AddressProtocol
TheInternetreliesontheTCP/IPprotocoltorealizetheinterconnectionofdifferenthardwarestructures,differentoperatingsystems,anddifferentnetworksystemsonaglobalscale.OntheInternet,eachnodereliesonauniqueIPaddresstodistinguishandcommunicatewitheachother.TheIPaddressisa32-bitbinarynumberaddress,composedof48-bitfields,eachfieldisseparatedbyadot,usedtoidentifytheTCP/IPhost.
EachIPaddresscontainstwoparts:networkIDandhostID.ThenetworkIDidentifiesallhostsonthesamephysicalnetwork,andthehostIDidentifieseachhostonthephysicalnetwork,soeverycomputerontheentireInternetisidentifiedbyitsownuniqueIPaddress.
TheIPaddressconstitutesthebasisoftheentireInternet.ItissoimportantthateverynetworkedcomputerhasnorighttosetitsownIPaddress.Thereisaunifiedorganization-IANAisresponsibleforassigninguniquenesstotheorganizationapplyingforit.TheorganizationcanassignauniquehostIDtoeachhostinitsownnetwork,justasanorganizationhasnorighttodetermineitsownstreetnameandhousenumberinthecitytowhichitbelongs,butcanindependentlydeterminethevariousinternalTheofficenumberisthesame.
Classification
Networkaddressesarecurrentlydividedintofivecategories,representedbytheEnglishlettersA,B,C,D,andE.Theyaredividedintotwoformatsegments,withthenetworknumberinfront.Thehostnumberfollows.StartingfromTypeA,thelengthofthepreviousnetworknumberiseight,sixteen,andtwenty-fourdigits.Ifyousimplyunderstand,becausethenetworknumberoftypeAhasonlyeightdigits,therearefewernetworknumbersthatcanbeallocated,andtypeDandEarededicatedcategories,sothemostusedaretypesBandC.Theyaredistinguishedbythefixedsequencenumberatthefront.
Addresstype
IPv4
ThecharacteristicsofIPv4aremainlyreflectedinthefollowingaspects:
(1)IPv4addressspaceislessthan4billion,feweractuallycanbeused.
(2)IPv4doesnotdistinguishbetweennetworkterminalhostsandterminaldevices,andeachcomputercanbeusedasahostandarouter.Theroutingprotocolmanagesroutingtablerecords.Commonroutingprotocolsincluderoutinginformationprotocol,openshortestpathprotocol,bordergatewayprotocol,etc.
(3)IPv4isindependentofspecificnetworkhardwareandcanrunonlocalareanetworks,wideareanetworks,andtheInternet.Thenetworkaddressallocationplanisunique,andthedevicehasauniqueaddress.
(4)IPv4lackssecuritysupportandcannotrealizethenetworkreal-namesystem.Thenodeconfigurationinthenetworkisverycomplicatedandcannotmeettheuser's"plugandplay"demand.
IPv6
ThemainfeaturesofIPv6areasfollows:
(1)IPv6addresslengthis128bits,whichisconvenientforhierarchicalmanagementstructureandimprovesthroughputAndnetworktransmissionefficiency.
(2)IPv6hashighersecurityandprovidesprivacysettingssuchasidentityauthenticationandprivacy.
(3)IPv6addsmulticastsupportandconvectionsupporttoensurethequalityofservice.Inaddition,IPv6canalsouseautomaticconfiguration,whichisconducivetonetworkmanagementandconvenientapplications.
Thereareproblems
ThesolutiontotheshortageandwasteofnetworkaddressesproducessubnetstoreducethewasteofIP.Inrecentyears,withthecontinuousemergenceofnewnetworksandtherapiddevelopmentofnetworktechnology,underthecurrentIPV4protocol,someofthenewnetworkterminalsproducedhavehundredsof,andsomehaveonlyafew,whichresultsinIPaddresses.Inordertoreducetheoccurrenceofthiskindofwaste,subnetdivisioncameintobeing.Theimportantfeatureofsubnettingisthesubnetmask.ThesubnetmaskcandividetheIPaddressintotwoparts:thehostaddressandthenetworkaddress.SubnettingcanpartiallyshieldtheIPaddress,andthendistinguishthehostIDandthenetworkID,indicatingthatitisanIPonaremotenetworkoranIPonalocalareanetwork,andsubnettingcandividealargenetworkintoasmallnetworkthatiseasytomanage.AnothermethodisNATaddresstranslation:NetworkaddresstranslationisalsoNATtechnology.TheIPV4protocolcommonlyusedintheInternetnowhasmanydefects,butthetimeperiodforthedevelopmentandwidespreaduseofIPV6islong,andNATtechnologycaneffectivelyextendtheservicelifeofIPV4.NATcanmodifytheIPinthesourcedatapackettoshieldtheinternalnetwork.IfyouwanttoincreasethescopeofuseofNAT,newperformancedevelopmentmustbecarriedout.ThekeystepofNATtechnologyistheformationofthetranslationtableontheNATconfigurationrouter.AslongastheformationoftheNATtranslationtableiscompleted,allworkisbasicallyfinished.
Developmenttrend
ThenetworkaddresscomplieswiththeIPV4protocol.Withthecontinuousincreaseofnetworkusers,therehasbeenatrendthatcannotmeettheneedsofusers.ThenewdevelopmentdirectionisIPV6.Infact,itsdevelopmentiseasytounderstand.Since32bitscannolongermeetthedemand,themostdirectwayisofcoursetoextendthenumberofbits.IPV6expandstheaddressto128bits.However,sincethepreviousnetworkcommunicationhasalwaysusedthepreviousprotocol,theworkingstandardsofmanyhardwarecommunicationdeviceshavenotchanged,sothisisabottleneckprobleminthedevelopment.Tochangethestandardfromanewdevice,howtoconverttheworkingdesignstandardisanimportantissuetobeconsideredinpracticalapplications.
IPaddress
Definition
IPaddressisawayofaddressinghostsontheInternet.Eachcomputerisassignedalogicaladdress,sothatnotonlyThecomputercanidentifyandshareinformation.TheIPaddressisa32-bitbinarynumber,whichisusuallydividedinto4"8-bitbinarynumbers".TheIPaddressislikeahomeaddress.Ifauserwantstotransmitinformation,hemustknowtheIPaddress.Thehomeaddressismainlyexpressedinwords.TheIPaddressisrepresentedbybinarynumbers.OnlywhenusershaveacertaindegreeofunderstandingofIPaddressescantheyrealizetheroleofIPaddressesintheirlives,andtheneffectivelydivideIPaddresses.
Function
ThenetworkaddressisnotwritteninChinesecharacters,butisactuallya32-bitbinarynumberstream.Butallnetworkusershaveneverenteredabinarystreaminthenetwork,isthereanerror?Ofcoursenot,becausethe32-bitlengthistoolongandnoteasytoremember.Therefore,itisobviouslyinappropriatefornetworkuserstomemorizethe32-digitseries.Peoplecameupwithanotherrepresentationmethodcalleddotteddecimalnotation.Thespaceislimited.Simplyput,itistouse8-digitdecimalnumberstorepresentthe32-digitbinarynumberseries..Here,somefriendswhohavemorecomputeroperationsmayhaveacertainimpression.However,mostInternetusersstillenteraspecificURLinthebrowser,suchaswww.baidu.com,andweonlyneedtorememberthisname.Thisisthedomainnameresolutionofthenetworkaddressfortheconvenienceofusers.Inotherwords,itistogiveanetworkaddressamemorablename.Thereisaone-to-onecorrespondencebetweenthetwo.Usingthepreviousexample,"HarbinRailwayTechnicalVocationalCollege"correspondstoanaddress,whichinturnisrepresentedbythisname.Ifyouwanttogotothisaddressanddon'tknowwhereyouare,youtakeataxiandsaythename,andthedriverwillfindthecorrespondingplacebasedonthenameoftheunit.Sothetwocorrespondtoeachother.Allinall,thenetworkIPaddresscandescribethelocationofdifferentnodesinthenetwork,usesomeprotocolstoachieveaccess,andatthesametimeusesimpleandeasy-to-remembernamestoachieveaccess.