Menene DNS?
Duk lokacin da ka buɗe gidan yanar gizo, sabis ɗin adireshi marar ganuwa yana fassara sunan da ka buga zuwa lambar da kwamfutarka za ta iya kaiwa. Ga yadda Tsarin Sunan Domain ke aiki - da yadda ake karanta abin da yake bugawa game da kowane yanki.
Littafin waya na intanet
Kwamfutoci ba sa lilo da suna - suna haɗi zuwa Adireshin IP. DNS, da Tsarin Sunan yanki, shine kundin adireshi wanda ke tsara taswirar sunaye masu mantawa kamar example.com ga wadancan lambobin. An ƙirƙira shi a cikin 1983 daidai saboda farkon fayil ɗin mai watsa shiri na intanet a Stanford ya zama ba zai yiwu a kiyaye shi ba.
Abubuwa biyu suna sa DNS mai ban mamaki: shi ne rarraba (babu injin guda daya da ya san komai), kuma haka ne cache ko'ina (ana tunawa da amsoshi na ɗan lokaci, don haka dubawa yana da sauri). Duk kaddarorin biyu suna siffanta yadda tsarin ke aiki kowace rana.
Abin da ke faruwa yayin binciken DNS
Lokacin da mai binciken ku ya nemi gidan yanar gizon, jerin sabar DNS suna haɗin gwiwa a cikin 'yan milliseconds:
# 1. Na'urarka tana tambayar mai daidaitawarta (sau da yawa ISP's, ko 8.8.8.8 / 1.1.1.1) # 2. Mai warwarewa, idan ba a adana amsar ba, yana tafiya cikin matsayi: # tushen sabobin → ".com" sabobin → example.com na kansa sabobin # 3. Babban uwar garken yanki yana amsawa tare da ainihin bayanan # 4. Mai warwarewa ya adana amsar TTL ɗin rikodin kuma ya ba ku amsa
Hoton ƙarshe - uwar garken da ke magana don yankin kanta - shine abin da bayanan NS (a ƙasa) ke nunawa. Duk abin da ke sama wakilai ne kawai.
Nau'in rikodin da ke da mahimmanci
Yankin DNS na yanki ƙaramin rumbun adana bayanai ne na rubutattun bayanai. Waɗannan su ne ainihin waɗanda za ku ci karo da su:
| Nau'in | Abin da yake yi | Misali |
|---|---|---|
| A | Taswirar suna zuwa adireshin IPv4 | example.com → 93.184.216.34 |
| AAAA | Taswirar suna zuwa adireshin IPv6 | example.com → 2606:2800::2201 |
| CNAME | Alias: yana nuna suna a wani suna | www.example.com → example.com |
| MX | Sabar saƙon da ke karɓar imel ɗin yankin | 10 aspmx.l.google.com |
| TXT | Rubutun kyauta: SPF anti-spam, DKIM, hujjojin mallaka | "v=spf1 -all" |
| NS | Ikon sabar suna don yankin | ns1.examplehost.com |
| CAA | Wace hukumomin takardar shaida za su iya ba da takaddun shaida na TLS | 0 issue "letsencrypt.org" |
| SOA | metadata yanki: uwar garken farko, lamba, masu ƙidayar caching | ns1. dns-admin. … |
| PTR | Baya: taswirar IP zuwa sunan mai masauki | 8.8.8.8 → dns.google |
Abubuwa biyu sun cancanci sanin: CNAME shine ba a yarda ba akan tushen yankin (shi yasa example.com yana amfani da rikodin A/AAAA kai tsaye), da yanki tare da MX "0 ." yana da a nufa MX - hanyar da gangan ta faɗi "wannan yanki yana aika imel amma ba ya karɓar ko ɗaya".
Caching, TTL da yadawa
Kowane rikodin yana ɗauke da a TTL (lokacin rayuwa) - adadin masu warwarewa na iya sake amfani da amsar kafin sake tambaya. TTL na dakika 3600 na nufin har zuwa awa daya na caching a duk duniya; TTL na daƙiƙa 60 na nufin canje-canje suna bayyana a ƙasa da minti ɗaya.
Wannan shi ne abin da mutane ke nufi da "Yaduwan DNS": babu watsa shirye-shiryen canje-canje, kawai caches yana ƙarewa a kan nasu taki. Kafin ƙaura da aka shirya, dabarar gargajiya ita ce a rage TTL a gaba, yin canji, kallon sa a ko'ina cikin sauri, sannan sake tayar da TTL don jin daɗin caching.
Tukwici na magance matsala: idan rukunin yanar gizon ya yi lodi ga wasu amma ba don ku ba, mai warware matsalar ku na iya har yanzu riƙe tsohuwar amsar da aka adana. Canja na'urarka zuwa 1.1.1.1 ko ɓata cache na DNS yawanci yana daidaita shi.
Duba kowane yanki na DNS da kanka
Ba kwa buƙatar kayan aikin layin umarni - tambayar kayan aikin binciken mu na Google da masu warwarewar Cloudflare suna rayuwa:
- Mai duba DNS - ja kowane nau'in rikodin kowane yanki a cikin dannawa ɗaya.
- Domain zuwa IP - duba kawai adreshin da wani yanki ke nunawa, tare da cikakkun bayanai na baƙi.
- Duban IP na baya - rikodin PTR: wanda sunan mai masaukin IP ya amsa.
Ƙara koyo
- Kuna sha'awar lambobi a wancan gefen? Karanta menene adireshin IP ko kuma IPV4 vs IPV6 kwatanta.
- Binciken sunan IP? Duba cikin IP blacklists jagora.
Tambayoyin DNS
Menene DNS a cikin sauki kalmomi?
DNS (Tsarin Sunan Domain) shine littafin waya na intanet: yana fassara sunayen da zaku iya bugawa, kamar misalin.com, cikin adiresoshin IP da kwamfutoci da gaske suke haɗawa da su. Idan ba tare da shi ba, dole ne ku haddace adiresoshin lamba ga kowane gidan yanar gizon.
Menene adiresoshin 8.8.8.8 da 1.1.1.1?
Su ne masu warware DNS na jama'a waɗanda Google da Cloudflare ke gudanarwa. ISP ɗin ku yana gudanar da ɗaya ta tsohuwa, amma kowa zai iya tambayar waɗannan jama'a maimakon - suna da kyauta, sauri kuma sau da yawa mafi sauri don ɗaukar canje-canjen DNS. Kayan aikin mu na DNS suna tambayar su duka biyu akan rufaffen DNS-over-HTTPS.
Yaya tsawon lokacin canjin DNS ke ɗaukar aiki a ko'ina?
Muddin TTL ɗin da ta gabata (lokacin rayuwa). Amsoshin cache masu warwarewa na tsawon TTL - daƙiƙa zuwa kwanaki - don haka bayan kun gyara rikodin, masu warwarewa a duk duniya suna ci gaba da ba da tsohuwar amsar har sai kwafin su ya ƙare. Rage TTL kafin canje-canjen da aka tsara don sa sauyawa cikin sauri.
Menene bambanci tsakanin DNS da adireshin IP?
Adireshin IP shine lambar da ke gano na'ura akan intanet; DNS shine tsarin da ke yin taswirar sunayen yanki masu mantawa zuwa waɗannan lambobin. Yankin shine sunan, IP shine wurin da ake nufi, kuma DNS shine fassarar tsakanin su.