Inqolobane ye-DNS (ngezinye izihlandlo ebizwa ngokuba yi-DNS resolver cache) yinkcukacha yesikhashana, egcinwe yinkqubo yokusebenza yecomputer, equlethe iirekhodi zazo zonke iindwendwe zandwendwe kunye nokuzama ukuvakashela kwiiwebhusayithi nakwezinye iindawo ze-intanethi.
Ngamanye amazwi, i-DNS cache nje imemori ye-DNS lookups yangoku kwikhompyutha yakho ingasetyenziswa ngokukhawuleza xa izama ukujonga indlela yokulayisha iwebsite.
Uninzi lwabantu luva kuphela ibinzana elithi "DNS cache" xa libhekisela ekutshiseni / kucima i-DNS cache ukuze kuncede ukulungisa ingxaki yokuxhumeka kwi-intanethi. Kukho ngaphezulu kwizantsi kweli phepha.
Injongo ye-DNS Cache
I-intanethi incike kwi- Domain Name System (DNS) ukugcina isalathiso kuzo zonke iiwebhsayithi zoluntu kunye nee- IP zamakheli ezihambelana nazo . Unokuyicinga njengencwadi yefowuni.
Ngefowuni yefowuni, akufanele senze ngekhanda inombolo yomnxeba wonk 'ubani, yindlela ephela kuphela yeefowuni ezinokunxibelelana: ngenani. Ngendlela efanayo, i-DNS isetyenziselwa ukuba sinokuphepheka ukuba siyikhumbule idilesi nganye ye-intanethi, yindlela ephela yendlela yokunxibelelana inxibelelwano kunye newebhusayithi.
Oku kwenzeka emva kwekhethini xa ucela isiphequluli sakho sewebhu ukuba ulayishe iwebhusayithi ...
Uthayipha kwi URL efana kwaye isiphequluli sakho sewebhu sicela i- router yakho kwidilesi ye-IP. I-router inedilesi yesiphakeli se- DNS igcinwe, ngoko icela iseva ye-DNS kwidilesi ye-IP yaloo gama lomninimzi . Umncedisi we-DNS ufumana idilesi ye-IP leyo kwaye uyakwazi ukuqonda ukuba yeyiphi iwebhusayithi oyicelayo, emva koko isiphequluli sakho sinokulayisha iphepha elifanelekileyo.
Oku kwenzeka kuzo zonke iiwebhusayithi ofuna ukuzityelela. Njalo xa umsebenzisi a tyelela iwebhusayithi ngegama lakhe lomncedisi, umshicileli wewebhu uqala isicelo kwi-intanethi, kodwa esi sicelo asikwazi ukuzaliswa de igama elithi "liguqulwe" kwidilesi ye-IP.
Ingxaki kukuba nangona kukho iitoni zeeseva zikaRhulumente ze-DNS inethiwekhi yakho ingasebenzisa ukuzama ukukhawulezisa inkqubo yokuguqulwa / isisombululo, kusasaza ukuba nekopi yendawo "yencwadi yefowuni," apho i-DNS caches ifika khona ukudlala.
Inqolobane ye-DNS izama ukukhawulezisa inkqubo ngakumbi nangokusingatha isigqibo segama lamakheli athanjelwe kutshanje ngaphambi kokuba isicelo sithunyelwe kwi-intanethi.
Qaphela: Kukho ngokwenene i-DNS caches kuwo onke ama-hierarchy of "lookup" kwinkqubo ekugqibeleni ifumana ikhompyutha yakho ukulayisha lewebhu. Ikhompyutheni ifinyelela kwi-router yakho, edibana no- ISP wakho, onokuyifumana enye i-ISP ngaphambi kokuba ugqibe kwizinto ezibizwa ngokuba yi "root server". Ngolunye lwezo ngongoma kule nkqubo ineCache ye-DNS ngesizathu esifanayo, okukukhawulezisa inkqubo yokulungisa isigama.
Indlela i-DNS Cache isebenza ngayo
Ngaphambi kokuba i-browser iqwalasele izicelo zayo kwinethiwekhi yangaphandle, ikhompyutheni iyalalelana nganye kwaye ibhekise kwigama lesizinda kwiDNS yedatha yedatha. Idatha iqulethe uludwe lwawo onke amagama angqamngca afumanekayo kunye needilesi ezazisiwe i-DNS okokuqala isicelo senziwe.
Okuqulathwe kwisilondolozi se-DNS sendawo singabonwa kwiWindows usebenzisa umyalelo ipconfig / displays, kunye neziphumo ezifana nale:
docs.google.com
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Igama leRekhodi. . . . . : docs.google.com
Uhlobo loRekhodi. . . . . : 1
Isikhathi Sokuphila. . . . : 21
Ubude beDatha. . . . . : 4
Icandelo . . . . . . . : Impendulo
A (Umphathi) Rekhoda. . . : 172.217.6.174
Kwi-DNS, i-"A" irekhodi isahlulo sokungena kwe-DNS equlethe idilesi ye-IP yegama elinikiweyo. Inqolobane ye-DNS igcina le dilesi, igama lewebhusayithi eliceliwe, kunye nezinye iipamitha ezivela kwi-DNS yokungenisa.
Yintoni i-DNS Cache Poisoning?
Inqolobane ye-DNS iya kuba yityhefu okanye ihlambuluke xa amagama e-domain engagunyazisiweyo okanye idilesi ze-IP efakwe kuyo.
Ngamanye amaxesha i-cache ingabonakaliswa ngenxa yezinto zobuchwephesha okanye izingozi zezolawulo, kodwa i-DNS cache ityhefu ixhomekeke kwiintsholongwane zekhomputha okanye ezinye iintambo zenethiwekhi ezifakela ukungena kwi-DNS engavumelekanga kwi-cache.
Utyhefu lubangela izicelo zabaxhasi ukuba zihanjiswe kwiindawo ezingalunganga, ngokuqhelekileyo iiwebhusayithi ezinobungozi okanye iphepha elipheleleyo lezipapasho.
Ngokomzekelo, ukuba irekhodi ye docs.google.com evela phezulu ingenalo "irekhodi" eyahlukileyo, ngoko xa ungena docs.google.com kwisiphequluli sakho sewebhu, uya kuthathwa kwenye indawo.
Oku kubangela ingxaki enkulu kwiiwebhusayithi ezidumile. Ukuba umhlaseli ulungisa isicelo sakho se-Gmail.com , umzekelo, kwiwebhusayithi ekhangeleka njengeGmail kodwa ayikho, unokuphelisa ukubandezeleka ekuhlaselweni kobuqhetseba obufana ne- whaling .
I-DNS Ukutshatyalaliswa: Yintoni Eyenzayo Nendlela Yokuyenza
Xa unenkinga yokucoca ubuthi okanye ezinye izinto zokuxhuma kwi-intanethi, umlawuli wekhompyutha unokufisa ukucoca (okwemhlophe, ukusetha kabusha okanye ukucima) i-DNS cache.
Ekubeni ukucima i-DNS cache kususa onke amafayile, kususa nayiphi na irekhodi engafanelekanga kwaye iqhube ikhomputha yakho ukuyibuyisela kwakhona loo dilesi ngexesha elizayo xa uzama ukufikelela kwezo website. Ezi dilesi ezintsha zithathwa kwi-DNS iseva yakho inethwekhi ukusetyenziselwa ukusebenzisa.
Ngoko, ukusebenzisa umzekelo ongasentla, ukuba irekhodi ye-Gmail.com ifakwe ngetyhefu kwaye ikuhanjiswe kwiwebhusayithi engaqhelekanga, ukukhupha i-DNS yinto yokuqala yokuqala yokufumana i-Gmail.com rhoqo.
KwiMicrosoft Windows, unokwazi ukucima i-DNS cache yangaphakathi usebenzisa umyalelo we- ipconfig / flushdns kwi- Prompt Command . Uyazi ukuba kusebenza xa ubona ukucwangciswa kwe-IP IP ngokukhawuleza kwacima i-DNS Resolver Cache okanye iphumelele ngokucoca umyalezo we-DNS Resolver Cache .
Ngokusebenzisa i-terminal command, abasebenzisi be-MacOS kufuneka basebenzise i- dscacheutil -flushcache , kodwa yazi ukuba akukho myalezo "uphumelele" emva kokuba uhamba, ngoko awuxelelwa ukuba kusebenze. Abasebenzisi beLinux kufuneka bafake umyalelo we-/etc/rc.d/init.d/nscd kabusha .
I-router ingaba ne-DNS cache ngokunjalo, oko kutheni ukuvuselela i-router kudla ngokuba yinyathelo lokujongana neengxaki. Ngenxa yezizathu ezifanayo unokuthi uhluthe i-DNS cache kwikhompyutheni yakho, ungaqalisa kwakhona umbane wakho ukucima i-DNS engenayo egcinwe kwimemori yayo yesikhashana.