{"id":138,"title":"DNS (Domain Name System) \u00c7al\u0131\u015fma Prensipleri","content":"DNS (Domain Name System), internet \u00fczerindeki alan adlar\u0131n\u0131 (www.ondernet.net gibi) IP adreslerine (142.250.190.14 gibi) \u00e7eviren sistemdir. Bu \u00e7eviri i\u015flemi, kullan\u0131c\u0131lar\u0131n ak\u0131lda kal\u0131c\u0131 alan adlar\u0131 kullanarak web sitelerine eri\u015fmesini sa\u011flar. DNS olmadan, her web sitesine eri\u015fmek i\u00e7in say\u0131sal IP adreslerini hat\u0131rlamak zorunda kal\u0131rd\u0131k. <h2>DNS Sorgu Ad\u0131mlar\u0131<\/h2> DNS sorgusu yap\u0131ld\u0131\u011f\u0131nda, sistem belirli bir hiyerar\u015fi i\u00e7inde \u00e7al\u0131\u015f\u0131r. Varsay\u0131lan ayarlarda (hi\u00e7bir \u00f6zel yap\u0131land\u0131rma olmad\u0131\u011f\u0131nda) DNS sorgusu \u015fu ad\u0131mlar\u0131 izler: <h3>1. HOST Dosyas\u0131 Kontrol\u00fc<\/h3> DNS \u00e7\u00f6z\u00fcmleme s\u00fcrecinde ilk kontrol edilen yer <strong>HOST dosyas\u0131d\u0131r<\/strong>. Bu dosya, i\u015fletim sisteminde yerel olarak tutulan bir t\u00fcr \"mini DNS\" kayd\u0131 gibidir. <ul> <li>Windows'ta: <code>C:\\Windows\\System32\\drivers\\etc\\hosts<\/code><\/li> <li>Linux\/Mac: <code>\/etc\/hosts<\/code><\/li> <\/ul> E\u011fer aranan alan ad\u0131 bu dosyada tan\u0131ml\u0131ysa, sistem ba\u015fka hi\u00e7bir yere bakmadan do\u011frudan bu kayd\u0131 kullan\u0131r. Kayd\u0131n do\u011fru veya yanl\u0131\u015f olup olmad\u0131\u011f\u0131n\u0131 sorgulamaz - dosyada ne yaz\u0131yorsa onu kabul eder. \u00d6rnek bir hosts dosyas\u0131: <pre><code>127.0.0.1 localhost 192.168.1.10 fileserver.local 10.0.0.5 intranet.company.local <\/code><\/pre> <h3>2. Yerel DNS Sunucusu Sorgusu<\/h3> E\u011fer hosts dosyas\u0131nda aranan alan ad\u0131 bulunamazsa, bilgisayar kendi yap\u0131land\u0131r\u0131lm\u0131\u015f DNS sunucusuna sorgu g\u00f6nderir. Bu DNS sunucusu genellikle: <ul> <li>Ev kullan\u0131c\u0131lar\u0131 i\u00e7in ISP'nin (\u0130nternet Servis Sa\u011flay\u0131c\u0131) DNS sunucusu<\/li> <li>Kurumsal a\u011flarda yerel DNS sunucusu (Active Directory ortam\u0131nda bir Domain Controller)<\/li> <li>Manuel olarak yap\u0131land\u0131r\u0131lm\u0131\u015f bir DNS sunucusu (Google DNS 8.8.8.8 gibi)<\/li> <\/ul> <h3>3. Forwarder Kontrol (Varsay\u0131lan Ayarlarda Yok)<\/h3> Normal \u015fartlarda, yap\u0131land\u0131r\u0131lm\u0131\u015f bir DNS sunucusu, kendisinde bulunmayan kay\u0131tlar i\u00e7in \"forwarder\" (y\u00f6nlendirici) olarak tan\u0131mlanm\u0131\u015f ba\u015fka DNS sunucular\u0131na sorgu g\u00f6nderir. Ancak, varsay\u0131lan ayarlarda forwarder tan\u0131ml\u0131 olmad\u0131\u011f\u0131ndan, bu ad\u0131m atlan\u0131r. <h3>4. Root DNS Sunucular\u0131na Sorgu<\/h3> Yerel DNS sunucusu, kendi \u00f6nbelle\u011finde ve b\u00f6lgesinde sorguyu \u00e7\u00f6zemezse ve hi\u00e7bir forwarder tan\u0131mlanmam\u0131\u015fsa, sorgu \"Root DNS Sunucular\u0131\"na g\u00f6nderilir. Root DNS Sunucular\u0131: <ul> <li>\u0130nternetin en \u00fcst seviyesindeki 13 sunucu grubudur (A'dan M'ye kadar etiketlenmi\u015ftir)<\/li> <li>Fiziksel olarak 13 sunucu de\u011fil, d\u00fcnya geneline yay\u0131lm\u0131\u015f y\u00fczlerce sunucudur<\/li> <li>ICANN (Internet Corporation for Assigned Names and Numbers) taraf\u0131ndan y\u00f6netilir<\/li> <\/ul> Root DNS sunucular\u0131, sorguyu \u015fu \u015fekilde i\u015fler: <ol> <li>Alan ad\u0131n\u0131n uzant\u0131s\u0131na bakar (\u00f6rn: .com, .org, .net, .tr)<\/li> <li>Bu uzant\u0131y\u0131 y\u00f6neten TLD (Top Level Domain) sunucular\u0131n\u0131n adresini d\u00f6nd\u00fcr\u00fcr<\/li> <\/ol> <h3>5. TLD DNS Sunucular\u0131na Sorgu<\/h3> Yerel DNS sunucusu, Root DNS'ten ald\u0131\u011f\u0131 bilgilerle TLD sunucular\u0131na sorgu g\u00f6nderir. TLD sunucular\u0131: <ul> <li>.com, .org, .net, .edu, .gov gibi genel \u00fcst d\u00fczey alan adlar\u0131n\u0131<\/li> <li>.tr, .uk, .de, .jp gibi \u00fclke kodlu \u00fcst d\u00fczey alan adlar\u0131n\u0131 y\u00f6netir<\/li> <\/ul> TLD sunucusu, sorgulan alan ad\u0131n\u0131 y\u00f6neten yetkili (authoritative) DNS sunucusunun adresini d\u00f6nd\u00fcr\u00fcr. <h3>6. Yetkili DNS Sunucusuna Sorgu<\/h3> Son ad\u0131mda, yerel DNS sunucusu, TLD sunucusundan ald\u0131\u011f\u0131 bilgilerle alan ad\u0131n\u0131n yetkili DNS sunucusuna sorgu g\u00f6nderir. Yetkili DNS sunucusu: <ul> <li>Alan ad\u0131n\u0131n ger\u00e7ek IP adresini bilir ve bu bilgiyi d\u00f6nd\u00fcr\u00fcr<\/li> <li>Alan ad\u0131 sahibinin DNS kay\u0131tlar\u0131n\u0131 tutan sunucudur<\/li> <\/ul> <h2>DNS \u00d6nbelle\u011fi (Cache)<\/h2> DNS sorgular\u0131n\u0131 h\u0131zland\u0131rmak i\u00e7in, sonu\u00e7lar farkl\u0131 seviyelerde \u00f6nbelle\u011fe al\u0131n\u0131r: <ol> <li><strong>Taray\u0131c\u0131 \u00d6nbelle\u011fi<\/strong>: Taray\u0131c\u0131lar, \u00f6nceden \u00e7\u00f6z\u00fclm\u00fc\u015f DNS kay\u0131tlar\u0131n\u0131 ge\u00e7ici olarak saklar<\/li> <li><strong>\u0130\u015fletim Sistemi \u00d6nbelle\u011fi<\/strong>: Bilgisayar\u0131n\u0131z, \u00f6nceden \u00e7\u00f6z\u00fclm\u00fc\u015f DNS kay\u0131tlar\u0131n\u0131 belirli bir s\u00fcre saklar<\/li> <li><strong>Yerel DNS Sunucusu \u00d6nbelle\u011fi<\/strong>: DNS sunucular\u0131 da sorgu sonu\u00e7lar\u0131n\u0131 \u00f6nbelle\u011finde tutar<\/li> <\/ol> Windows'ta DNS \u00f6nbelle\u011fini g\u00f6r\u00fcnt\u00fclemek i\u00e7in komut isteminde <code>ipconfig \/displaydns<\/code> komutunu kullanabilirsiniz. <h2>DNS Kay\u0131t T\u00fcrleri<\/h2> DNS sisteminde farkl\u0131 ama\u00e7lara hizmet eden \u00e7e\u015fitli kay\u0131t t\u00fcrleri bulunur: <ul> <li><strong>A Kayd\u0131<\/strong>: Alan ad\u0131n\u0131 IPv4 adresine ba\u011flar<\/li> <li><strong>AAAA Kayd\u0131<\/strong>: Alan ad\u0131n\u0131 IPv6 adresine ba\u011flar<\/li> <li><strong>CNAME Kayd\u0131<\/strong>: Bir alan ad\u0131n\u0131 ba\u015fka bir alan ad\u0131na y\u00f6nlendirir (takma ad)<\/li> <li><strong>MX Kayd\u0131<\/strong>: E-posta sunucular\u0131n\u0131 tan\u0131mlar<\/li> <li><strong>TXT Kayd\u0131<\/strong>: Alan ad\u0131yla ilgili metin bilgisi sa\u011flar<\/li> <li><strong>NS Kayd\u0131<\/strong>: Alan ad\u0131n\u0131n yetkili DNS sunucular\u0131n\u0131 belirtir<\/li> <li><strong>SOA Kayd\u0131<\/strong>: Alan ad\u0131n\u0131n temel yap\u0131land\u0131rma bilgilerini i\u00e7erir<\/li> <li><strong>PTR Kayd\u0131<\/strong>: IP adresini alan ad\u0131na d\u00f6n\u00fc\u015ft\u00fcr\u00fcr (ters DNS)<\/li> <\/ul> DNS, internetin sorunsuz \u00e7al\u0131\u015fmas\u0131 i\u00e7in kritik \u00f6neme sahip altyap\u0131 bile\u015fenlerinden biridir. Hiyerar\u015fik yap\u0131s\u0131 sayesinde, milyarlarca alan ad\u0131 sorgusu her g\u00fcn h\u0131zl\u0131 ve verimli bir \u015fekilde i\u015flenir. <h2>DNS Y\u00f6netimi: Geli\u015fmi\u015f Yap\u0131land\u0131rmalar<\/h2> Bu yaz\u0131da, DNS y\u00f6netiminde s\u0131k\u00e7a kullan\u0131lan geli\u015fmi\u015f yap\u0131land\u0131rmalar\u0131 ele alaca\u011f\u0131z. Her b\u00f6l\u00fcm, belirli bir DNS \u00f6zelli\u011fini ve kullan\u0131m senaryolar\u0131n\u0131 a\u00e7\u0131klamaktad\u0131r. <h2>Reverse Lookup Zone<\/h2> Reverse Lookup Zone, IP adreslerini alan adlar\u0131na \u00e7eviren DNS b\u00f6lgesidir. Forward Lookup Zone'un tam tersi y\u00f6nde \u00e7al\u0131\u015f\u0131r. <strong>Nas\u0131l \u00c7al\u0131\u015f\u0131r:<\/strong> <ul> <li>IP adresini ters \u00e7evirir ve \".in-addr.arpa\" son ekini ekler<\/li> <li>\u00d6rne\u011fin, 192.168.1.10 adresi i\u00e7in sorgu \u015feklinde olur: 10.1.168.192.in-addr.arpa<\/li> <\/ul> <strong>Olu\u015fturma Ad\u0131mlar\u0131:<\/strong> <ol> <li>DNS Manager'da \"Reverse Lookup Zones\" klas\u00f6r\u00fcne sa\u011f t\u0131klay\u0131n<\/li> <li>\"New Zone\" se\u00e7ene\u011fini t\u0131klay\u0131n<\/li> <li>Sihirbaz\u0131 takip ederek a\u011f ID'sini girin (\u00f6rn. 192.168.1)<\/li> <li>Zone olu\u015fturulduktan sonra, PTR kay\u0131tlar\u0131 ekleyerek IP-Alan ad\u0131 e\u015fle\u015ftirmelerini tan\u0131mlay\u0131n<\/li> <\/ol> <strong>Kullan\u0131m Alanlar\u0131:<\/strong> <ul> <li>G\u00fcvenlik protokolleri ve g\u00fcnl\u00fck sistemleri<\/li> <li>Spam filtreleme (E-posta sunucular\u0131 i\u00e7in reverse DNS do\u011frulamas\u0131)<\/li> <li>A\u011f sorunlar\u0131n\u0131 giderme<\/li> <li>IP adreslerini kullan\u0131c\u0131 dostu isimlerle tan\u0131mlama<\/li> <\/ul> <h2>DNS Forwarder<\/h2> DNS Forwarder, yerel DNS sunucusunun \u00e7\u00f6zemedi\u011fi sorgular\u0131 ba\u015fka DNS sunucular\u0131na y\u00f6nlendirme mekanizmas\u0131d\u0131r. <strong>Nas\u0131l Yap\u0131land\u0131r\u0131l\u0131r:<\/strong> <ol> <li>DNS Manager'da DNS sunucusuna sa\u011f t\u0131klay\u0131n<\/li> <li>\"Properties\" se\u00e7ene\u011fini t\u0131klay\u0131n<\/li> <li>\"Forwarders\" sekmesini se\u00e7in<\/li> <li>\"Edit\" d\u00fc\u011fmesine t\u0131klay\u0131n<\/li> <li>Forwarder olarak kullan\u0131lacak DNS sunucular\u0131n\u0131n IP adreslerini ekleyin (\u00f6rn. 8.8.8.8 ve 8.8.4.4 Google DNS)<\/li> <\/ol> <strong>Avantajlar\u0131:<\/strong> <ul> <li>\u0130nternet trafi\u011fini azalt\u0131r<\/li> <li>DNS sorgular\u0131n\u0131 h\u0131zland\u0131r\u0131r<\/li> <li>G\u00fcvenlik duvar\u0131 arkas\u0131ndaki a\u011flar i\u00e7in tek \u00e7\u0131k\u0131\u015f noktas\u0131 sa\u011flar<\/li> <li>A\u011f y\u00f6netimini merkezile\u015ftirir<\/li> <\/ul> <h2>Conditional Forwarder<\/h2> Conditional Forwarder, belirli alan adlar\u0131 i\u00e7in sorgular\u0131 \u00f6zel DNS sunucular\u0131na y\u00f6nlendirme mekanizmas\u0131d\u0131r. <strong>Nas\u0131l Yap\u0131land\u0131r\u0131l\u0131r:<\/strong> <ol> <li>DNS Manager'da \"Conditional Forwarders\" klas\u00f6r\u00fcne sa\u011f t\u0131klay\u0131n<\/li> <li>\"New Conditional Forwarder\" se\u00e7ene\u011fini t\u0131klay\u0131n<\/li> <li>DNS Domain alan\u0131na y\u00f6nlendirilecek alan ad\u0131n\u0131 girin (\u00f6rn. partner.com)<\/li> <li>Master Servers alan\u0131na bu alan ad\u0131na hizmet veren DNS sunucular\u0131n\u0131n IP adreslerini ekleyin<\/li> <li>\"OK\" d\u00fc\u011fmesine t\u0131klay\u0131n<\/li> <\/ol> <strong>Kullan\u0131m Senaryolar\u0131:<\/strong> <ul> <li>\u015eirket birle\u015fmeleri veya sat\u0131n almalar\u0131<\/li> <li>\u0130\u015f ortaklar\u0131 ile DNS entegrasyonu<\/li> <li>\u00c7oklu orman (multi-forest) Active Directory yap\u0131lar\u0131<\/li> <li>Hibrit bulut ortamlar\u0131<\/li> <\/ul> <h2>Secondary Zone<\/h2> Secondary Zone, ba\u015fka bir DNS sunucusundaki zone'un salt okunur bir kopyas\u0131d\u0131r. Zone transfer mekanizmas\u0131 ile ana sunucudan veri al\u0131r. <strong>Nas\u0131l Olu\u015fturulur:<\/strong> <ol> <li>DNS Manager'da \"Forward Lookup Zones\" klas\u00f6r\u00fcne sa\u011f t\u0131klay\u0131n<\/li> <li>\"New Zone\" se\u00e7ene\u011fini t\u0131klay\u0131n<\/li> <li>\"Secondary Zone\" se\u00e7ene\u011fini i\u015faretleyin<\/li> <li>Zone ad\u0131n\u0131 girin<\/li> <li>Master DNS sunucusunun IP adresini ekleyin<\/li> <\/ol> <strong>Avantajlar\u0131:<\/strong> <ul> <li>Y\u00fck dengeleme<\/li> <li>Yedeklilik<\/li> <li>Gecikmeyi azaltma (da\u011f\u0131t\u0131k a\u011flarda)<\/li> <li>Ana DNS sunucusuna gelen trafik y\u00fck\u00fcn\u00fc azaltma<\/li> <\/ul> <h2>Active Directory Integrated Zone<\/h2> Active Directory Integrated Zone, DNS verilerini Active Directory veritaban\u0131nda saklayan \u00f6zel bir zone t\u00fcr\u00fcd\u00fcr. <strong>Nas\u0131l Olu\u015fturulur:<\/strong> <ol> <li>DNS Manager'da \"Forward Lookup Zones\" klas\u00f6r\u00fcne sa\u011f t\u0131klay\u0131n<\/li> <li>\"New Zone\" se\u00e7ene\u011fini t\u0131klay\u0131n<\/li> <li>\"Primary Zone\" se\u00e7in ve \"Store the zone in Active Directory\" se\u00e7ene\u011fini i\u015faretleyin<\/li> <li>Zone'un replikasyon kapsam\u0131n\u0131 se\u00e7in (domain, orman, uygulama b\u00f6l\u00fcm\u00fc)<\/li> <\/ol> <strong>Avantajlar\u0131:<\/strong> <ul> <li>G\u00fcvenli zone transferleri (Active Directory replikasyonu kullan\u0131l\u0131r)<\/li> <li>Multi-master g\u00fcncellemeleri (herhangi bir DC \u00fczerinden g\u00fcncellenebilir)<\/li> <li>Daha iyi hata tolerans\u0131<\/li> <li>Active Directory'nin g\u00fcvenlik \u00f6zelliklerinden yararlanma<\/li> <li>Dinamik g\u00fcncellemeler i\u00e7in daha g\u00fc\u00e7l\u00fc destek<\/li> <\/ul> <h2>Best Practices ve \u00d6neriler<\/h2> <ol> <li><strong>D\u00fczenli Bak\u0131m:<\/strong> <ul> <li>DNS kay\u0131tlar\u0131n\u0131 d\u00fczenli olarak temizleyin<\/li> <li>Kullan\u0131lmayan kay\u0131tlar\u0131 silin<\/li> <li>DNS performans\u0131n\u0131 izleyin<\/li> <\/ul> <\/li> <li><strong>G\u00fcvenlik \u00d6nlemleri:<\/strong> <ul> <li>Zone transferlerini sadece g\u00fcvenilir sunuculara izin verin<\/li> <li>DNS sunucular\u0131n\u0131 g\u00fcvenlik duvar\u0131 ile koruyun<\/li> <li>DNSSEC gibi g\u00fcvenlik uzant\u0131lar\u0131n\u0131 de\u011ferlendirin<\/li> <\/ul> <\/li> <li><strong>Yedekleme Stratejisi:<\/strong> <ul> <li>DNS yap\u0131land\u0131rmas\u0131n\u0131 d\u00fczenli olarak yedekleyin<\/li> <li>Felaket kurtarma plan\u0131n\u0131za DNS'i dahil edin<\/li> <\/ul> <\/li> <li><strong>Performans \u0130yile\u015ftirmeleri:<\/strong> <ul> <li>Eski kay\u0131tlar\u0131 temizleyin<\/li> <li>DNS \u00f6nbelle\u011fini optimize edin<\/li> <li>Y\u00fck dengeleme i\u00e7in secondary zone'lar\u0131 kullan\u0131n<\/li> <\/ul> <\/li> <\/ol> DNS, modern a\u011f altyap\u0131s\u0131n\u0131n kritik bir bile\u015fenidir. Do\u011fru yap\u0131land\u0131r\u0131lm\u0131\u015f DNS, a\u011f performans\u0131n\u0131 art\u0131r\u0131r, y\u00f6netim y\u00fck\u00fcn\u00fc azalt\u0131r ve kullan\u0131c\u0131 deneyimini iyile\u015ftirir. Bu geli\u015fmi\u015f DNS yap\u0131land\u0131rmalar\u0131n\u0131 kullanarak, organizasyonunuzun ihtiya\u00e7lar\u0131na g\u00f6re \u00f6zelle\u015ftirilmi\u015f ve optimize edilmi\u015f bir DNS altyap\u0131s\u0131 olu\u015fturabilirsiniz.","excerpt":"DNS (Domain Name System), internet \u00fczerindeki alan adlar\u0131n\u0131 (www.ondernet.net gibi) IP adreslerine (142.250.190.14 gibi) \u00e7eviren sistemdir. Bu...","created_at":"2025-04-02 21:58:20","updated_at":"2026-09-08 00:26:13","category_id":8,"view_count":697,"reading_time":8,"status":"published","editor_choice":0,"is_editor_choice":0,"published_at":"2025-04-02 21:58:20","featured_image":"resimyok.jpg","slug":"dns-domain-name-system-calisma-prensipleri","category_name":"Active Directory \/Azure","category_slug":"active-directory-azure","category_color":"#f59e0b"}