarbitrarily;
IPv6technology
TheexistingInternetoperatesonthebasisoftheIPv4protocol.WiththerapiddevelopmentoftheInternet,theemergenceoftheWebhasledtotheexplosivedevelopmentoftheInternet.ThelimitedaddressspacedefinedbyIPv4isinsufficient,andIPaddressesareunprecedentedlytense,affectingthefurtherdevelopmentoftheInternet,sothenextversionoftheInternetprotocol-IPv6isproposed.IPv6adoptsa128-bitaddresslengthandprovidesalmostunlimitedaddresses.ItnotonlysolvestheproblemsthatIPv4cannotsolve,butalsoaddsauthenticationandencryptionsecuritymeasuresattheIPlayertoensuresecurity.IPv6hastheadvantagesofexpandingtheaddressspace,increasingtheoverallthroughputofthenetwork,effectivelyimprovingthequalityofservice,ensuringsecurity,mobility,supportingplug-and-play,andrealizingmulticastfunctions.
Technologie VPN
VPN (virtuální soukromá síť) je nejdůležitějším druhem technologie pro routery.VPN odkazuje na soukromou síť, kterou lze spravovat v budově.Naše mohou uživatelé VPN ovládat spojení mezi sebou a ostatními uživateli a na všech PN mohou podporovat různé přístupy. spolehlivost, kvalita služeb, škálovatelnost, flexibilita a ovladatelnost.
VPRNtechnology
VPRNisavirtualprivateroutingnetworkindailynetworks.VPRNcandirectlycommunicatewitheachotherasiftheyareinthesamenetworksegmentbetweendeviceslocatedindifferentphysicalLANsegments.Theservicesincludedare:VPNusingtraditionalVPNprotocolsandMPLSmethods.SolutionstorouterVPNtechnologyinclude:settingaccesscontrol;encryptingcommunicationdata;NAT(NetworkAddressTranslationProtocol)technology.
Technologie Qo
QoSjekvalitaslužeb.Dříve se QoS používal výhradně v ATM.Jakobalenýprotokol však IP nemůže vyhovět rostoucí aplikaci multimediálních informací,což způsobuje problémy,jako jsou dlouhé zpoždění a nepoužité stálé hodnoty při ukládání a ukládání.
Themanufacturerprovidesanumberofsolutions:①Priorityofsomeequipmentdatapacketscanbesentlast-come-first;②Iftheuser'sprotocolhasahigherpriority,bothIntelandCiscosupportthelatterArrivalfirsttransmission;③ForlinkintegrationMLPPP,Ciscosupportstheuseofmultiplelinesconnectingtwopointstoincreasethebandwidth;④ForresourcereservationPSVP,partofthebroadbandisallocatedtothemultimediasignalinafixedformNomatterhowcrowdedotherprotocolsare,thispartofthebroadbandwillnotbeoccupied.
Developmenttrend
Traditionalroutershavetoperformaseriesofcomplexoperationswhenforwardingeachpacket,includingroutelookup,accesscontrollistmatching,addressresolution,prioritymanagementandotherAdditionaloperations.Theseoperationsgreatlyaffecttheperformanceandefficiencyoftherouter,reducethepacketforwardingrateandforwardingthroughput,andincreasetheburdenontheCPU.Thecorrelationbetweenthepacketsbeforeandaftertherouterisverylarge,andthepacketswiththesamedestinationaddressandsourceaddressoftenarriveinsuccession,whichprovidesthepossibilityandbasisforfastforwardingofpackets.Thenewgenerationofrouters,suchasIPSwitch,TagSwitch,etc.,usethisdesignideatoimplementfastforwardingwithhardware,therebygreatlyimprovingtheperformanceandefficiencyoftherouter.
Thenewgenerationofroutersusesforwardingbufferstosimplifypacketforwardingoperations.Inthefastforwardingprocess,onlythefirstfewpacketsofagroupofpacketswiththesamedestinationaddressandsourceaddressneedtobetraditionallyroutedandforwarded,andthedestinationaddress,sourceaddressandnextgatewayaddressofthesuccessfullyforwardedpacket(Thenextrouteraddress)isplacedintheforwardingbuffer.Whensubsequentpacketsaretobeforwarded,theforwardingcacheshouldbecheckedfirst.Ifthedestinationaddressandsourceaddressofthepacketmatchthoseintheforwardingcache,itwillbeforwardeddirectlyaccordingtothenextgatewayaddressintheforwardingcachewithoutgoingthroughthetraditionalThecomplexoperationoftheroutergreatlyreducestheburdenontherouter,therebyachievingthegoalofimprovingrouterthroughput.
Securityhazards
Practiceshowsthatduringtheapplicationofwirelessnetworkopticalfibercommunicationrouters,thereareoftencertainsecurityhazards,whichaffecttheapplicationofwirelessnetworkopticalfibercommunicationrouters.Qualityandcommunicationsecurity.Specifically,themainmanifestationsareasfollows.
Theconcealmentofwirelessnetworkroutingisnothigh
Animportantsecurityhazardduringtheuseofwirelessnetworkopticalfibercommunicationroutersistheproblemoflowconcealmentofwirelessnetworks.Becausewirelessnetworksmainlyuseradiofrequencytechnologytoimplementnetworkconnectionandtransmission,anduseradiowavestospreaddatawithinacertainrange,oncethedevicecoverageexceedstherangeoftheenterprise,hackerscaneasilylogintoWirelessnetwork,therebylaunchinganattackonthenetwork,whichleadstoapoorenvironmentfortheuseofwirelessnetworkopticalfibercommunicationrouters,andthesecurityindexcontinuestodecline,whichultimatelyaffectstheutilizationrateofusers.
Thereisaproblemofeavesdroppingonnetworkcommunication
Eavesdroppingonnetworkcommunicationmainlyrefersto:duringtheuser'suseofthenetwork,theattackermonitorstheuser'scommunicationinformationtoacertainextent,andpassesthecommunicationcontentthroughtheemulationterminalTheformofthemachinerevealsit.Althoughthenetworkisnotbroadcasttotheoutsideworld,somenetworkattackerscanstillmonitoritthroughsomenetworktoolsandsoftware,andanalyzethetraffic,finally.Identifyinformationthatcanbedestroyed.Oncetheintrudersuccessfullylogsontothewirelessnetwork,itwillposeaseriousthreattothecorporatenetworkandtradesecrets.
Denialofserviceattack
Oneofthemostcommonlyusedsupplymethodsbyhackersisadenialofserviceattack.Inotherwords,thetargethostcannotcontinuetoprovideservices.Frequency,thiswillcausecertainconflictsinthewirelessspectrum,whichwillsendsomeillegalauthenticationrequests,etc.,andthetrafficcannotbetransmittedtothedestination,whichwilleventuallycauseuserstobeunabletousethenetworknormally,whichbringsgreatimpacttotheuser’swork.Troubled.
Safetyprotectionmeasures
Routersareatransitionaltoolforthenetwork,anditalsoplaysaveryimportantroleintheuseofthenetwork.Routervulnerabilitiesaremainlydividedintopasswordcrackingvulnerabilities,Webvulnerabilities,backdoorvulnerabilitiesandoverflowvulnerabilities,butmostoftheroutervulnerabilitiesarerelatedtothequalityoftherouter.Eachrouterhasatleasttwoportsconnectedtotwonetworks.Agoodqualityrouterwillusestrictsecuritymechanismstoprotectitself,andatthesametime,itwillalsoprotecttheconnectedcomputernetworktopreventthepasswordfrombeingcracked.Orleaveabackdoorthatistooobvious.Inaddition,theinstallationofnetworkmanagersandroutersshouldalsoprovidecertainsecurityprotectiontotheequipmenttoisolatethedangerfromtherootcause.ForBGPvulnerabilities,themosteffectivesolutionistosolvetheproblemattheISPlevel.Atthenetworklevel,itistomonitortheroutingofinbounddatapacketsandsearchforanyabnormalitiestosolvethem.Atthesametime,asusersofroutersandnetworkequipment,theyshouldlearnandunderstandthesecurityperformanceofrouters,payattentiontothepasswordsettingsofrouters,etc.,toavoidleavingopportunitiesforcriminals,andatthesametimeWhenthereisaproblemwiththeequipment,itisnecessarytofindrelevantpersonneltodealwithandsolveitintimetominimizethedamageandloss.
Wirelessrouter
WirelessrouterisarouterwithwirelesscoveragefunctionthatisusedforuserstosurftheInternet.Itcanberegardedasarepeatertoforwardbroadbandnetworksignalsthroughantennas.Tonearbywirelessnetworkequipment.Thepopularwirelessroutersonthemarketgenerallysupportfouraccessmethodsofdedicatedlinexdsl/cable,dynamicxdsl,andpptp.Italsohasothernetworkmanagementfunctions,suchasdhcpservice,natfirewall,macaddressfiltering,dynamicdomainnameandotherfunctions.CommonwirelessroutersgenerallyhaveaRJ45portastheWANport,whichistheinterfacefromUPLinktotheexternalnetwork,andtheremaining2-4portsareLANports,usedtoconnecttoacommonlocalareanetwork.Thereisanetworkswitchchipinside,whichspecializesinprocessingtheLANinterface.Exchangeofinformationbetween.Generally,theworkingmodeoftheroutingbetweentheWANportofthewirelessrouterandtheLANgenerallyadoptstheNATmode.Therefore,infact,thewirelessroutercanalsobeusedasawiredrouter.