{"id":11333,"date":"2023-08-25T00:00:00","date_gmt":"2023-08-25T00:00:00","guid":{"rendered":"https:\/\/tech-lib.eu\/tech\/jak-funguje-dns\/"},"modified":"2023-08-25T00:00:00","modified_gmt":"2023-08-25T00:00:00","slug":"jak-funguje-dns","status":"publish","type":"post","link":"https:\/\/tech-lib.eu\/tech\/jak-funguje-dns\/","title":{"rendered":"Jak funguje DNS?"},"content":{"rendered":"
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What is DNS What is a DNS server?<\/div>\n
DNS, or the Domain Name System, translates human readable domain names (for example, www.amazon.com) to machine readable IP addresses (for example, 192.0. 2.44).<\/div>\n
\n\t\t\t\t\t Dal\u0161\u00ed informace najdete na<\/span> aws.amazon.com<\/a>\n\t\t\t\t<\/div>\n<\/p><\/div>\n
U\u017eivatel\u00e9 internetu mohou nav\u0161t\u011bvovat webov\u00e9 str\u00e1nky pomoc\u00ed syst\u00e9mu DNS (Domain Name System), kter\u00fd p\u0159ev\u00e1d\u00ed lidsky \u010diteln\u00e9 n\u00e1zvy dom\u00e9n na strojov\u011b \u010diteln\u00e9 IP adresy. DNS v podstat\u011b slou\u017e\u00ed jako internetov\u00e1 obdoba telefonn\u00edho seznamu a umo\u017e\u0148uje vyhled\u00e1vat webov\u00e9 str\u00e1nky a dal\u0161\u00ed online zdroje a p\u0159ipojovat se k nim. Abyste pochopili z\u00e1klady p\u0159ipojen\u00ed k internetu, mus\u00edte zn\u00e1t, jak DNS funguje. <\/p>\n
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Pro fungov\u00e1n\u00ed syst\u00e9mu DNS jsou nezbytn\u00e9 servery DNS. Tyto servery maj\u00ed na starosti \u00fadr\u017ebu a \u0161\u00ed\u0159en\u00ed obrovsk\u00e9 datab\u00e1ze dom\u00e9nov\u00fdch jmen a s nimi spojen\u00fdch IP adres. Dotaz DNS je odesl\u00e1n webov\u00fdm prohl\u00ed\u017ee\u010dem u\u017eivatele na server DNS, kdy\u017e zad\u00e1 n\u00e1zev dom\u00e9ny, aby jej p\u0159evedl na IP adresu. Server DNS n\u00e1sledn\u011b vr\u00e1t\u00ed IP adresu a umo\u017en\u00ed prohl\u00ed\u017ee\u010di p\u0159ipojit se k po\u017eadovan\u00e9 webov\u00e9 str\u00e1nce. <\/p>\n

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D\u00edky milion\u016fm server\u016f DNS rozm\u00edst\u011bn\u00fdch po cel\u00e9m sv\u011bt\u011b funguje syst\u00e9m DNS v distribuovan\u00e9m syst\u00e9mu po cel\u00e9m internetu. Strom DNS nebo hierarchie DNS je n\u00e1zev pro hierarchick\u00fd r\u00e1mec, ve kter\u00e9m jsou tyto servery uspo\u0159\u00e1d\u00e1ny. Na vrcholu hierarchie jsou ko\u0159enov\u00e9 servery DNS, kter\u00e9 uchov\u00e1vaj\u00ed \u00fadaje o dom\u00e9n\u00e1ch nejvy\u0161\u0161\u00ed \u00farovn\u011b (TLD), jako jsou.com,.org a.net, a tak\u00e9 o TLD s k\u00f3dem zem\u011b, jako je.uk nebo.jp. Tento \u00fakol maj\u00ed na starosti servery TLD, kter\u00e9 se nach\u00e1zej\u00ed za ko\u0159enov\u00fdmi servery a maj\u00ed na starosti uchov\u00e1v\u00e1n\u00ed dat o konkr\u00e9tn\u00edch dom\u00e9nov\u00fdch koncovk\u00e1ch, jako je.com nebo.org. <\/p>\n

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Kdy\u017e server DNS obdr\u017e\u00ed dotaz na dom\u00e9nov\u00e9 jm\u00e9no, prov\u00e1d\u00ed t\u0159i z\u00e1kladn\u00ed f\u00e1ze jeho \u0159e\u0161en\u00ed. Server DNS nejprve zjist\u00ed, zda je IP adresa z p\u0159edchoz\u00edho dotazu uchov\u00e1na v jeho m\u00edstn\u00ed mezipam\u011bti. Pokud je IP adresa nalezena, je okam\u017eit\u011b vr\u00e1cena, co\u017e urychluje postup \u0159e\u0161en\u00ed. Za druh\u00e9 server DNS kontaktuje ostatn\u00ed servery DNS v hierarchii, aby zjistil po\u017eadovan\u00e9 informace, pokud nen\u00ed IP adresa nalezena v m\u00edstn\u00ed mezipam\u011bti. Dokud nen\u00ed IP adresa nalezena, tento proces se opakuje. <\/p>\n

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Vr\u00e1cen\u00ed IP adresy \u017e\u00e1daj\u00edc\u00edmu klientovi je posledn\u00edm krokem v postupu \u0159e\u0161en\u00ed DNS. Prohl\u00ed\u017ee\u010d klienta se m\u016f\u017ee p\u0159ipojit p\u0159\u00edmo k serveru hostuj\u00edc\u00edmu webovou str\u00e1nku t\u00edm, \u017ee obdr\u017e\u00ed IP adresu od serveru DNS, kter\u00e1 je zasl\u00e1na zp\u011bt klientovi. U\u017eivatel m\u00e1 p\u0159\u00edstup k po\u017eadovan\u00e9mu obsahu d\u00edky schopnosti tohoto spojen\u00ed p\u0159en\u00e1\u0161et data mezi klientem a webovou str\u00e1nkou. <\/p>\n

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Na z\u00e1v\u011br je t\u0159eba poznamenat, \u017ee syst\u00e9m DNS m\u00e1 z\u00e1sadn\u00ed v\u00fdznam pro p\u0159evod dom\u00e9nov\u00fdch jmen na IP adresy, co\u017e u\u017eivatel\u016fm umo\u017e\u0148uje p\u0159\u00edstup k webov\u00fdm str\u00e1nk\u00e1m a online slu\u017eb\u00e1m. Informace pot\u0159ebn\u00e9 pro podporu tohoto procesu p\u0159evodu ukl\u00e1daj\u00ed a poskytuj\u00ed servery DNS, kter\u00e9 jsou rozpt\u00fdleny po cel\u00e9m internetu. Servery DNS zaji\u0161\u0165uj\u00ed, aby se u\u017eivatel\u00e9 mohli p\u0159ipojit k p\u0159\u00edslu\u0161n\u00fdm IP adres\u00e1m odpov\u00eddaj\u00edc\u00edm jejich po\u017eadovan\u00fdm dom\u00e9nov\u00fdm jm\u00e9n\u016fm, a to pomoc\u00ed hierarchick\u00e9 struktury a \u0159ady postup\u016f. Znalost fungov\u00e1n\u00ed DNS v\u00e1m pom\u016f\u017ee l\u00e9pe pochopit z\u00e1kladn\u00ed procesy, kter\u00e9 umo\u017e\u0148uj\u00ed bezprobl\u00e9mov\u00e9 p\u0159ipojen\u00ed k internetu.<\/p><\/div>\n

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FAQ<\/div>\n
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Je IPv4 moje IP adresa?<\/div>\n

Ne, va\u0161e IP adresa nen\u00ed v IPv4. K identifikaci za\u0159\u00edzen\u00ed v s\u00edti pou\u017e\u00edv\u00e1 protokol IPv4 (Internet Protocol verze 4) \u010d\u00edselnou metodu adresov\u00e1n\u00ed. Ta p\u0159id\u011bluje ka\u017ed\u00e9mu za\u0159\u00edzen\u00ed p\u0159ipojen\u00e9mu k internetu speci\u00e1ln\u00ed IP adresu. Va\u0161emu za\u0159\u00edzen\u00ed byla v r\u00e1mci adresovac\u00edho sch\u00e9matu IPv4 p\u0159id\u011blena jedine\u010dn\u00e1 adresa zvan\u00e1 IP adresa. <\/p>\n<\/div>\n

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Kde se nach\u00e1zej\u00ed servery DNS?<\/div>\n

Existuje mnoho m\u00edst, kde se nach\u00e1zej\u00ed servery DNS. Ko\u0159enov\u00e9 servery, servery dom\u00e9n nejvy\u0161\u0161\u00ed \u00farovn\u011b (TLD) a autoritativn\u00ed jmenn\u00e9 servery jsou t\u0159i z\u00e1kladn\u00ed kategorie server\u016f DNS. <\/p>\n

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Hierarchie DNS je zalo\u017eena na 13 sad\u00e1ch ko\u0159enov\u00fdch server\u016f, kter\u00e9 jsou rozpt\u00fdleny po cel\u00e9m sv\u011bt\u011b. Tyto servery poskytuj\u00ed podrobn\u00e9 informace o um\u00edst\u011bn\u00ed server\u016f TLD. <\/p>\n

<\/div>\n

Servery TLD spravuj\u00ed n\u00e1zvy dom\u00e9n nejvy\u0161\u0161\u00ed \u00farovn\u011b, jako jsou.com,.org a.net, jak ji\u017e n\u00e1zev napov\u00edd\u00e1. Ka\u017ed\u00e1 TLD m\u00e1 jedine\u010dnou sb\u00edrku server\u016f, kter\u00e9 mohou b\u00fdt rozm\u00edst\u011bny v r\u016fzn\u00fdch zem\u00edch. <\/p>\n

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Na druh\u00e9 stran\u011b autoritativn\u00ed jmenn\u00e9 servery maj\u00ed na starosti konkr\u00e9tn\u00ed dom\u00e9nov\u00e1 jm\u00e9na. Jsou na nich ulo\u017eeny IP adresy spojen\u00e9 s dom\u00e9nov\u00fdmi jm\u00e9ny a spravuj\u00ed je vlastn\u00edci dom\u00e9n nebo hostingov\u00e9 spole\u010dnosti. <\/p>\n

<\/div>\n

Obecn\u011b jsou servery DNS rozpt\u00fdleny po cel\u00e9m sv\u011bt\u011b, aby bylo zaru\u010deno rychl\u00e9 a d\u016fv\u011bryhodn\u00e9 rozli\u0161en\u00ed dom\u00e9nov\u00fdch jmen pro z\u00e1kazn\u00edky na cel\u00e9m sv\u011bt\u011b. <\/p>\n<\/div>\n

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Jak\u00fd je protokol DNS?<\/div>\n

Protokol TCP (Transmission Control Protocol) a protokol UDP (User Datagram Protocol) jsou dva z\u00e1kladn\u00ed protokoly, kter\u00e9 syst\u00e9m DNS (Domain Name System) pou\u017e\u00edv\u00e1 ke sv\u00e9mu fungov\u00e1n\u00ed. Zat\u00edmco v\u011bt\u0161ina dotaz\u016f a odpov\u011bd\u00ed DNS vyu\u017e\u00edv\u00e1 protokol UDP, proto\u017ee je rychlej\u0161\u00ed a efektivn\u011bj\u0161\u00ed pro jednoduch\u00e9 po\u017eadavky, p\u0159enosy z\u00f3n a v\u011bt\u0161\u00ed datov\u00e9 p\u0159enosy pou\u017e\u00edvaj\u00ed m\u00edsto toho protokol TCP. <\/p>\n<\/div>\n

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Kde je ulo\u017een syst\u00e9m DNS?<\/div>\n

Syst\u00e9m DNS (Domain Name System) je distribuovan\u00fd datab\u00e1zov\u00fd syst\u00e9m, kter\u00fd p\u0159ev\u00e1d\u00ed n\u00e1zvy dom\u00e9n (nap\u0159\u00edklad www.example.com) na IP adresy (nap\u0159\u00edklad 192.0.2.1), aby umo\u017enil komunikaci mezi po\u010d\u00edta\u010di na internetu. Syst\u00e9m DNS je rozpt\u00fdlen na mnoha serverech po cel\u00e9m sv\u011bt\u011b a nen\u00ed uchov\u00e1v\u00e1n na jednom centr\u00e1ln\u00edm m\u00edst\u011b. <\/p>\n

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Hierarchii DNS tvo\u0159\u00ed r\u016fzn\u00e9 typy server\u016f DNS, z nich\u017e ka\u017ed\u00fd m\u00e1 specifickou funkci. Na vrcholu hierarchie jsou ko\u0159enov\u00e9 servery, na kter\u00fdch jsou ulo\u017eena data pro dom\u00e9ny nejvy\u0161\u0161\u00ed \u00farovn\u011b (TLD), jako jsou.com,.org,.net atd. Tyto ko\u0159enov\u00e9 servery poskytuj\u00ed pouze informace o tom, kde lze naj\u00edt autoritativn\u00ed servery DNS pro jednotliv\u00e9 dom\u00e9ny nejvy\u0161\u0161\u00ed \u00farovn\u011b, nikoli celou datab\u00e1zi DNS. <\/p>\n

<\/div>\n

Servery TLD se nach\u00e1zej\u00ed pod ko\u0159enov\u00fdmi servery a uchov\u00e1vaj\u00ed \u00fadaje t\u00fdkaj\u00edc\u00ed se konkr\u00e9tn\u00edch TLD, kter\u00e9 maj\u00ed na starosti. Nap\u0159\u00edklad server TLD.com uchov\u00e1v\u00e1 \u00fadaje o n\u00e1zvech dom\u00e9n kon\u010d\u00edc\u00edch na.com. <\/p>\n

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Autoritativn\u00ed servery DNS, kter\u00e9 se nach\u00e1zej\u00ed n\u00ed\u017ee v hierarchii, uchov\u00e1vaj\u00ed z\u00e1znamy DNS jednotliv\u00fdch dom\u00e9nov\u00fdch jmen. Ur\u010den\u00fd autoritativn\u00ed server DNS pro ka\u017ed\u00e9 dom\u00e9nov\u00e9 jm\u00e9no m\u00e1 na starosti \u00fadr\u017ebu jeho dat DNS. <\/p>\n

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Za \u00fa\u010delem zv\u00fd\u0161en\u00ed produktivity a sn\u00ed\u017een\u00ed z\u00e1t\u011b\u017ee hierarchie DNS mohou poskytovatel\u00e9 internetov\u00fdch slu\u017eeb (ISP) a organizace tak\u00e9 z\u0159\u00eddit vlastn\u00ed servery DNS, kter\u00e9 ukl\u00e1daj\u00ed z\u00e1znamy DNS do mezipam\u011bti. Doba \u017eivota (TTL) je doba, po kterou tyto servery uchov\u00e1vaj\u00ed \u010dasto nav\u0161t\u011bvovan\u00e1 data DNS. <\/p>\n

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Syst\u00e9m DNS je rozd\u011blen na mnoho server\u016f, v\u010detn\u011b ko\u0159enov\u00fdch server\u016f, server\u016f TLD, autoritativn\u00edch server\u016f DNS a server\u016f mezipam\u011bti provozovan\u00fdch poskytovateli internetov\u00fdch slu\u017eeb a organizacemi.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

What is DNS What is a DNS server? DNS, or the Domain Name System, translates human readable domain names (for example, www.amazon.com) to machine readable IP addresses (for example, 192.0. 2.44). Dal\u0161\u00ed informace najdete na aws.amazon.com U\u017eivatel\u00e9 internetu mohou nav\u0161t\u011bvovat webov\u00e9 str\u00e1nky pomoc\u00ed syst\u00e9mu DNS (Domain Name System), kter\u00fd p\u0159ev\u00e1d\u00ed lidsky \u010diteln\u00e9 n\u00e1zvy dom\u00e9n na … \u010c\u00edst d\u00e1l<\/a><\/p>\n","protected":false},"author":4429,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[33],"tags":[],"class_list":["post-11333","post","type-post","status-publish","format-standard","hentry","category-networking"],"_links":{"self":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/11333","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/users\/4429"}],"replies":[{"embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/comments?post=11333"}],"version-history":[{"count":0,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/posts\/11333\/revisions"}],"wp:attachment":[{"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/media?parent=11333"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/categories?post=11333"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tech-lib.eu\/tech\/wp-json\/wp\/v2\/tags?post=11333"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}