{"id":16738,"date":"2025-04-29T15:33:32","date_gmt":"2025-04-29T08:33:32","guid":{"rendered":"https:\/\/interdata.vn\/blog\/?p=16738"},"modified":"2025-04-29T15:37:07","modified_gmt":"2025-04-29T08:37:07","slug":"dns-la-gi","status":"publish","type":"post","link":"https:\/\/interdata.vn\/blog\/dns-la-gi\/","title":{"rendered":"DNS l\u00e0 g\u00ec? \u0110\u1ecbnh ngh\u0129a, C\u00e1ch ho\u1ea1t \u0111\u1ed9ng &#038; Vai tr\u00f2 (D\u1ec5 hi\u1ec3u)"},"content":{"rendered":"<p>B\u1ea1n c\u00f3 bao gi\u1edd th\u1eafc m\u1eafc l\u00e0m th\u1ebf n\u00e0o ch\u1ec9 c\u1ea7n g\u00f5 <code>google.com<\/code> v\u00e0o tr\u00ecnh duy\u1ec7t l\u00e0 c\u00f3 th\u1ec3 truy c\u1eadp \u0111\u01b0\u1ee3c Google, thay v\u00ec ph\u1ea3i nh\u1edb m\u1ed9t d\u00e3y s\u1ed1 ph\u1ee9c t\u1ea1p? B\u00ed m\u1eadt \u0111\u1eb1ng sau s\u1ef1 ti\u1ec7n l\u1ee3i n\u00e0y ch\u00ednh l\u00e0 <strong>DNS<\/strong>. B\u00e0i vi\u1ebft n\u00e0y s\u1ebd gi\u1ea3i th\u00edch <strong>DNS l\u00e0 g\u00ec<\/strong> m\u1ed9t c\u00e1ch d\u1ec5 hi\u1ec3u nh\u1ea5t, kh\u00e1m ph\u00e1 <strong>c\u00e1ch ho\u1ea1t \u0111\u1ed9ng<\/strong> v\u00e0 <strong>vai tr\u00f2<\/strong> kh\u00f4ng th\u1ec3 thi\u1ebfu c\u1ee7a n\u00f3 trong th\u1ebf gi\u1edbi Internet.<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 counter-hierarchy ez-toc-counter ez-toc-white ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">N\u1ed8I DUNG<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-toggle-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#DNS-la-gi\" >DNS l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Tai-sao-chung-ta-can-DNS-Vai-tro-cua-DNS-la-gi\" >T\u1ea1i sao ch\u00fang ta c\u1ea7n DNS? Vai tr\u00f2 c\u1ee7a DNS l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#DNS-hoat-dong-nhu-the-nao\" >DNS ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Cac-buoc-chinh-trong-quy-trinh-phan-giai-DNS\" >C\u00e1c b\u01b0\u1edbc ch\u00ednh trong quy tr\u00ecnh ph\u00e2n gi\u1ea3i DNS<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Vi-du-minh-hoa-thuc-te\" >V\u00ed d\u1ee5 minh h\u1ecda th\u1ef1c t\u1ebf<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Cac-thanh-phan-chinh-trong-he-thong-DNS\" >C\u00e1c th\u00e0nh ph\u1ea7n ch\u00ednh trong h\u1ec7 th\u1ed1ng DNS<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#DNS-Resolver-Trinh-phan-giai-DNS-May-chu-DNS-de-quy\" >DNS Resolver (Tr\u00ecnh ph\u00e2n gi\u1ea3i DNS \/ M\u00e1y ch\u1ee7 DNS \u0111\u1ec7 quy)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Root-Name-Server-May-chu-ten-mien-goc\" >Root Name Server (M\u00e1y ch\u1ee7 t\u00ean mi\u1ec1n g\u1ed1c)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#TLD-Name-Server-May-chu-ten-mien-cap-cao-nhat\" >TLD Name Server (M\u00e1y ch\u1ee7 t\u00ean mi\u1ec1n c\u1ea5p cao nh\u1ea5t)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Authoritative-Name-Server-May-chu-ten-mien-co-tham-quyen\" >Authoritative Name Server (M\u00e1y ch\u1ee7 t\u00ean mi\u1ec1n c\u00f3 th\u1ea9m quy\u1ec1n)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Ban-ghi-DNS-DNS-Records\" >B\u1ea3n ghi DNS (DNS Records)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Cac-loai-ban-ghi-DNS-DNS-Records-pho-bien-nhat\" >C\u00e1c lo\u1ea1i b\u1ea3n ghi DNS (DNS Records) ph\u1ed5 bi\u1ebfn nh\u1ea5t<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Ban-ghi-A-Address-Mapping\" >B\u1ea3n ghi A (Address Mapping)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Ban-ghi-AAAA-IPv6-Address-Mapping\" >B\u1ea3n ghi AAAA (IPv6 Address Mapping)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Ban-ghi-CNAME-Canonical-Name\" >B\u1ea3n ghi CNAME (Canonical Name)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Ban-ghi-MX-Mail-Exchanger\" >B\u1ea3n ghi MX (Mail Exchanger)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Ban-ghi-TXT-Text-Record\" >B\u1ea3n ghi TXT (Text Record)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Ban-ghi-NS-Name-Server\" >B\u1ea3n ghi NS (Name Server)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Cac-loai-May-chu-DNS-DNS-Server\" >C\u00e1c lo\u1ea1i M\u00e1y ch\u1ee7 DNS (DNS Server)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#DNS-Server-cua-Nha-cung-cap-Internet-ISP-DNS\" >DNS Server c\u1ee7a Nh\u00e0 cung c\u1ea5p Internet (ISP DNS)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Public-DNS-Server-May-chu-DNS-cong-cong\" >Public DNS Server (M\u00e1y ch\u1ee7 DNS c\u00f4ng c\u1ed9ng)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Private-DNS-Server-May-chu-DNS-rieng-tu\" >Private DNS Server (M\u00e1y ch\u1ee7 DNS ri\u00eang t\u01b0)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Huong-dan-Cach-thay-doi-DNS-Server-Doi-DNS\" >H\u01b0\u1edbng d\u1eabn C\u00e1ch thay \u0111\u1ed5i DNS Server (\u0110\u1ed5i DNS)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Thay-doi-DNS-tren-may-tinh-Windows-1011\" >Thay \u0111\u1ed5i DNS tr\u00ean m\u00e1y t\u00ednh Windows (10\/11)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Thay-doi-DNS-tren-may-tinh-macOS\" >Thay \u0111\u1ed5i DNS tr\u00ean m\u00e1y t\u00ednh macOS<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Thay-doi-DNS-tren-dien-thoai-Android\" >Thay \u0111\u1ed5i DNS tr\u00ean \u0111i\u1ec7n tho\u1ea1i Android<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Thay-doi-DNS-tren-iPhoneiPad-iOS\" >Thay \u0111\u1ed5i DNS tr\u00ean iPhone\/iPad (iOS)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Mot-so-khai-niem-DNS-quan-trong-khac-can-biet\" >M\u1ed9t s\u1ed1 kh\u00e1i ni\u1ec7m DNS quan tr\u1ecdng kh\u00e1c c\u1ea7n bi\u1ebft<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-29\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#DNS-Propagation-Su-lan-truyenCap-nhat-DNS\" >DNS Propagation (S\u1ef1 lan truy\u1ec1n\/C\u1eadp nh\u1eadt DNS)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-30\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#DNS-Cache-Bo-nho-dem-DNS\" >DNS Cache (B\u1ed9 nh\u1edb \u0111\u1ec7m DNS)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-31\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#TTL-Time-To-Live\" >TTL (Time To Live)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-32\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Cau-hoi-thuong-gap-ve-DNS-FAQ\" >C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p v\u1ec1 DNS (FAQ)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-33\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Thay-doi-DNS-co-lam-tang-toc-do-mang-khong\" >Thay \u0111\u1ed5i DNS c\u00f3 l\u00e0m t\u0103ng t\u1ed1c \u0111\u1ed9 m\u1ea1ng kh\u00f4ng?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-34\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Dung-DNS-cua-Google-8888-hay-Cloudflare-1111-tot-hon\" >D\u00f9ng DNS c\u1ee7a Google (8.8.8.8) hay Cloudflare (1.1.1.1) t\u1ed1t h\u01a1n?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-35\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Doi-DNS-co-giup-truy-cap-web-bi-chan-khong\" >\u0110\u1ed5i DNS c\u00f3 gi\u00fap truy c\u1eadp web b\u1ecb ch\u1eb7n kh\u00f4ng?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-36\" href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/#Loi-%E2%80%9CDNS-server-isnt-responding%E2%80%9D-nghia-la-gi-Cach-sua\" >L\u1ed7i &#8220;DNS server isn&#8217;t responding&#8221; ngh\u0129a l\u00e0 g\u00ec? C\u00e1ch s\u1eeda?<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"DNS-la-gi\"><\/span>DNS l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/\"><strong>DNS<\/strong><\/a> l\u00e0 vi\u1ebft t\u1eaft c\u1ee7a <strong>Domain Name System<\/strong>, d\u1ecbch ra ti\u1ebfng Vi\u1ec7t l\u00e0 <strong>H\u1ec7 th\u1ed1ng ph\u00e2n gi\u1ea3i <a href=\"https:\/\/interdata.vn\/blog\/domain-la-gi\/\">t\u00ean mi\u1ec1n<\/a><\/strong>. V\u1ec1 c\u01a1 b\u1ea3n, n\u00f3 ho\u1ea1t \u0111\u1ed9ng nh\u01b0 m\u1ed9t ng\u01b0\u1eddi phi\u00ean d\u1ecbch kh\u1ed5ng l\u1ed3 cho Internet, chuy\u00ean chuy\u1ec3n \u0111\u1ed5i <strong>t\u00ean mi\u1ec1n<\/strong> (v\u00ed d\u1ee5: <code>google.com<\/code>) m\u00e0 con ng\u01b0\u1eddi d\u1ec5 nh\u1edb th\u00e0nh <strong><a href=\"https:\/\/interdata.vn\/blog\/dia-chi-ip-la-gi\/\">\u0111\u1ecba ch\u1ec9 IP<\/a><\/strong> d\u1ea1ng s\u1ed1 (v\u00ed d\u1ee5: <code>172.217.160.142<\/code>) m\u00e0 m\u00e1y t\u00ednh d\u00f9ng \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh v\u1ecb tr\u00ed c\u1ee7a nhau.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS.jpg\" alt=\"Domain Name System (DNS)\" width=\"750\" height=\"500\" class=\"aligncenter size-full wp-image-27727\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS.jpg 750w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-300x200.jpg 300w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<p>Con ng\u01b0\u1eddi ch\u00fang ta r\u1ea5t gi\u1ecfi <strong>ghi nh\u1edb<\/strong> t\u00ean g\u1ecdi, v\u00ed d\u1ee5 nh\u01b0 t\u00ean c\u00e1c <strong><a href=\"https:\/\/interdata.vn\/blog\/website-la-gi\/\">website<\/a><\/strong> quen thu\u1ed9c nh\u01b0 <code>facebook.com<\/code> hay <code>vnexpress.net<\/code>. Tuy nhi\u00ean, m\u00e1y t\u00ednh v\u00e0 c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng l\u1ea1i &#8220;n\u00f3i chuy\u1ec7n&#8221; v\u1edbi nhau b\u1eb1ng c\u00e1c <strong>\u0111\u1ecba ch\u1ec9 IP<\/strong> (Internet Protocol Address) \u2013 nh\u1eefng d\u00e3y s\u1ed1 nh\u01b0 <code>142.250.204.110<\/code> \u2013 v\u1ed1n r\u1ea5t kh\u00f3 \u0111\u1ec3 ch\u00fang ta nh\u1edb h\u1ebft.<\/p>\n<p><strong>H\u1ec7 th\u1ed1ng ph\u00e2n gi\u1ea3i t\u00ean mi\u1ec1n<\/strong> (DNS) \u0111\u01b0\u1ee3c t\u1ea1o ra ch\u00ednh l\u00e0 \u0111\u1ec3 l\u00e0m c\u1ea7u n\u1ed1i cho s\u1ef1 kh\u00e1c bi\u1ec7t n\u00e0y. N\u00f3 gi\u00fap ch\u00fang ta kh\u00f4ng c\u1ea7n ph\u1ea3i b\u1eadn t\u00e2m \u0111\u1ebfn nh\u1eefng d\u00e3y s\u1ed1 IP ph\u1ee9c t\u1ea1p kia. Thay v\u00e0o \u0111\u00f3, b\u1ea1n ch\u1ec9 c\u1ea7n nh\u1eadp t\u00ean mi\u1ec1n th\u00e2n thi\u1ec7n v\u00e0o <strong>tr\u00ecnh duy\u1ec7t web<\/strong> l\u00e0 \u0111\u1ee7.<\/p>\n<p>C\u00e1ch v\u00ed von d\u1ec5 hi\u1ec3u nh\u1ea5t l\u00e0 xem DNS <strong>v\u00ed nh\u01b0<\/strong> m\u1ed9t cu\u1ed1n <strong>danh b\u1ea1 \u0111i\u1ec7n tho\u1ea1i<\/strong> kh\u1ed5ng l\u1ed3 v\u00e0 li\u00ean t\u1ee5c c\u1eadp nh\u1eadt c\u1ee7a <strong>Internet<\/strong>. Khi b\u1ea1n mu\u1ed1n g\u1ecdi ai \u0111\u00f3, b\u1ea1n t\u00ecm t\u00ean trong danh b\u1ea1 \u0111\u1ec3 l\u1ea5y s\u1ed1 \u0111i\u1ec7n tho\u1ea1i. T\u01b0\u01a1ng t\u1ef1, khi b\u1ea1n g\u00f5 <strong>t\u00ean mi\u1ec1n<\/strong> (<code>facebook.com<\/code>), DNS s\u1ebd <strong>t\u00ecm ki\u1ebfm<\/strong> v\u00e0 tr\u1ea3 v\u1ec1 <strong>\u0111\u1ecba ch\u1ec9 IP<\/strong> t\u01b0\u01a1ng \u1ee9ng c\u1ee7a m\u00e1y ch\u1ee7 Facebook.<\/p>\n<p>\u0110\u1ec3 r\u00f5 h\u01a1n, <strong>T\u00ean mi\u1ec1n (Domain Name)<\/strong> l\u00e0 t\u00ean \u0111\u1ecbnh danh duy nh\u1ea5t c\u1ee7a m\u1ed9t <strong>website<\/strong> b\u1eb1ng ch\u1eef, d\u1ec5 \u0111\u1ecdc, d\u1ec5 nh\u1edb (v\u00ed d\u1ee5: <code>example.com<\/code>). C\u00f2n <strong>\u0110\u1ecba ch\u1ec9 IP (IP Address)<\/strong> l\u00e0 m\u1ed9t \u0111\u1ecba ch\u1ec9 s\u1ed1 duy nh\u1ea5t (nh\u01b0 <code>192.168.1.1<\/code> ho\u1eb7c <code>2001:db8::1<\/code>) \u0111\u01b0\u1ee3c g\u00e1n cho m\u1ed7i m\u00e1y ch\u1ee7 ho\u1eb7c thi\u1ebft b\u1ecb k\u1ebft n\u1ed1i v\u00e0o <strong><a href=\"https:\/\/interdata.vn\/blog\/mang-internet\/\">m\u1ea1ng Internet<\/a><\/strong> \u0111\u1ec3 nh\u1eadn di\u1ec7n.<\/p>\n<p>Nh\u01b0 v\u1eady, DNS \u0111\u00f3ng <strong>vai tr\u00f2 quan tr\u1ecdng<\/strong> v\u00e0 l\u00e0 m\u1ed9t ph\u1ea7n kh\u00f4ng th\u1ec3 thi\u1ebfu c\u1ee7a h\u1ea1 t\u1ea7ng <strong>Internet<\/strong>. N\u1ebfu kh\u00f4ng c\u00f3 DNS, vi\u1ec7c <strong>truy c\u1eadp website<\/strong> h\u00e0ng ng\u00e0y c\u1ee7a ch\u00fang ta s\u1ebd tr\u1edf n\u00ean v\u00f4 c\u00f9ng b\u1ea5t ti\u1ec7n v\u00e0 ph\u1ee9c t\u1ea1p, \u0111\u00f2i h\u1ecfi ph\u1ea3i nh\u1edb ch\u00ednh x\u00e1c h\u00e0ng lo\u1ea1t <strong>\u0111\u1ecba ch\u1ec9 IP<\/strong>.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Tai-sao-chung-ta-can-DNS-Vai-tro-cua-DNS-la-gi\"><\/span>T\u1ea1i sao ch\u00fang ta c\u1ea7n DNS? Vai tr\u00f2 c\u1ee7a DNS l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-01.jpg\" alt=\"Domain Name System (DNS) 01\" width=\"750\" height=\"344\" class=\"aligncenter size-full wp-image-27721\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-01.jpg 750w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-01-300x138.jpg 300w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<p>Vai tr\u00f2 c\u1ed1t l\u00f5i v\u00e0 quan tr\u1ecdng nh\u1ea5t c\u1ee7a DNS l\u00e0 gi\u00fap \u0111\u01a1n gi\u1ea3n h\u00f3a tr\u1ea3i nghi\u1ec7m <strong>truy c\u1eadp Internet<\/strong> cho con ng\u01b0\u1eddi. H\u00e3y t\u01b0\u1edfng t\u01b0\u1ee3ng n\u1ebfu kh\u00f4ng c\u00f3 DNS, b\u1ea1n s\u1ebd ph\u1ea3i nh\u1edb <strong>\u0111\u1ecba ch\u1ec9 IP<\/strong> c\u1ee7a m\u1ecdi trang web b\u1ea1n mu\u1ed1n v\u00e0o &#8211; m\u1ed9t vi\u1ec7c g\u1ea7n nh\u01b0 b\u1ea5t kh\u1ea3 thi! DNS lo\u1ea1i b\u1ecf g\u00e1nh n\u1eb7ng \u0111\u00f3.<\/p>\n<p>Nh\u1edd DNS, ch\u00fang ta ch\u1ec9 c\u1ea7n nh\u1edb nh\u1eefng <strong>t\u00ean mi\u1ec1n<\/strong> d\u1ec5 li\u00ean t\u01b0\u1edfng nh\u01b0 <code>youtube.com<\/code> hay <code>wikipedia.org<\/code>. H\u1ec7 th\u1ed1ng DNS s\u1ebd t\u1ef1 \u0111\u1ed9ng th\u1ef1c hi\u1ec7n c\u00f4ng vi\u1ec7c &#8220;d\u1ecbch&#8221; t\u00ean mi\u1ec1n n\u00e0y sang \u0111\u1ecba ch\u1ec9 IP c\u1ea7n thi\u1ebft \u0111\u1ec3 tr\u00ecnh duy\u1ec7t c\u1ee7a b\u1ea1n c\u00f3 th\u1ec3 k\u1ebft n\u1ed1i \u0111\u1ebfn \u0111\u00fang m\u00e1y ch\u1ee7 ch\u1ee9a n\u1ed9i dung web.<\/p>\n<p>Ngo\u00e0i vi\u1ec7c truy c\u1eadp web, DNS c\u00f2n l\u00e0 n\u1ec1n t\u1ea3ng cho nhi\u1ec1u d\u1ecbch v\u1ee5 quan tr\u1ecdng kh\u00e1c tr\u00ean Internet. V\u00ed d\u1ee5, khi b\u1ea1n g\u1eedi email \u0111\u1ebfn \u0111\u1ecba ch\u1ec9 <code>ten_nguoi_nhan@congty.com<\/code>, h\u1ec7 th\u1ed1ng email c\u0169ng c\u1ea7n d\u00f9ng DNS (th\u00f4ng qua b\u1ea3n ghi MX) \u0111\u1ec3 t\u00ecm ra \u0111\u1ecba ch\u1ec9 m\u00e1y ch\u1ee7 mail c\u1ee7a <code>congty.com<\/code> v\u00e0 g\u1eedi th\u01b0 \u0111\u1ebfn \u0111\u00f3.<\/p>\n<p>M\u1ed9t <strong>vai tr\u00f2 c\u1ee7a DNS<\/strong> \u00edt \u0111\u01b0\u1ee3c bi\u1ebft \u0111\u1ebfn h\u01a1n l\u00e0 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn <strong>t\u1ed1c \u0111\u1ed9 truy c\u1eadp<\/strong>. Vi\u1ec7c s\u1eed d\u1ee5ng c\u00e1c <strong>m\u00e1y ch\u1ee7 DNS<\/strong> (DNS Server) nhanh v\u00e0 \u1ed5n \u0111\u1ecbnh c\u00f3 th\u1ec3 gi\u00fap gi\u1ea3m th\u1eddi gian c\u1ea7n thi\u1ebft \u0111\u1ec3 <strong>ph\u00e2n gi\u1ea3i t\u00ean mi\u1ec1n<\/strong>, g\u00f3p ph\u1ea7n l\u00e0m trang web t\u1ea3i nhanh h\u01a1n m\u1ed9t ch\u00fat, \u0111\u1eb7c bi\u1ec7t l\u00e0 khi truy c\u1eadp l\u1ea7n \u0111\u1ea7u.<\/p>\n<p>T\u00f3m l\u1ea1i, DNS kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t ti\u1ec7n \u00edch m\u00e0 l\u00e0 m\u1ed9t th\u00e0nh ph\u1ea7n h\u1ea1 t\u1ea7ng thi\u1ebft y\u1ebfu. N\u00f3 \u0111\u1ea3m b\u1ea3o t\u00ednh th\u00e2n thi\u1ec7n, hi\u1ec7u qu\u1ea3 v\u00e0 ho\u1ea1t \u0111\u1ed9ng tr\u01a1n tru c\u1ee7a ph\u1ea7n l\u1edbn c\u00e1c ho\u1ea1t \u0111\u1ed9ng tr\u1ef1c tuy\u1ebfn m\u00e0 ch\u00fang ta th\u1ef1c hi\u1ec7n h\u00e0ng ng\u00e0y, t\u1eeb l\u01b0\u1edbt web, g\u1eedi email \u0111\u1ebfn s\u1eed d\u1ee5ng c\u00e1c \u1ee9ng d\u1ee5ng online.<\/p>\n<div style=\"background-color: #e6f2ff; border-radius: 10px; padding: 20px; margin: 20px 0; border: 1px solid #b3d9ff;\">\n<p>T\u1ea5t nhi\u00ean, \u0111\u1ec3 ng\u01b0\u1eddi d\u00f9ng c\u00f3 tr\u1ea3i nghi\u1ec7m t\u1ed1t nh\u1ea5t sau khi DNS \u0111\u00e3 ch\u1ec9 \u0111\u00fang \u0111\u01b0\u1eddng, website c\u1ee7a b\u1ea1n c\u1ea7n \u0111\u01b0\u1ee3c \u0111\u1eb7t tr\u00ean m\u1ed9t n\u1ec1n t\u1ea3ng v\u1eefng ch\u1eafc. D\u1ecbch v\u1ee5 <strong><a target=\"_blank\" rel=\"noopener noreferrer\" href=\"https:\/\/interdata.vn\/thue-hosting\/\">thu\u00ea Hosting<\/a><\/strong> uy t\u00edn t\u1ea1i InterData cung c\u1ea5p gi\u1ea3i ph\u00e1p ch\u1ea5t l\u01b0\u1ee3ng v\u1edbi ph\u1ea7n c\u1ee9ng th\u1ebf h\u1ec7 m\u1edbi chuy\u00ean d\u1ee5ng: chip <a href=\"https:\/\/interdata.vn\/blog\/cpu-amd-epyc\/\">AMD EPYC<\/a> Gen 3th, SSD NVMe U.2 t\u1ed1c \u0111\u1ed9 cao, <a href=\"https:\/\/interdata.vn\/blog\/bang-thong-la-gi\/\">b\u0103ng th\u00f4ng<\/a> l\u1edbn v\u00e0 dung l\u01b0\u1ee3ng t\u1ed1i \u01b0u. Tr\u1ea3i nghi\u1ec7m c\u1ea5u h\u00ecnh m\u1ea1nh m\u1ebd, \u1ed5n \u0111\u1ecbnh v\u01b0\u1ee3t tr\u1ed9i ch\u1ec9 t\u1eeb 1K\/ng\u00e0y.<\/p>\n<\/div>\n<h2><span class=\"ez-toc-section\" id=\"DNS-hoat-dong-nhu-the-nao\"><\/span>DNS ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Qu\u00e1 tr\u00ecnh <strong>DNS ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o<\/strong> \u0111\u1ec3 bi\u1ebfn m\u1ed9t t\u00ean mi\u1ec1n th\u00e0nh \u0111\u1ecba ch\u1ec9 IP di\u1ec5n ra r\u1ea5t nhanh ch\u00f3ng, th\u01b0\u1eddng ch\u1ec9 trong v\u00e0i mili gi\u00e2y. V\u1ec1 c\u01a1 b\u1ea3n, \u0111\u00f3 l\u00e0 m\u1ed9t chu\u1ed7i c\u00e1c b\u01b0\u1edbc <a href=\"https:\/\/interdata.vn\/blog\/query-la-gi\/\">truy v\u1ea5n<\/a> v\u00e0 ph\u1ea3n h\u1ed3i gi\u1eefa nhi\u1ec1u lo\u1ea1i m\u00e1y ch\u1ee7 DNS kh\u00e1c nhau. H\u00e3y c\u00f9ng xem quy tr\u00ecnh n\u00e0y di\u1ec5n ra qua c\u00e1c b\u01b0\u1edbc ch\u00ednh:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-02.jpg\" alt=\"Domain Name System (DNS) 02\" width=\"750\" height=\"331\" class=\"aligncenter size-full wp-image-27722\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-02.jpg 750w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-02-300x132.jpg 300w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Cac-buoc-chinh-trong-quy-trinh-phan-giai-DNS\"><\/span>C\u00e1c b\u01b0\u1edbc ch\u00ednh trong quy tr\u00ecnh ph\u00e2n gi\u1ea3i DNS<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li><strong>Ng\u01b0\u1eddi d\u00f9ng nh\u1eadp t\u00ean mi\u1ec1n:<\/strong> B\u1ea1n g\u00f5 <code><a href=\"https:\/\/interdata.vn\/blog\/world-wide-web\/\">www<\/a>.example.com<\/code> v\u00e0o thanh \u0111\u1ecba ch\u1ec9 c\u1ee7a <strong>tr\u00ecnh duy\u1ec7t web<\/strong> v\u00e0 nh\u1ea5n Enter. Tr\u00ecnh duy\u1ec7t s\u1ebd b\u1eaft \u0111\u1ea7u <strong>truy v\u1ea5n DNS<\/strong>.<\/li>\n<li><strong>Ki\u1ec3m tra <a href=\"https:\/\/interdata.vn\/blog\/cache-la-gi\/\">Cache<\/a> c\u1ee5c b\u1ed9:<\/strong> Tr\u00ecnh duy\u1ec7t v\u00e0 <a href=\"https:\/\/interdata.vn\/blog\/he-dieu-hanh\/\">h\u1ec7 \u0111i\u1ec1u h\u00e0nh<\/a> (Windows, macOS) s\u1ebd ki\u1ec3m tra b\u1ed9 nh\u1edb \u0111\u1ec7m (<strong>DNS Cache<\/strong>) c\u1ee7a ch\u00ednh n\u00f3 xem \u0111\u00e3 c\u00f3 \u0111\u1ecba ch\u1ec9 IP cho <code>www.example.com<\/code> t\u1eeb l\u1ea7n truy c\u1eadp tr\u01b0\u1edbc ch\u01b0a. N\u1ebfu c\u00f3, n\u00f3 s\u1ebd d\u00f9ng ngay IP n\u00e0y (qu\u00e1 tr\u00ecnh k\u1ebft th\u00fac \u1edf \u0111\u00e2y).<\/li>\n<li><strong>Truy v\u1ea5n DNS Resolver:<\/strong> N\u1ebfu kh\u00f4ng c\u00f3 trong cache, tr\u00ecnh duy\u1ec7t\/h\u1ec7 \u0111i\u1ec1u h\u00e0nh s\u1ebd g\u1eedi truy v\u1ea5n \u0111\u1ebfn <strong>DNS Resolver<\/strong> (c\u00f2n g\u1ecdi l\u00e0 Recursive Server). \u0110\u00e2y th\u01b0\u1eddng l\u00e0 <strong>m\u00e1y ch\u1ee7 DNS<\/strong> do Nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 Internet (ISP) c\u1ee7a b\u1ea1n cung c\u1ea5p, ho\u1eb7c l\u00e0 m\u1ed9t Public DNS nh\u01b0 Google DNS, <a href=\"https:\/\/interdata.vn\/blog\/cloudflare-la-gi\/\">Cloudflare<\/a> DNS m\u00e0 b\u1ea1n \u0111\u00e3 c\u1ea5u h\u00ecnh.<\/li>\n<li><strong>Resolver truy v\u1ea5n Root Server:<\/strong> DNS Resolver s\u1ebd h\u1ecfi m\u1ed9t trong c\u00e1c <strong>Root <a href=\"https:\/\/interdata.vn\/blog\/name-server-la-gi\/\">Name Server<\/a><\/strong> (m\u00e1y ch\u1ee7 t\u00ean mi\u1ec1n g\u1ed1c) tr\u00ean th\u1ebf gi\u1edbi: &#8220;Ai qu\u1ea3n l\u00fd t\u00ean mi\u1ec1n <code><a href=\"https:\/\/interdata.vn\/blog\/ten-mien-com-la-gi\/\">.com<\/a><\/code>?&#8221;. Root Server kh\u00f4ng bi\u1ebft IP c\u1ee7a <code>www.example.com<\/code> nh\u01b0ng n\u00f3 bi\u1ebft ai qu\u1ea3n l\u00fd \u0111u\u00f4i <code>.com<\/code>.<\/li>\n<li><strong>Root Server tr\u1ea3 v\u1ec1 <a href=\"https:\/\/interdata.vn\/blog\/top-level-domain\/\">TLD<\/a> Server:<\/strong> Root Server tr\u1ea3 l\u1eddi Resolver \u0111\u1ecba ch\u1ec9 c\u1ee7a <strong>TLD Name Server<\/strong> (m\u00e1y ch\u1ee7 t\u00ean mi\u1ec1n c\u1ea5p cao nh\u1ea5t) ch\u1ecbu tr\u00e1ch nhi\u1ec7m cho \u0111u\u00f4i <code>.com<\/code>.<\/li>\n<li><strong>Resolver truy v\u1ea5n TLD Server:<\/strong> Resolver ti\u1ebfp t\u1ee5c h\u1ecfi TLD Server: &#8220;Ai qu\u1ea3n l\u00fd t\u00ean mi\u1ec1n <code>example.com<\/code>?&#8221;. TLD Server c\u0169ng kh\u00f4ng bi\u1ebft IP cu\u1ed1i c\u00f9ng, nh\u01b0ng n\u00f3 bi\u1ebft \u0111\u1ecba ch\u1ec9 c\u1ee7a m\u00e1y ch\u1ee7 DNS c\u00f3 th\u1ea9m quy\u1ec1n cho t\u00ean mi\u1ec1n \u0111\u00f3.<\/li>\n<li><strong>TLD Server tr\u1ea3 v\u1ec1 Authoritative Server:<\/strong> TLD Server tr\u1ea3 l\u1eddi Resolver \u0111\u1ecba ch\u1ec9 c\u1ee7a <strong>Authoritative Name Server<\/strong> (m\u00e1y ch\u1ee7 t\u00ean mi\u1ec1n c\u00f3 th\u1ea9m quy\u1ec1n) qu\u1ea3n l\u00fd <code>example.com<\/code>.<\/li>\n<li><strong>Resolver truy v\u1ea5n Authoritative Server:<\/strong> Resolver h\u1ecfi Authoritative Server: &#8220;\u0110\u1ecba ch\u1ec9 IP c\u1ee7a <code>www.example.com<\/code> l\u00e0 g\u00ec?&#8221;. Authoritative Server ch\u1ee9a th\u00f4ng tin <strong>b\u1ea3n ghi DNS<\/strong> cho t\u00ean mi\u1ec1n n\u00e0y v\u00e0 s\u1ebd tr\u1ea3 l\u1eddi b\u1eb1ng \u0111\u1ecba ch\u1ec9 IP ch\u00ednh x\u00e1c.<\/li>\n<li><strong>Resolver tr\u1ea3 IP v\u1ec1 Tr\u00ecnh duy\u1ec7t:<\/strong> DNS Resolver nh\u1eadn \u0111\u01b0\u1ee3c \u0111\u1ecba ch\u1ec9 IP v\u00e0 l\u01b0u v\u00e0o cache c\u1ee7a n\u00f3 (\u0111\u1ec3 d\u00f9ng cho c\u00e1c truy v\u1ea5n sau), sau \u0111\u00f3 g\u1eedi \u0111\u1ecba ch\u1ec9 IP n\u00e0y v\u1ec1 cho tr\u00ecnh duy\u1ec7t web c\u1ee7a b\u1ea1n.<\/li>\n<li><strong>Tr\u00ecnh duy\u1ec7t k\u1ebft n\u1ed1i \u0111\u1ebfn Website:<\/strong> Tr\u00ecnh duy\u1ec7t cu\u1ed1i c\u00f9ng \u0111\u00e3 c\u00f3 \u0111\u1ecba ch\u1ec9 IP c\u1ea7n thi\u1ebft. N\u00f3 s\u1eed d\u1ee5ng IP n\u00e0y \u0111\u1ec3 thi\u1ebft l\u1eadp k\u1ebft n\u1ed1i tr\u1ef1c ti\u1ebfp \u0111\u1ebfn <a href=\"https:\/\/interdata.vn\/blog\/web-server\/\">m\u00e1y ch\u1ee7 web<\/a> (web server) c\u1ee7a <code>www.example.com<\/code> v\u00e0 t\u1ea3i n\u1ed9i dung trang web v\u1ec1 hi\u1ec3n th\u1ecb cho b\u1ea1n.<\/li>\n<\/ol>\n<p>To\u00e0n b\u1ed9 qu\u00e1 tr\u00ecnh ph\u1ee9c t\u1ea1p n\u00e0y th\u01b0\u1eddng di\u1ec5n ra ch\u1ec9 trong t\u00edch t\u1eafc, \u0111\u1ea3m b\u1ea3o tr\u1ea3i nghi\u1ec7m duy\u1ec7t web m\u01b0\u1ee3t m\u00e0.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Vi-du-minh-hoa-thuc-te\"><\/span>V\u00ed d\u1ee5 minh h\u1ecda th\u1ef1c t\u1ebf<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>H\u00e3y xem v\u00ed d\u1ee5 khi b\u1ea1n mu\u1ed1n truy c\u1eadp trang b\u00e1o <code>vnexpress.net<\/code>:<\/p>\n<ol>\n<li>B\u1ea1n g\u00f5 <code>vnexpress.net<\/code> v\u00e0o tr\u00ecnh duy\u1ec7t.<\/li>\n<li>Tr\u00ecnh duy\u1ec7t\/OS ki\u1ec3m tra cache, gi\u1ea3 s\u1eed kh\u00f4ng c\u00f3 IP cho <code>vnexpress.net<\/code>.<\/li>\n<li>Truy v\u1ea5n \u0111\u01b0\u1ee3c g\u1eedi \u0111\u1ebfn DNS Resolver (v\u00ed d\u1ee5: DNS c\u1ee7a VNPT ho\u1eb7c DNS 8.8.8.8 c\u1ee7a Google).<\/li>\n<li>Resolver h\u1ecfi Root Server v\u1ec1 \u0111u\u00f4i <code>.net<\/code>.<\/li>\n<li>Root Server ch\u1ec9 \u0111\u1ebfn TLD Server qu\u1ea3n l\u00fd <code>.net<\/code>.<\/li>\n<li>Resolver h\u1ecfi TLD Server v\u1ec1 <code>vnexpress.net<\/code>.<\/li>\n<li>TLD Server ch\u1ec9 \u0111\u1ebfn Authoritative Server c\u1ee7a <code>vnexpress.net<\/code> (do FPT Online qu\u1ea3n l\u00fd).<\/li>\n<li>Resolver h\u1ecfi Authoritative Server \u0111\u1ecba ch\u1ec9 IP c\u1ee7a <code>vnexpress.net<\/code>.<\/li>\n<li>Authoritative Server tr\u1ea3 v\u1ec1 \u0111\u1ecba ch\u1ec9 IP (v\u00ed d\u1ee5: <code>118.69.161.xxx<\/code>).<\/li>\n<li>Resolver tr\u1ea3 IP n\u00e0y v\u1ec1 tr\u00ecnh duy\u1ec7t c\u1ee7a b\u1ea1n.<\/li>\n<li>Tr\u00ecnh duy\u1ec7t d\u00f9ng IP <code>118.69.161.xxx<\/code> \u0111\u1ec3 k\u1ebft n\u1ed1i v\u00e0 t\u1ea3i trang VnExpress.<\/li>\n<\/ol>\n<h2><span class=\"ez-toc-section\" id=\"Cac-thanh-phan-chinh-trong-he-thong-DNS\"><\/span>C\u00e1c th\u00e0nh ph\u1ea7n ch\u00ednh trong h\u1ec7 th\u1ed1ng DNS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u1ec3 hi\u1ec3u r\u00f5 h\u01a1n c\u00e1ch DNS ho\u1ea1t \u0111\u1ed9ng, ch\u00fang ta c\u1ea7n bi\u1ebft v\u1ec1 c\u00e1c &#8220;nh\u00e2n v\u1eadt&#8221; ch\u00ednh tham gia v\u00e0o h\u1ec7 th\u1ed1ng n\u00e0y:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-03.jpg\" alt=\"Domain Name System (DNS) 03\" width=\"750\" height=\"375\" class=\"aligncenter size-full wp-image-27723\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-03.jpg 750w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-03-300x150.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-03-360x180.jpg 360w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"DNS-Resolver-Trinh-phan-giai-DNS-May-chu-DNS-de-quy\"><\/span>DNS Resolver (Tr\u00ecnh ph\u00e2n gi\u1ea3i DNS \/ M\u00e1y ch\u1ee7 DNS \u0111\u1ec7 quy)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u00e2y l\u00e0 <strong>m\u00e1y ch\u1ee7 DNS<\/strong> \u0111\u1ea7u ti\u00ean m\u00e0 m\u00e1y t\u00ednh c\u1ee7a b\u1ea1n li\u00ean h\u1ec7 khi c\u1ea7n <strong>ph\u00e2n gi\u1ea3i t\u00ean mi\u1ec1n<\/strong>. N\u00f3 \u0111\u00f3ng vai tr\u00f2 nh\u01b0 m\u1ed9t &#8220;ng\u01b0\u1eddi trung gian&#8221; c\u1ea7n m\u1eabn, thay m\u1eb7t b\u1ea1n \u0111i h\u1ecfi c\u00e1c m\u00e1y ch\u1ee7 kh\u00e1c (Root, TLD, Authoritative) \u0111\u1ec3 t\u00ecm ra \u0111\u1ecba ch\u1ec9 IP cu\u1ed1i c\u00f9ng. <strong>DNS Resolver<\/strong> th\u01b0\u1eddng \u0111\u01b0\u1ee3c cung c\u1ea5p b\u1edfi <strong>ISP<\/strong> c\u1ee7a b\u1ea1n ho\u1eb7c c\u00e1c d\u1ecbch v\u1ee5 <strong>Public DNS<\/strong> (DNS c\u00f4ng c\u1ed9ng).<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Root-Name-Server-May-chu-ten-mien-goc\"><\/span>Root Name Server (M\u00e1y ch\u1ee7 t\u00ean mi\u1ec1n g\u1ed1c)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u00e2y l\u00e0 c\u1ea5p cao nh\u1ea5t trong h\u1ec7 th\u1ed1ng ph\u00e2n c\u1ea5p DNS. C\u00f3 13 \u0111\u1ecba ch\u1ec9 IP m\u00e1y ch\u1ee7 g\u1ed1c logic tr\u00ean to\u00e0n c\u1ea7u (nh\u01b0ng \u0111\u01b0\u1ee3c nh\u00e2n b\u1ea3n ra h\u00e0ng tr\u0103m v\u1ecb tr\u00ed v\u1eadt l\u00fd). Ch\u00fang kh\u00f4ng ch\u1ee9a th\u00f4ng tin v\u1ec1 t\u1eebng t\u00ean mi\u1ec1n c\u1ee5 th\u1ec3, m\u00e0 ch\u1ec9 gi\u1eef th\u00f4ng tin v\u1ec1 \u0111\u1ecba ch\u1ec9 c\u1ee7a c\u00e1c TLD Name Server. Ch\u00fang gi\u1ed1ng nh\u01b0 ng\u01b0\u1eddi g\u00e1c c\u1ed5ng ch\u00ednh c\u1ee7a Internet.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"TLD-Name-Server-May-chu-ten-mien-cap-cao-nhat\"><\/span>TLD Name Server (M\u00e1y ch\u1ee7 t\u00ean mi\u1ec1n c\u1ea5p cao nh\u1ea5t)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>C\u00e1c m\u00e1y ch\u1ee7 n\u00e0y qu\u1ea3n l\u00fd th\u00f4ng tin cho c\u00e1c t\u00ean mi\u1ec1n c\u1ea5p cao nh\u1ea5t (Top-Level Domains &#8211; TLDs), v\u00ed d\u1ee5 nh\u01b0 <code>.com<\/code>, <code>.org<\/code>, <code>.net<\/code>, <code>.gov<\/code>, hay c\u00e1c TLD qu\u1ed1c gia nh\u01b0 <code><a href=\"https:\/\/interdata.vn\/blog\/ten-mien-vn-la-gi\/\">.vn<\/a><\/code>, <code>.uk<\/code>, <code>.jp<\/code>. Khi Resolver h\u1ecfi v\u1ec1 <code>example.com<\/code>, Root Server s\u1ebd ch\u1ec9 \u0111\u1ebfn TLD Server qu\u1ea3n l\u00fd <code>.com<\/code>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Authoritative-Name-Server-May-chu-ten-mien-co-tham-quyen\"><\/span>Authoritative Name Server (M\u00e1y ch\u1ee7 t\u00ean mi\u1ec1n c\u00f3 th\u1ea9m quy\u1ec1n)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u00e2y l\u00e0 \u0111\u00edch \u0111\u1ebfn cu\u1ed1i c\u00f9ng trong h\u00e0nh tr\u00ecnh truy v\u1ea5n DNS. M\u00e1y ch\u1ee7 n\u00e0y ch\u1ee9a th\u00f4ng tin <strong>b\u1ea3n ghi DNS<\/strong> (DNS Records) ch\u00ednh th\u1ee9c v\u00e0 \u0111\u1ea7y \u0111\u1ee7 cho m\u1ed9t t\u00ean mi\u1ec1n c\u1ee5 th\u1ec3. Khi Resolver h\u1ecfi Authoritative Server v\u1ec1 <code>www.example.com<\/code>, n\u00f3 s\u1ebd nh\u1eadn \u0111\u01b0\u1ee3c c\u00e2u tr\u1ea3 l\u1eddi cu\u1ed1i c\u00f9ng (\u0111\u1ecba ch\u1ec9 IP ho\u1eb7c th\u00f4ng tin kh\u00e1c). M\u00e1y ch\u1ee7 n\u00e0y th\u01b0\u1eddng do c\u00f4ng ty \u0111\u0103ng k\u00fd t\u00ean mi\u1ec1n ho\u1eb7c nh\u00e0 cung c\u1ea5p hosting qu\u1ea3n l\u00fd.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Ban-ghi-DNS-DNS-Records\"><\/span>B\u1ea3n ghi DNS (DNS Records)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u00e2y kh\u00f4ng ph\u1ea3i l\u00e0 m\u00e1y ch\u1ee7, m\u00e0 l\u00e0 c\u00e1c \u0111\u01a1n v\u1ecb th\u00f4ng tin \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef tr\u00ean Authoritative Name Server. M\u1ed7i b\u1ea3n ghi ch\u1ee9a m\u1ed9t ch\u1ec9 d\u1eabn c\u1ee5 th\u1ec3, v\u00ed d\u1ee5: &#8220;t\u00ean mi\u1ec1n <code>A<\/code> t\u01b0\u01a1ng \u1ee9ng v\u1edbi \u0111\u1ecba ch\u1ec9 IP <code>X<\/code>&#8220;, ho\u1eb7c &#8220;email cho t\u00ean mi\u1ec1n <code>Y<\/code> n\u00ean \u0111\u01b0\u1ee3c g\u1eedi \u0111\u1ebfn m\u00e1y ch\u1ee7 <code>Z<\/code>&#8220;. C\u00f3 nhi\u1ec1u lo\u1ea1i b\u1ea3n ghi DNS kh\u00e1c nhau cho c\u00e1c m\u1ee5c \u0111\u00edch kh\u00e1c nhau.<\/p>\n<p>S\u1ef1 ph\u1ed1i h\u1ee3p nh\u1ecbp nh\u00e0ng gi\u1eefa c\u00e1c th\u00e0nh ph\u1ea7n n\u00e0y \u0111\u1ea3m b\u1ea3o h\u1ec7 th\u1ed1ng DNS ho\u1ea1t \u0111\u1ed9ng hi\u1ec7u qu\u1ea3, gi\u00fap k\u1ebft n\u1ed1i h\u00e0ng t\u1ef7 thi\u1ebft b\u1ecb tr\u00ean to\u00e0n c\u1ea7u.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cac-loai-ban-ghi-DNS-DNS-Records-pho-bien-nhat\"><\/span>C\u00e1c lo\u1ea1i b\u1ea3n ghi DNS (DNS Records) ph\u1ed5 bi\u1ebfn nh\u1ea5t<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>B\u1ea3n ghi DNS (DNS Records)<\/strong> l\u00e0 nh\u1eefng ch\u1ec9 d\u1eabn c\u1ed1t l\u00f5i \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef tr\u00ean Authoritative Name Server, quy \u0111\u1ecbnh c\u00e1ch x\u1eed l\u00fd c\u00e1c y\u00eau c\u1ea7u li\u00ean quan \u0111\u1ebfn m\u1ed9t t\u00ean mi\u1ec1n. N\u1ebfu b\u1ea1n s\u1edf h\u1eefu m\u1ed9t website ho\u1eb7c qu\u1ea3n l\u00fd t\u00ean mi\u1ec1n, vi\u1ec7c hi\u1ec3u c\u00e1c lo\u1ea1i b\u1ea3n ghi DNS c\u01a1 b\u1ea3n l\u00e0 r\u1ea5t quan tr\u1ecdng \u0111\u1ec3 <strong>c\u1ea5u h\u00ecnh DNS<\/strong> ch\u00ednh x\u00e1c. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 c\u00e1c lo\u1ea1i ph\u1ed5 bi\u1ebfn nh\u1ea5t:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-04.jpg\" alt=\"Domain Name System (DNS) 04\" width=\"750\" height=\"567\" class=\"aligncenter size-full wp-image-27724\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-04.jpg 750w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-04-300x227.jpg 300w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Ban-ghi-A-Address-Mapping\"><\/span>B\u1ea3n ghi A (Address Mapping)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>M\u1ee5c \u0111\u00edch:<\/strong> \u00c1nh x\u1ea1 (tr\u1ecf) m\u1ed9t t\u00ean mi\u1ec1n ho\u1eb7c t\u00ean mi\u1ec1n ph\u1ee5 (<a href=\"https:\/\/interdata.vn\/blog\/subdomain-la-gi\/\">subdomain<\/a>) t\u1edbi m\u1ed9t <strong>\u0111\u1ecba ch\u1ec9 <a href=\"https:\/\/interdata.vn\/blog\/ipv4-la-gi\/\">IPv4<\/a><\/strong>. \u0110\u00e2y l\u00e0 b\u1ea3n ghi c\u01a1 b\u1ea3n v\u00e0 quan tr\u1ecdng nh\u1ea5t \u0111\u1ec3 website c\u00f3 th\u1ec3 ho\u1ea1t \u0111\u1ed9ng.<\/li>\n<li><strong>V\u00ed d\u1ee5:<\/strong> <code>example.com A 192.0.2.1<\/code> (Ngh\u0129a l\u00e0 <code>example.com<\/code> tr\u1ecf \u0111\u1ebfn IP <code>192.0.2.1<\/code>)<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Ban-ghi-AAAA-IPv6-Address-Mapping\"><\/span>B\u1ea3n ghi AAAA (IPv6 Address Mapping)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>M\u1ee5c \u0111\u00edch:<\/strong> T\u01b0\u01a1ng t\u1ef1 <a href=\"https:\/\/interdata.vn\/blog\/ban-ghi-a-la-gi\/\">b\u1ea3n ghi A<\/a>, nh\u01b0ng d\u00f9ng \u0111\u1ec3 \u00e1nh x\u1ea1 t\u00ean mi\u1ec1n t\u1edbi m\u1ed9t <strong>\u0111\u1ecba ch\u1ec9 <a href=\"https:\/\/interdata.vn\/blog\/ipv6-la-gi\/\">IPv6<\/a><\/strong>. Khi IPv6 ng\u00e0y c\u00e0ng ph\u1ed5 bi\u1ebfn, b\u1ea3n ghi AAAA tr\u1edf n\u00ean quan tr\u1ecdng h\u01a1n.<\/li>\n<li><strong>V\u00ed d\u1ee5:<\/strong> <code>example.com AAAA 2001:db8::1<\/code><\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Ban-ghi-CNAME-Canonical-Name\"><\/span>B\u1ea3n ghi CNAME (Canonical Name)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>M\u1ee5c \u0111\u00edch:<\/strong> T\u1ea1o m\u1ed9t t\u00ean b\u00ed danh (alias), tr\u1ecf m\u1ed9t t\u00ean mi\u1ec1n ho\u1eb7c t\u00ean mi\u1ec1n ph\u1ee5 n\u00e0y sang m\u1ed9t t\u00ean mi\u1ec1n <i>kh\u00e1c<\/i>. N\u00f3 h\u1eefu \u00edch khi b\u1ea1n mu\u1ed1n nhi\u1ec1u t\u00ean mi\u1ec1n c\u00f9ng tr\u1ecf v\u1ec1 m\u1ed9t n\u01a1i ho\u1eb7c khi d\u00f9ng d\u1ecbch v\u1ee5 b\u00ean th\u1ee9 ba (nh\u01b0 <a href=\"https:\/\/interdata.vn\/blog\/cdn-la-gi\/\">CDN<\/a>).<\/li>\n<li><strong>V\u00ed d\u1ee5:<\/strong> <code>www.example.com CNAME example.com<\/code> (Ngh\u0129a l\u00e0 <code>www.example.com<\/code> l\u00e0 b\u00ed danh c\u1ee7a <code>example.com<\/code>, c\u00f9ng tr\u1ecf v\u1ec1 n\u01a1i <code>example.com<\/code> \u0111ang tr\u1ecf t\u1edbi).<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Ban-ghi-MX-Mail-Exchanger\"><\/span>B\u1ea3n ghi MX (Mail Exchanger)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>M\u1ee5c \u0111\u00edch:<\/strong> Ch\u1ec9 \u0111\u1ecbnh c\u00e1c m\u00e1y ch\u1ee7 email (mail server) ch\u1ecbu tr\u00e1ch nhi\u1ec7m nh\u1eadn email cho t\u00ean mi\u1ec1n c\u1ee7a b\u1ea1n. N\u1ebfu kh\u00f4ng c\u00f3 b\u1ea3n ghi MX, b\u1ea1n s\u1ebd kh\u00f4ng nh\u1eadn \u0111\u01b0\u1ee3c email.<\/li>\n<li><strong>V\u00ed d\u1ee5:<\/strong> <code>example.com MX 10 mail.example.com<\/code> (S\u1ed1 10 l\u00e0 m\u1ee9c \u0111\u1ed9 \u01b0u ti\u00ean, s\u1ed1 nh\u1ecf h\u01a1n \u0111\u01b0\u1ee3c \u01b0u ti\u00ean cao h\u01a1n).<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Ban-ghi-TXT-Text-Record\"><\/span>B\u1ea3n ghi TXT (Text Record)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>M\u1ee5c \u0111\u00edch:<\/strong> Cho ph\u00e9p qu\u1ea3n tr\u1ecb vi\u00ean t\u00ean mi\u1ec1n l\u01b0u tr\u1eef th\u00f4ng tin d\u1ea1ng v\u0103n b\u1ea3n (text) t\u00f9y \u00fd. N\u00f3 th\u01b0\u1eddng \u0111\u01b0\u1ee3c d\u00f9ng cho c\u00e1c m\u1ee5c \u0111\u00edch x\u00e1c th\u1ef1c t\u00ean mi\u1ec1n (v\u1edbi Google Search Console, Microsoft 365), c\u1ea5u h\u00ecnh ch\u00ednh s\u00e1ch b\u1ea3o m\u1eadt email nh\u01b0 SPF (Sender Policy <a href=\"https:\/\/interdata.vn\/blog\/framework-la-gi\/\">Framework<\/a>), DKIM (DomainKeys Identified Mail) \u0111\u1ec3 ch\u1ed1ng spam v\u00e0 gi\u1ea3 m\u1ea1o email.<\/li>\n<li><strong>V\u00ed d\u1ee5 (SPF):<\/strong> <code>example.com TXT \"v=spf1 include:_spf.google.com ~all\"<\/code><\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Ban-ghi-NS-Name-Server\"><\/span>B\u1ea3n ghi NS (Name Server)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>M\u1ee5c \u0111\u00edch:<\/strong> Ch\u1ec9 \u0111\u1ecbnh c\u00e1c <strong>Authoritative Name Server<\/strong> ch\u1ecbu tr\u00e1ch nhi\u1ec7m cho t\u00ean mi\u1ec1n n\u00e0y. Khi b\u1ea1n mua t\u00ean mi\u1ec1n v\u00e0 s\u1eed d\u1ee5ng hosting \u1edf n\u01a1i kh\u00e1c, b\u1ea1n th\u01b0\u1eddng c\u1ea7n c\u1eadp nh\u1eadt b\u1ea3n ghi NS t\u1ea1i nh\u00e0 \u0111\u0103ng k\u00fd t\u00ean mi\u1ec1n \u0111\u1ec3 tr\u1ecf v\u1ec1 Name Server c\u1ee7a nh\u00e0 cung c\u1ea5p hosting.<\/li>\n<li><strong>V\u00ed d\u1ee5:<\/strong> <code>example.com NS ns1.hostingprovider.com<\/code><\/li>\n<\/ul>\n<p>Vi\u1ec7c hi\u1ec3u v\u00e0 c\u1ea5u h\u00ecnh \u0111\u00fang c\u00e1c b\u1ea3n ghi n\u00e0y l\u00e0 ch\u00eca kh\u00f3a \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o website, email v\u00e0 c\u00e1c d\u1ecbch v\u1ee5 kh\u00e1c li\u00ean quan \u0111\u1ebfn t\u00ean mi\u1ec1n c\u1ee7a b\u1ea1n ho\u1ea1t \u0111\u1ed9ng \u1ed5n \u0111\u1ecbnh.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cac-loai-May-chu-DNS-DNS-Server\"><\/span>C\u00e1c lo\u1ea1i M\u00e1y ch\u1ee7 DNS (DNS Server)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Khi n\u00f3i v\u1ec1 <strong>M\u00e1y ch\u1ee7 DNS (DNS Server)<\/strong>, ng\u01b0\u1eddi d\u00f9ng cu\u1ed1i th\u01b0\u1eddng t\u01b0\u01a1ng t\u00e1c ho\u1eb7c nghe n\u00f3i v\u1ec1 m\u1ed9t s\u1ed1 lo\u1ea1i ch\u00ednh. Vi\u1ec7c ph\u00e2n bi\u1ec7t ch\u00fang gi\u00fap b\u1ea1n hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 c\u00e1ch k\u1ebft n\u1ed1i Internet c\u1ee7a m\u00ecnh ho\u1ea1t \u0111\u1ed9ng v\u00e0 c\u00e1c l\u1ef1a ch\u1ecdn \u0111\u1ec3 t\u1ed1i \u01b0u n\u00f3:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-05.jpg\" alt=\"Domain Name System (DNS) 05\" width=\"750\" height=\"326\" class=\"aligncenter size-full wp-image-27725\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-05.jpg 750w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-05-300x130.jpg 300w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"DNS-Server-cua-Nha-cung-cap-Internet-ISP-DNS\"><\/span>DNS Server c\u1ee7a Nh\u00e0 cung c\u1ea5p Internet (ISP DNS)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u00e2y l\u00e0 c\u00e1c <strong>m\u00e1y ch\u1ee7 DNS<\/strong> \u0111\u01b0\u1ee3c t\u1ef1 \u0111\u1ed9ng g\u00e1n cho b\u1ea1n khi b\u1ea1n k\u1ebft n\u1ed1i m\u1ea1ng th\u00f4ng qua Nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 Internet (ISP) nh\u01b0 VNPT, FPT, Viettel&#8230; Ch\u00fang d\u1ec5 s\u1eed d\u1ee5ng v\u00ec b\u1ea1n kh\u00f4ng c\u1ea7n c\u1ea5u h\u00ecnh g\u00ec c\u1ea3. Tuy nhi\u00ean, t\u1ed1c \u0111\u1ed9 v\u00e0 \u0111\u1ed9 \u1ed5n \u0111\u1ecbnh c\u1ee7a ISP DNS c\u00f3 th\u1ec3 kh\u00f4ng ph\u1ea3i l\u00fac n\u00e0o c\u0169ng t\u1ed1t nh\u1ea5t, v\u00e0 \u0111\u00f4i khi ISP c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng DNS \u0111\u1ec3 ch\u1eb7n truy c\u1eadp m\u1ed9t s\u1ed1 trang web ho\u1eb7c ghi l\u1ea1i l\u1ecbch s\u1eed duy\u1ec7t web c\u1ee7a ng\u01b0\u1eddi d\u00f9ng.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Public-DNS-Server-May-chu-DNS-cong-cong\"><\/span>Public DNS Server (M\u00e1y ch\u1ee7 DNS c\u00f4ng c\u1ed9ng)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u00e2y l\u00e0 c\u00e1c m\u00e1y ch\u1ee7 DNS \u0111\u01b0\u1ee3c cung c\u1ea5p mi\u1ec5n ph\u00ed cho c\u1ed9ng \u0111\u1ed3ng b\u1edfi c\u00e1c t\u1ed5 ch\u1ee9c l\u1edbn, v\u1edbi m\u1ee5c ti\u00eau c\u1ea3i thi\u1ec7n t\u1ed1c \u0111\u1ed9, \u0111\u1ed9 tin c\u1eady v\u00e0 b\u1ea3o m\u1eadt khi duy\u1ec7t web. M\u1ed9t s\u1ed1 <strong>Public DNS<\/strong> ph\u1ed5 bi\u1ebfn nh\u1ea5t bao g\u1ed3m:<\/p>\n<ul>\n<li><strong>Google Public DNS:<\/strong> \u0110\u1ecba ch\u1ec9 <code>8.8.8.8<\/code> v\u00e0 <code>8.8.4.4<\/code>. N\u1ed5i ti\u1ebfng v\u1ec1 t\u1ed1c \u0111\u1ed9 v\u00e0 \u0111\u1ed9 \u1ed5n \u0111\u1ecbnh.<\/li>\n<li><strong>Cloudflare DNS:<\/strong> \u0110\u1ecba ch\u1ec9 <code>1.1.1.1<\/code> v\u00e0 <code>1.0.0.1<\/code>. T\u1eadp trung m\u1ea1nh v\u00e0o quy\u1ec1n ri\u00eang t\u01b0 v\u00e0 t\u1ed1c \u0111\u1ed9, h\u1ed7 tr\u1ee3 c\u00e1c chu\u1ea9n b\u1ea3o m\u1eadt m\u1edbi nh\u01b0 DNS over HTTPS (DoH), DNS over TLS (DoT).<\/li>\n<li><strong>OpenDNS:<\/strong> \u0110\u1ecba ch\u1ec9 <code>208.67.222.222<\/code> v\u00e0 <code>208.67.220.220<\/code>. Cung c\u1ea5p c\u00e1c t\u00ednh n\u0103ng l\u1ecdc n\u1ed9i dung (v\u00ed d\u1ee5: ch\u1eb7n web \u0111\u1ed9c h\u1ea1i, web ng\u01b0\u1eddi l\u1edbn) h\u1eefu \u00edch cho gia \u0111\u00ecnh v\u00e0 doanh nghi\u1ec7p.<\/li>\n<\/ul>\n<p>S\u1eed d\u1ee5ng Public DNS th\u01b0\u1eddng mang l\u1ea1i tr\u1ea3i nghi\u1ec7m duy\u1ec7t web nhanh h\u01a1n v\u00e0 an to\u00e0n h\u01a1n so v\u1edbi ISP DNS m\u1eb7c \u0111\u1ecbnh.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Private-DNS-Server-May-chu-DNS-rieng-tu\"><\/span>Private DNS Server (M\u00e1y ch\u1ee7 DNS ri\u00eang t\u01b0)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Lo\u1ea1i n\u00e0y \u00edt ph\u1ed5 bi\u1ebfn h\u01a1n v\u1edbi ng\u01b0\u1eddi d\u00f9ng c\u00e1 nh\u00e2n. \u0110\u00e2y l\u00e0 c\u00e1c m\u00e1y ch\u1ee7 DNS \u0111\u01b0\u1ee3c thi\u1ebft l\u1eadp v\u00e0 qu\u1ea3n l\u00fd b\u1edfi m\u1ed9t t\u1ed5 ch\u1ee9c ho\u1eb7c c\u00e1 nh\u00e2n cho m\u1ee5c \u0111\u00edch s\u1eed d\u1ee5ng n\u1ed9i b\u1ed9. V\u00ed d\u1ee5, m\u1ed9t c\u00f4ng ty l\u1edbn c\u00f3 th\u1ec3 c\u00f3 Private DNS Server \u0111\u1ec3 qu\u1ea3n l\u00fd t\u00ean c\u00e1c m\u00e1y ch\u1ee7, m\u00e1y in trong m\u1ea1ng n\u1ed9i b\u1ed9 c\u1ee7a h\u1ecd.<\/p>\n<p>Hi\u1ec3u v\u1ec1 c\u00e1c lo\u1ea1i DNS Server n\u00e0y gi\u00fap b\u1ea1n c\u00f3 th\u1ec3 \u0111\u01b0a ra l\u1ef1a ch\u1ecdn ph\u00f9 h\u1ee3p n\u1ebfu mu\u1ed1n <strong>thay \u0111\u1ed5i DNS<\/strong> m\u1eb7c \u0111\u1ecbnh \u0111\u1ec3 t\u1ed1i \u01b0u h\u00f3a k\u1ebft n\u1ed1i Internet c\u1ee7a m\u00ecnh.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Huong-dan-Cach-thay-doi-DNS-Server-Doi-DNS\"><\/span>H\u01b0\u1edbng d\u1eabn C\u00e1ch thay \u0111\u1ed5i DNS Server (\u0110\u1ed5i DNS)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Vi\u1ec7c <strong>thay \u0111\u1ed5i DNS<\/strong> server m\u1eb7c \u0111\u1ecbnh c\u1ee7a ISP sang m\u1ed9t Public DNS nh\u01b0 <strong>DNS Google<\/strong> (<code>8.8.8.8<\/code>) ho\u1eb7c <strong>DNS Cloudflare<\/strong> (<code>1.1.1.1<\/code>) l\u00e0 m\u1ed9t th\u1ee7 thu\u1eadt \u0111\u01a1n gi\u1ea3n nh\u01b0ng c\u00f3 th\u1ec3 mang l\u1ea1i nhi\u1ec1u l\u1ee3i \u00edch: c\u1ea3i thi\u1ec7n <strong>t\u1ed1c \u0111\u1ed9 truy c\u1eadp<\/strong> web, t\u0103ng c\u01b0\u1eddng <strong>b\u1ea3o m\u1eadt<\/strong> (m\u1ed9t s\u1ed1 Public DNS ch\u1eb7n c\u00e1c trang l\u1eeba \u0111\u1ea3o, \u0111\u1ed9c h\u1ea1i), v\u00e0 \u0111\u00f4i khi gi\u00fap <strong>truy c\u1eadp c\u00e1c website b\u1ecb ch\u1eb7n<\/strong> b\u1eb1ng ph\u01b0\u01a1ng ph\u00e1p ch\u1eb7n DNS.<\/p>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 h\u01b0\u1edbng d\u1eabn <strong>c\u00e1ch \u0111\u1ed5i DNS<\/strong> c\u01a1 b\u1ea3n tr\u00ean c\u00e1c h\u1ec7 \u0111i\u1ec1u h\u00e0nh ph\u1ed5 bi\u1ebfn:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-06.jpg\" alt=\"Domain Name System (DNS) 06\" width=\"750\" height=\"422\" class=\"aligncenter size-full wp-image-27726\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-06.jpg 750w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2024\/09\/Domain-Name-System-DNS-06-300x169.jpg 300w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Thay-doi-DNS-tren-may-tinh-Windows-1011\"><\/span>Thay \u0111\u1ed5i DNS tr\u00ean m\u00e1y t\u00ednh Windows (10\/11)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li>Nh\u1ea5n chu\u1ed9t ph\u1ea3i v\u00e0o n\u00fat Start, ch\u1ecdn &#8220;Network Connections&#8221; ho\u1eb7c t\u00ecm &#8220;View network connections&#8221; trong Control Panel.<\/li>\n<li>Chu\u1ed9t ph\u1ea3i v\u00e0o k\u1ebft n\u1ed1i m\u1ea1ng \u0111ang s\u1eed d\u1ee5ng (Wi-Fi ho\u1eb7c Ethernet), ch\u1ecdn &#8220;Properties&#8221;.<\/li>\n<li>Ch\u1ecdn &#8220;Internet Protocol Version 4 (TCP\/IPv4)&#8221;, nh\u1ea5n n\u00fat &#8220;Properties&#8221;.<\/li>\n<li>Ch\u1ecdn m\u1ee5c &#8220;Use the following DNS server addresses:&#8221;.<\/li>\n<li>Nh\u1eadp \u0111\u1ecba ch\u1ec9 DNS b\u1ea1n mu\u1ed1n d\u00f9ng. V\u00ed d\u1ee5, v\u1edbi Google DNS:\n<ul>\n<li>Preferred DNS server: <code>8.8.8.8<\/code><\/li>\n<li>Alternate DNS server: <code>8.8.4.4<\/code><\/li>\n<\/ul>\n<\/li>\n<li>Nh\u1ea5n OK \u0111\u1ec3 l\u01b0u l\u1ea1i. B\u1ea1n c\u00f3 th\u1ec3 l\u00e0m t\u01b0\u01a1ng t\u1ef1 cho &#8220;Internet Protocol Version 6 (TCP\/IPv6)&#8221; n\u1ebfu m\u1ea1ng c\u1ee7a b\u1ea1n h\u1ed7 tr\u1ee3 IPv6 (v\u00ed d\u1ee5: Google IPv6 DNS l\u00e0 <code>2001:4860:4860::8888<\/code> v\u00e0 <code>2001:4860:4860::8844<\/code>).<\/li>\n<\/ol>\n<h3><span class=\"ez-toc-section\" id=\"Thay-doi-DNS-tren-may-tinh-macOS\"><\/span>Thay \u0111\u1ed5i DNS tr\u00ean m\u00e1y t\u00ednh macOS<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li>M\u1edf &#8220;System Preferences&#8221; (ho\u1eb7c &#8220;System Settings&#8221; tr\u00ean phi\u00ean b\u1ea3n m\u1edbi).<\/li>\n<li>Nh\u1ea5p v\u00e0o &#8220;Network&#8221;.<\/li>\n<li>Ch\u1ecdn k\u1ebft n\u1ed1i m\u1ea1ng \u0111ang d\u00f9ng (Wi-Fi ho\u1eb7c Ethernet) \u1edf danh s\u00e1ch b\u00ean tr\u00e1i.<\/li>\n<li>Nh\u1ea5n n\u00fat &#8220;Advanced&#8230;&#8221; (ho\u1eb7c &#8220;Details&#8230;&#8221; tr\u00ean phi\u00ean b\u1ea3n m\u1edbi).<\/li>\n<li>Chuy\u1ec3n qua tab &#8220;DNS&#8221;.<\/li>\n<li>Nh\u1ea5n n\u00fat d\u1ea5u c\u1ed9ng (+) \u1edf d\u01b0\u1edbi m\u1ee5c &#8220;DNS Servers&#8221;.<\/li>\n<li>Nh\u1eadp \u0111\u1ecba ch\u1ec9 DNS m\u1edbi (v\u00ed d\u1ee5: <code>1.1.1.1<\/code> cho Cloudflare). Nh\u1ea5n (+) l\u1ea7n n\u1eefa \u0111\u1ec3 th\u00eam \u0111\u1ecba ch\u1ec9 ph\u1ee5 (<code>1.0.0.1<\/code>).<\/li>\n<li>B\u1ea1n c\u00f3 th\u1ec3 ch\u1ecdn c\u00e1c \u0111\u1ecba ch\u1ec9 DNS c\u0169 v\u00e0 nh\u1ea5n d\u1ea5u tr\u1eeb (-) \u0111\u1ec3 x\u00f3a n\u1ebfu mu\u1ed1n.<\/li>\n<li>Nh\u1ea5n &#8220;OK&#8221;, sau \u0111\u00f3 &#8220;Apply&#8221;.<\/li>\n<\/ol>\n<h3><span class=\"ez-toc-section\" id=\"Thay-doi-DNS-tren-dien-thoai-Android\"><\/span>Thay \u0111\u1ed5i DNS tr\u00ean \u0111i\u1ec7n tho\u1ea1i Android<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><i>L\u01b0u \u00fd: Giao di\u1ec7n c\u00f3 th\u1ec3 h\u01a1i kh\u00e1c t\u00f9y h\u00e3ng \u0111i\u1ec7n tho\u1ea1i v\u00e0 phi\u00ean b\u1ea3n Android.<\/i><\/p>\n<p><strong>C\u00e1ch 1: \u0110\u1ed5i DNS cho t\u1eebng m\u1ea1ng Wi-Fi<\/strong><\/p>\n<ol>\n<li>V\u00e0o Settings (C\u00e0i \u0111\u1eb7t) -&gt; Network &amp; internet (M\u1ea1ng &amp; Internet) ho\u1eb7c Connections (K\u1ebft n\u1ed1i) -&gt; Wi-Fi.<\/li>\n<li>Nh\u1ea5n gi\u1eef v\u00e0o t\u00ean m\u1ea1ng Wi-Fi \u0111ang k\u1ebft n\u1ed1i, ch\u1ecdn &#8220;Modify network&#8221; (S\u1eeda \u0111\u1ed5i m\u1ea1ng) ho\u1eb7c nh\u1ea5n v\u00e0o bi\u1ec3u t\u01b0\u1ee3ng b\u00e1nh r\u0103ng\/m\u0169i t\u00ean.<\/li>\n<li>T\u00ecm m\u1ee5c &#8220;IP settings&#8221; (C\u00e0i \u0111\u1eb7t IP), \u0111\u1ed5i t\u1eeb &#8220;DHCP&#8221; sang &#8220;Static&#8221; (T\u0129nh).<\/li>\n<li>B\u1ea1n s\u1ebd th\u1ea5y c\u00e1c \u00f4 DNS 1 v\u00e0 DNS 2. Nh\u1eadp \u0111\u1ecba ch\u1ec9 DNS mu\u1ed1n d\u00f9ng v\u00e0o \u0111\u00e2y (v\u00ed d\u1ee5: <code>8.8.8.8<\/code> v\u00e0 <code>8.8.4.4<\/code>). Gi\u1eef nguy\u00ean c\u00e1c th\u00f4ng s\u1ed1 IP Address, Gateway, Network prefix length n\u1ebfu ch\u00fang \u0111\u00e3 \u0111\u01b0\u1ee3c \u0111i\u1ec1n t\u1ef1 \u0111\u1ed9ng.<\/li>\n<li>Nh\u1ea5n Save (L\u01b0u).<\/li>\n<\/ol>\n<p><strong>C\u00e1ch 2: S\u1eed d\u1ee5ng Private DNS (DNS over TLS &#8211; H\u1ed7 tr\u1ee3 t\u1eeb Android 9 tr\u1edf l\u00ean)<\/strong><\/p>\n<ol>\n<li>V\u00e0o Settings (C\u00e0i \u0111\u1eb7t) -&gt; Network &amp; internet (M\u1ea1ng &amp; Internet) -&gt; Advanced (N\u00e2ng cao) ho\u1eb7c More connection settings (C\u00e0i \u0111\u1eb7t k\u1ebft n\u1ed1i kh\u00e1c).<\/li>\n<li>T\u00ecm m\u1ee5c &#8220;Private DNS&#8221; (DNS ri\u00eang t\u01b0).<\/li>\n<li>Ch\u1ecdn &#8220;Private DNS provider hostname&#8221; (T\u00ean m\u00e1y ch\u1ee7 DNS ri\u00eang t\u01b0).<\/li>\n<li>Nh\u1eadp hostname c\u1ee7a nh\u00e0 cung c\u1ea5p DNS h\u1ed7 tr\u1ee3 DoT. V\u00ed d\u1ee5:\n<ul>\n<li>Cloudflare: <code>1dot1dot1dot1.cloudflare-dns.com<\/code> ho\u1eb7c <code>one.one.one.one<\/code><\/li>\n<li>Google: <code>dns.google<\/code><\/li>\n<\/ul>\n<\/li>\n<li>Nh\u1ea5n Save (L\u01b0u). C\u00e1ch n\u00e0y \u00e1p d\u1ee5ng cho c\u1ea3 Wi-Fi v\u00e0 D\u1eef li\u1ec7u di \u0111\u1ed9ng.<\/li>\n<\/ol>\n<h3><span class=\"ez-toc-section\" id=\"Thay-doi-DNS-tren-iPhoneiPad-iOS\"><\/span><strong>Thay \u0111\u1ed5i DNS tr\u00ean iPhone\/iPad (iOS)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li>M\u1edf Settings (C\u00e0i \u0111\u1eb7t) -&gt; Wi-Fi.<\/li>\n<li>Nh\u1ea5n v\u00e0o bi\u1ec3u t\u01b0\u1ee3ng ch\u1eef &#8220;i&#8221; b\u00ean c\u1ea1nh t\u00ean m\u1ea1ng Wi-Fi \u0111ang k\u1ebft n\u1ed1i.<\/li>\n<li>K\u00e9o xu\u1ed1ng d\u01b0\u1edbi, ch\u1ecdn &#8220;Configure DNS&#8221; (\u0110\u1ecbnh c\u1ea5u h\u00ecnh DNS).<\/li>\n<li>Ch\u1ecdn &#8220;Manual&#8221; (Th\u1ee7 c\u00f4ng).<\/li>\n<li>Nh\u1ea5n &#8220;Add Server&#8221; (Th\u00eam m\u00e1y ch\u1ee7), nh\u1eadp \u0111\u1ecba ch\u1ec9 DNS m\u1edbi (v\u00ed d\u1ee5: <code>1.1.1.1<\/code>). Nh\u1ea5n &#8220;Add Server&#8221; l\u1ea7n n\u1eefa \u0111\u1ec3 th\u00eam \u0111\u1ecba ch\u1ec9 ph\u1ee5 (<code>1.0.0.1<\/code>).<\/li>\n<li>B\u1ea1n c\u00f3 th\u1ec3 vu\u1ed1t sang tr\u00e1i tr\u00ean c\u00e1c \u0111\u1ecba ch\u1ec9 DNS c\u0169 v\u00e0 nh\u1ea5n &#8220;Delete&#8221; (X\u00f3a) n\u1ebfu mu\u1ed1n.<\/li>\n<li>Nh\u1ea5n &#8220;Save&#8221; (L\u01b0u) \u1edf g\u00f3c tr\u00ean b\u00ean ph\u1ea3i.<\/li>\n<\/ol>\n<p>Sau khi thay \u0111\u1ed5i DNS, b\u1ea1n n\u00ean th\u1eed truy c\u1eadp m\u1ed9t v\u00e0i trang web \u0111\u1ec3 ki\u1ec3m tra xem m\u1ecdi th\u1ee9 c\u00f3 ho\u1ea1t \u0111\u1ed9ng b\u00ecnh th\u01b0\u1eddng kh\u00f4ng.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Mot-so-khai-niem-DNS-quan-trong-khac-can-biet\"><\/span>M\u1ed9t s\u1ed1 kh\u00e1i ni\u1ec7m DNS quan tr\u1ecdng kh\u00e1c c\u1ea7n bi\u1ebft<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Ngo\u00e0i c\u00e1c th\u00e0nh ph\u1ea7n v\u00e0 quy tr\u00ecnh c\u01a1 b\u1ea3n, c\u00f3 m\u1ed9t v\u00e0i thu\u1eadt ng\u1eef li\u00ean quan \u0111\u1ebfn DNS m\u00e0 b\u1ea1n c\u0169ng n\u00ean bi\u1ebft \u0111\u1ec3 hi\u1ec3u s\u00e2u h\u01a1n v\u1ec1 c\u00e1ch n\u00f3 ho\u1ea1t \u0111\u1ed9ng v\u00e0 c\u00e1c y\u1ebfu t\u1ed1 \u1ea3nh h\u01b0\u1edfng:<\/p>\n<h3><span class=\"ez-toc-section\" id=\"DNS-Propagation-Su-lan-truyenCap-nhat-DNS\"><\/span>DNS Propagation (S\u1ef1 lan truy\u1ec1n\/C\u1eadp nh\u1eadt DNS)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Khi b\u1ea1n thay \u0111\u1ed5i m\u1ed9t <strong>b\u1ea3n ghi DNS<\/strong> (v\u00ed d\u1ee5: <a href=\"https:\/\/interdata.vn\/blog\/cach-tro-ten-mien-ve-hosting\/\">tr\u1ecf t\u00ean mi\u1ec1n<\/a> \u0111\u1ebfn hosting m\u1edbi), thay \u0111\u1ed5i \u0111\u00f3 kh\u00f4ng c\u00f3 hi\u1ec7u l\u1ef1c ngay l\u1eadp t\u1ee9c tr\u00ean to\u00e0n th\u1ebf gi\u1edbi. <strong>DNS Propagation<\/strong> l\u00e0 qu\u00e1 tr\u00ecnh c\u00e1c m\u00e1y ch\u1ee7 DNS tr\u00ean to\u00e0n c\u1ea7u c\u1eadp nh\u1eadt th\u00f4ng tin m\u1edbi n\u00e0y. Qu\u00e1 tr\u00ecnh n\u00e0y c\u1ea7n th\u1eddi gian v\u00ec c\u00e1c m\u00e1y ch\u1ee7 DNS th\u01b0\u1eddng l\u01b0u tr\u1eef th\u00f4ng tin c\u0169 trong b\u1ed9 nh\u1edb \u0111\u1ec7m (cache) c\u1ee7a ch\u00fang trong m\u1ed9t kho\u1ea3ng th\u1eddi gian nh\u1ea5t \u0111\u1ecbnh.<\/p>\n<p><strong>Th\u1eddi gian c\u1eadp nh\u1eadt DNS<\/strong> (propagation time) c\u00f3 th\u1ec3 dao \u0111\u1ed9ng t\u1eeb v\u00e0i ph\u00fat \u0111\u1ebfn 48 gi\u1edd ho\u1eb7c th\u1eadm ch\u00ed l\u00e2u h\u01a1n, t\u00f9y thu\u1ed9c v\u00e0o nhi\u1ec1u y\u1ebfu t\u1ed1, \u0111\u1eb7c bi\u1ec7t l\u00e0 c\u00e0i \u0111\u1eb7t TTL c\u1ee7a b\u1ea3n ghi DNS c\u0169.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"DNS-Cache-Bo-nho-dem-DNS\"><\/span>DNS Cache (B\u1ed9 nh\u1edb \u0111\u1ec7m DNS)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u1ec3 t\u0103ng t\u1ed1c \u0111\u1ed9 truy c\u1eadp v\u00e0 gi\u1ea3m t\u1ea3i cho h\u1ec7 th\u1ed1ng DNS, th\u00f4ng tin ph\u00e2n gi\u1ea3i t\u00ean mi\u1ec1n th\u01b0\u1eddng \u0111\u01b0\u1ee3c l\u01b0u t\u1ea1m th\u1eddi \u1edf nhi\u1ec1u n\u01a1i: trong <strong>tr\u00ecnh duy\u1ec7t web<\/strong>, trong <strong>h\u1ec7 \u0111i\u1ec1u h\u00e0nh<\/strong> c\u1ee7a m\u00e1y t\u00ednh\/\u0111i\u1ec7n tho\u1ea1i, v\u00e0 tr\u00ean c\u00e1c <strong>DNS Resolver<\/strong>. C\u01a1 ch\u1ebf l\u01b0u tr\u1eef t\u1ea1m th\u1eddi n\u00e0y g\u1ecdi l\u00e0 <strong>DNS Cache<\/strong> hay <strong>b\u1ed9 nh\u1edb \u0111\u1ec7m DNS<\/strong>.<\/p>\n<p>Khi b\u1ea1n truy c\u1eadp l\u1ea1i m\u1ed9t website, thi\u1ebft b\u1ecb s\u1ebd ki\u1ec3m tra cache tr\u01b0\u1edbc. N\u1ebfu th\u00f4ng tin c\u00f2n hi\u1ec7u l\u1ef1c, n\u00f3 s\u1ebd d\u00f9ng ngay IP \u0111\u00e3 l\u01b0u m\u00e0 kh\u00f4ng c\u1ea7n th\u1ef1c hi\u1ec7n l\u1ea1i quy tr\u00ecnh ph\u00e2n gi\u1ea3i \u0111\u1ea7y \u0111\u1ee7. \u0110\u00f4i khi, b\u1ea1n c\u1ea7n <strong>x\u00f3a cache DNS<\/strong> (Flush DNS) tr\u00ean m\u00e1y t\u00ednh (<code>ipconfig \/flushdns<\/code> tr\u00ean Windows) n\u1ebfu g\u1eb7p s\u1ef1 c\u1ed1 truy c\u1eadp sau khi c\u00f3 thay \u0111\u1ed5i DNS.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"TTL-Time-To-Live\"><\/span>TTL (Time To Live)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>TTL (<a href=\"https:\/\/interdata.vn\/blog\/ttl-la-gi\/\">Time To Live<\/a>)<\/strong> l\u00e0 m\u1ed9t gi\u00e1 tr\u1ecb s\u1ed1 (t\u00ednh b\u1eb1ng gi\u00e2y) \u0111\u01b0\u1ee3c thi\u1ebft l\u1eadp cho m\u1ed7i <strong>b\u1ea3n ghi DNS<\/strong>. N\u00f3 ch\u1ec9 \u0111\u1ecbnh kho\u1ea3ng th\u1eddi gian m\u00e0 c\u00e1c DNS Resolver \u0111\u01b0\u1ee3c ph\u00e9p l\u01b0u tr\u1eef (cache) th\u00f4ng tin c\u1ee7a b\u1ea3n ghi \u0111\u00f3 tr\u01b0\u1edbc khi ph\u1ea3i truy v\u1ea5n l\u1ea1i Authoritative Server \u0111\u1ec3 l\u1ea5y th\u00f4ng tin m\u1edbi nh\u1ea5t.<\/p>\n<p>V\u00ed d\u1ee5, TTL 3600 ngh\u0129a l\u00e0 th\u00f4ng tin b\u1ea3n ghi s\u1ebd \u0111\u01b0\u1ee3c cache trong 1 gi\u1edd (3600 gi\u00e2y). TTL th\u1ea5p gi\u00fap thay \u0111\u1ed5i DNS c\u1eadp nh\u1eadt nhanh h\u01a1n (v\u00ec cache h\u1ebft h\u1ea1n s\u1edbm h\u01a1n) nh\u01b0ng t\u1ea1o ra nhi\u1ec1u truy v\u1ea5n DNS h\u01a1n. TTL cao gi\u00fap gi\u1ea3m t\u1ea3i cho DNS server nh\u01b0ng l\u00e0m ch\u1eadm qu\u00e1 tr\u00ecnh <strong>DNS Propagation<\/strong>.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cau-hoi-thuong-gap-ve-DNS-FAQ\"><\/span>C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p v\u1ec1 DNS (FAQ)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 c\u00e2u h\u1ecfi ph\u1ed5 bi\u1ebfn m\u00e0 ng\u01b0\u1eddi d\u00f9ng th\u01b0\u1eddng th\u1eafc m\u1eafc v\u1ec1 DNS:<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Thay-doi-DNS-co-lam-tang-toc-do-mang-khong\"><\/span>Thay \u0111\u1ed5i DNS c\u00f3 l\u00e0m t\u0103ng t\u1ed1c \u0111\u1ed9 m\u1ea1ng kh\u00f4ng?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>C\u00f3 th\u1ec3, nh\u01b0ng kh\u00f4ng ph\u1ea3i l\u00fac n\u00e0o c\u0169ng v\u1eady.<\/strong> Thay \u0111\u1ed5i sang m\u1ed9t Public DNS nhanh h\u01a1n (nh\u01b0 Google ho\u1eb7c Cloudflare) c\u00f3 th\u1ec3 l\u00e0m gi\u1ea3m th\u1eddi gian <strong>ph\u00e2n gi\u1ea3i t\u00ean mi\u1ec1n<\/strong> (DNS lookup time), khi\u1ebfn vi\u1ec7c b\u1eaft \u0111\u1ea7u t\u1ea3i trang web nhanh h\u01a1n m\u1ed9t ch\u00fat. Tuy nhi\u00ean, n\u00f3 kh\u00f4ng l\u00e0m t\u0103ng b\u0103ng th\u00f4ng t\u1ed5ng th\u1ec3 (t\u1ed1c \u0111\u1ed9 download\/upload) c\u1ee7a g\u00f3i c\u01b0\u1edbc Internet b\u1ea1n \u0111ang d\u00f9ng. M\u1ee9c \u0111\u1ed9 c\u1ea3i thi\u1ec7n ph\u1ee5 thu\u1ed9c v\u00e0o t\u1ed1c \u0111\u1ed9 DNS m\u1eb7c \u0111\u1ecbnh c\u1ee7a ISP so v\u1edbi Public DNS b\u1ea1n ch\u1ecdn.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Dung-DNS-cua-Google-8888-hay-Cloudflare-1111-tot-hon\"><\/span>D\u00f9ng DNS c\u1ee7a Google (8.8.8.8) hay Cloudflare (1.1.1.1) t\u1ed1t h\u01a1n?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>C\u1ea3 hai \u0111\u1ec1u l\u00e0 nh\u1eefng l\u1ef1a ch\u1ecdn tuy\u1ec7t v\u1eddi, r\u1ea5t kh\u00f3 n\u00f3i c\u00e1i n\u00e0o &#8220;t\u1ed1t h\u01a1n&#8221; tuy\u1ec7t \u0111\u1ed1i.<\/strong> C\u1ea3 Google DNS v\u00e0 Cloudflare DNS \u0111\u1ec1u cung c\u1ea5p t\u1ed1c \u0111\u1ed9 nhanh v\u00e0 \u0111\u1ed9 tin c\u1eady cao. Cloudflare th\u01b0\u1eddng nh\u1ea5n m\u1ea1nh h\u01a1n v\u1ec1 cam k\u1ebft quy\u1ec1n ri\u00eang t\u01b0 (kh\u00f4ng ghi log truy v\u1ea5n l\u00e2u d\u00e0i). L\u1ef1a ch\u1ecdn t\u1ed1t nh\u1ea5t c\u00f3 th\u1ec3 kh\u00e1c nhau t\u00f9y thu\u1ed9c v\u00e0o v\u1ecb tr\u00ed \u0111\u1ecba l\u00fd v\u00e0 m\u1ea1ng c\u1ee7a b\u1ea1n. B\u1ea1n c\u00f3 th\u1ec3 th\u1eed c\u1ea3 hai ho\u1eb7c d\u00f9ng c\u00e1c c\u00f4ng c\u1ee5 benchmark DNS \u0111\u1ec3 xem c\u00e1i n\u00e0o ph\u1ea3n h\u1ed3i nhanh h\u01a1n t\u1eeb v\u1ecb tr\u00ed c\u1ee7a b\u1ea1n.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Doi-DNS-co-giup-truy-cap-web-bi-chan-khong\"><\/span>\u0110\u1ed5i DNS c\u00f3 gi\u00fap truy c\u1eadp web b\u1ecb ch\u1eb7n kh\u00f4ng?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>C\u00f3 th\u1ec3, n\u1ebfu website \u0111\u00f3 b\u1ecb ch\u1eb7n b\u1eb1ng ph\u01b0\u01a1ng ph\u00e1p ch\u1eb7n DNS.<\/strong> Nhi\u1ec1u ISP ho\u1eb7c qu\u1ed1c gia ch\u1eb7n truy c\u1eadp website b\u1eb1ng c\u00e1ch c\u1ea5u h\u00ecnh DNS server c\u1ee7a h\u1ecd kh\u00f4ng ph\u00e2n gi\u1ea3i t\u00ean mi\u1ec1n c\u1ee7a trang b\u1ecb ch\u1eb7n. Trong tr\u01b0\u1eddng h\u1ee3p n\u00e0y, vi\u1ec7c <strong>\u0111\u1ed5i DNS<\/strong> sang m\u1ed9t Public DNS kh\u00f4ng th\u1ef1c hi\u1ec7n vi\u1ec7c ch\u1eb7n n\u00e0y (nh\u01b0 Google DNS, Cloudflare DNS) s\u1ebd gi\u00fap b\u1ea1n truy c\u1eadp \u0111\u01b0\u1ee3c. Tuy nhi\u00ean, n\u1ebfu website b\u1ecb ch\u1eb7n b\u1eb1ng c\u00e1c ph\u01b0\u01a1ng ph\u00e1p kh\u00e1c (nh\u01b0 ch\u1eb7n \u0111\u1ecba ch\u1ec9 IP, Deep Packet Inspection), vi\u1ec7c \u0111\u1ed5i DNS s\u1ebd kh\u00f4ng hi\u1ec7u qu\u1ea3.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Loi-%E2%80%9CDNS-server-isnt-responding%E2%80%9D-nghia-la-gi-Cach-sua\"><\/span>L\u1ed7i &#8220;DNS server isn&#8217;t responding&#8221; ngh\u0129a l\u00e0 g\u00ec? C\u00e1ch s\u1eeda?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>L\u1ed7i n\u00e0y c\u00f3 ngh\u0129a l\u00e0 m\u00e1y t\u00ednh c\u1ee7a b\u1ea1n kh\u00f4ng th\u1ec3 k\u1ebft n\u1ed1i ho\u1eb7c nh\u1eadn ph\u1ea3n h\u1ed3i t\u1eeb <strong>m\u00e1y ch\u1ee7 DNS<\/strong> m\u00e0 n\u00f3 \u0111ang \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh \u0111\u1ec3 s\u1eed d\u1ee5ng. Nguy\u00ean nh\u00e2n c\u00f3 th\u1ec3 do m\u00e1y ch\u1ee7 DNS \u0111\u00f3 g\u1eb7p s\u1ef1 c\u1ed1, k\u1ebft n\u1ed1i m\u1ea1ng c\u1ee7a b\u1ea1n c\u00f3 v\u1ea5n \u0111\u1ec1, ho\u1eb7c c\u00e0i \u0111\u1eb7t tr\u00ean m\u00e1y t\u00ednh b\u1ecb sai.<\/p>\n<p><strong>C\u00e1ch kh\u1eafc ph\u1ee5c c\u01a1 b\u1ea3n:<\/strong><\/p>\n<ol>\n<li>Ki\u1ec3m tra l\u1ea1i k\u1ebft n\u1ed1i Internet (d\u00e2y m\u1ea1ng, Wi-Fi).<\/li>\n<li>Kh\u1edfi \u0111\u1ed9ng l\u1ea1i modem\/router v\u00e0 m\u00e1y t\u00ednh c\u1ee7a b\u1ea1n.<\/li>\n<li>Th\u1eed <strong>x\u00f3a cache DNS<\/strong>: M\u1edf Command Prompt (v\u1edbi quy\u1ec1n Admin) tr\u00ean Windows v\u00e0 g\u00f5 l\u1ec7nh <code>ipconfig \/flushdns<\/code> r\u1ed3i Enter.<\/li>\n<li><strong>Thay \u0111\u1ed5i DNS Server<\/strong> sang m\u1ed9t Public DNS kh\u00e1c (Google, Cloudflare) theo h\u01b0\u1edbng d\u1eabn \u1edf tr\u00ean.<\/li>\n<li>T\u1ea1m th\u1eddi v\u00f4 hi\u1ec7u h\u00f3a <a href=\"https:\/\/interdata.vn\/blog\/tuong-lua-firewall\/\">t\u01b0\u1eddng l\u1eeda<\/a> ho\u1eb7c ph\u1ea7n m\u1ec1m di\u1ec7t virus \u0111\u1ec3 ki\u1ec3m tra xem ch\u00fang c\u00f3 ch\u1eb7n k\u1ebft n\u1ed1i DNS kh\u00f4ng.<\/li>\n<li>Li\u00ean h\u1ec7 nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 Internet (ISP) n\u1ebfu c\u00e1c b\u01b0\u1edbc tr\u00ean kh\u00f4ng hi\u1ec7u qu\u1ea3.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>B\u1ea1n c\u00f3 bao gi\u1edd th\u1eafc m\u1eafc l\u00e0m th\u1ebf n\u00e0o ch\u1ec9 c\u1ea7n g\u00f5 google.com v\u00e0o tr\u00ecnh duy\u1ec7t l\u00e0 c\u00f3 th\u1ec3 truy c\u1eadp \u0111\u01b0\u1ee3c Google, thay v\u00ec ph\u1ea3i nh\u1edb m\u1ed9t d\u00e3y s\u1ed1 ph\u1ee9c t\u1ea1p? B\u00ed m\u1eadt \u0111\u1eb1ng sau s\u1ef1 ti\u1ec7n l\u1ee3i n\u00e0y ch\u00ednh l\u00e0 DNS. B\u00e0i vi\u1ebft n\u00e0y s\u1ebd gi\u1ea3i th\u00edch DNS l\u00e0 g\u00ec m\u1ed9t c\u00e1ch d\u1ec5<\/p>\n","protected":false},"author":2,"featured_media":27727,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-16738","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hosting"],"_links":{"self":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/16738","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/comments?post=16738"}],"version-history":[{"count":2,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/16738\/revisions"}],"predecessor-version":[{"id":27730,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/16738\/revisions\/27730"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media\/27727"}],"wp:attachment":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media?parent=16738"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/categories?post=16738"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/tags?post=16738"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}