{"id":36841,"date":"2025-12-17T15:13:47","date_gmt":"2025-12-17T08:13:47","guid":{"rendered":"https:\/\/interdata.vn\/blog\/?p=36841"},"modified":"2025-12-17T15:19:07","modified_gmt":"2025-12-17T08:19:07","slug":"reverse-dns-la-gi","status":"publish","type":"post","link":"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/","title":{"rendered":"Reverse DNS l\u00e0 g\u00ec? D\u00f9ng l\u00e0m g\u00ec? Vai tr\u00f2 trong spam email &#038; C\u00e1ch check"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_85 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\/reverse-dns-la-gi\/#Reverse-DNS-la-gi\" >Reverse DNS l\u00e0 g\u00ec?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#PTR-Record-la-gi\" >PTR Record l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/interdata.vn\/blog\/reverse-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-4\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Reverse-DNS-dung-de-lam-gi\" >Reverse DNS d\u00f9ng \u0111\u1ec3 l\u00e0m g\u00ec?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Xac-thuc-va-Bao-mat-mang-Authentication-Security\" >X\u00e1c th\u1ef1c v\u00e0 B\u1ea3o m\u1eadt m\u1ea1ng (Authentication &amp; Security)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Ho-tro-cac-cong-cu-chan-doan-mang\" >H\u1ed7 tr\u1ee3 c\u00e1c c\u00f4ng c\u1ee5 ch\u1ea9n \u0111o\u00e1n m\u1ea1ng<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Kiem-soat-truy-cap-Access-Control\" >Ki\u1ec3m so\u00e1t truy c\u1eadp (Access Control)<\/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\/reverse-dns-la-gi\/#Han-che-spam-dac-biet-trong-he-thong-email\" >H\u1ea1n ch\u1ebf spam, \u0111\u1eb7c bi\u1ec7t trong h\u1ec7 th\u1ed1ng email<\/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\/reverse-dns-la-gi\/#Ho-tro-ghi-log-va-giam-sat-he-thong\" >H\u1ed7 tr\u1ee3 ghi log v\u00e0 gi\u00e1m s\u00e1t h\u1ec7 th\u1ed1ng<\/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\/reverse-dns-la-gi\/#Nang-cao-do-tin-cay-cho-server-va-dich-vu-mang\" >N\u00e2ng cao \u0111\u1ed9 tin c\u1eady cho server v\u00e0 d\u1ecbch v\u1ee5 m\u1ea1ng<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Vai-tro-cua-Reverse-DNS-trong-he-thong-email\" >Vai tr\u00f2 c\u1ee7a Reverse DNS trong h\u1ec7 th\u1ed1ng email<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Co-che-%E2%80%9Cbat-tay%E2%80%9D-giua-cac-Mail-Server\" >C\u01a1 ch\u1ebf &#8220;b\u1eaft tay&#8221; gi\u1eefa c\u00e1c Mail Server<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Reverse-DNS-anh-huong-den-Deliverability-Ty-le-vao-Inbox\" >Reverse DNS \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn Deliverability (T\u1ef7 l\u1ec7 v\u00e0o Inbox)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Reverse-DNS-va-van-de-spam-email\" >Reverse DNS v\u00e0 v\u1ea5n \u0111\u1ec1 spam email<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Tai-sao-Spammer-thuong-khong-co-Reverse-DNS\" >T\u1ea1i sao Spammer th\u01b0\u1eddng kh\u00f4ng c\u00f3 Reverse DNS?<\/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\/reverse-dns-la-gi\/#Reverse-DNS-chong-spam-nhu-the-nao\" >Reverse DNS ch\u1ed1ng spam nh\u01b0 th\u1ebf n\u00e0o?<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Tai-sao-Reverse-DNS-quan-trong-doi-voi-Email-Server\" >T\u1ea1i sao Reverse DNS quan tr\u1ecdng \u0111\u1ed1i v\u1edbi Email Server?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Xay-dung-long-tin-voi-cac-%E2%80%9COng-lon%E2%80%9D-Trust-Score\" >X\u00e2y d\u1ef1ng l\u00f2ng tin v\u1edbi c\u00e1c &#8220;\u00d4ng l\u1edbn&#8221; (Trust Score)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Giam-thieu-nguy-co-bi-gia-mao-Spoofing\" >Gi\u1ea3m thi\u1ec3u nguy c\u01a1 b\u1ecb gi\u1ea3 m\u1ea1o (Spoofing)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#De-dang-Debug-va-khac-phuc-su-co\" >D\u1ec5 d\u00e0ng Debug v\u00e0 kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Cac-thanh-phan-ky-thuat-tao-nen-Reverse-DNS\" >C\u00e1c th\u00e0nh ph\u1ea7n k\u1ef9 thu\u1eadt t\u1ea1o n\u00ean Reverse DNS<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Ban-ghi-PTR-la-gi-trong-Reverse-DNS\" >B\u1ea3n ghi PTR l\u00e0 g\u00ec trong Reverse DNS?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Reverse-Zone-va-khong-gian-luu-tru-DNS-nguoc\" >Reverse Zone v\u00e0 kh\u00f4ng gian l\u01b0u tr\u1eef DNS ng\u01b0\u1ee3c<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Khong-gian-ten-mien-cap-cao-arpa-trong-Reverse-DNS\" >Kh\u00f4ng gian t\u00ean mi\u1ec1n c\u1ea5p cao .arpa trong Reverse DNS<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Co-che-uy-quyen-quan-ly-Reverse-DNS-hoat-dong-nhu-the-nao\" >C\u01a1 ch\u1ebf \u1ee7y quy\u1ec1n qu\u1ea3n l\u00fd Reverse DNS ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Ai-la-nguoi-quan-ly-Reverse-DNS-tai-Viet-Nam\" >Ai l\u00e0 ng\u01b0\u1eddi qu\u1ea3n l\u00fd Reverse DNS t\u1ea1i Vi\u1ec7t Nam?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Nha-cung-cap-dich-vu-ISPIXP-Don-vi-quan-ly-chinh\" >Nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 (ISP\/IXP): \u0110\u01a1n v\u1ecb qu\u1ea3n l\u00fd ch\u00ednh<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Khach-hang-%E2%80%93-nguoi-su-dung-IP-Ben-gui-yeu-cau\" >Kh\u00e1ch h\u00e0ng \u2013 ng\u01b0\u1eddi s\u1eed d\u1ee5ng IP: B\u00ean g\u1eedi y\u00eau c\u1ea7u<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-29\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Truong-hop-dac-biet-Uy-quyen-lai-cho-khach-hang-lon\" >Tr\u01b0\u1eddng h\u1ee3p \u0111\u1eb7c bi\u1ec7t: \u1ee6y quy\u1ec1n l\u1ea1i cho kh\u00e1ch h\u00e0ng l\u1edbn<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-30\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Quyen-quan-ly-Reverse-DNS-va-co-che-chuyen-giao-tai-Viet-Nam\" >Quy\u1ec1n qu\u1ea3n l\u00fd Reverse DNS v\u00e0 c\u01a1 ch\u1ebf chuy\u1ec3n giao t\u1ea1i Vi\u1ec7t Nam<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-31\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Phan-biet-Forward-DNS-va-Reverse-DNS\" >Ph\u00e2n bi\u1ec7t Forward DNS v\u00e0 Reverse DNS<\/a><\/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\/reverse-dns-la-gi\/#Dieu-gi-xay-ra-neu-IP-khong-co-Reverse-DNS\" >\u0110i\u1ec1u g\u00ec x\u1ea3y ra n\u1ebfu IP kh\u00f4ng c\u00f3 Reverse DNS?<\/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\/reverse-dns-la-gi\/#Email-bi-tu-choi-thang-thung-Bounce-Back\" >Email b\u1ecb t\u1eeb ch\u1ed1i th\u1eb3ng th\u1eebng (Bounce Back)<\/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\/reverse-dns-la-gi\/#Email-vao-Spam-folder\" >Email v\u00e0o Spam folder<\/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\/reverse-dns-la-gi\/#Gian-doan-giao-dich-kinh-doanh\" >Gi\u00e1n \u0111o\u1ea1n giao d\u1ecbch kinh doanh<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-36\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Reverse-DNS-co-bat-buoc-khong\" >Reverse DNS c\u00f3 b\u1eaft bu\u1ed9c kh\u00f4ng?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-37\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Doi-voi-nguoi-dung-Internet-thong-thuong\" >\u0110\u1ed1i v\u1edbi ng\u01b0\u1eddi d\u00f9ng Internet th\u00f4ng th\u01b0\u1eddng<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-38\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Doi-voi-Web-Server\" >\u0110\u1ed1i v\u1edbi Web Server<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-39\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Doi-voi-Mail-Server-BAT-BUOC\" >\u0110\u1ed1i v\u1edbi Mail Server (B\u1eaeT BU\u1ed8C)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-40\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Khi-nao-can-su-dung-Reverse-DNS\" >Khi n\u00e0o c\u1ea7n s\u1eed d\u1ee5ng Reverse DNS?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-41\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Cach-cau-hinh-Reverse-DNS-rDNS-cho-dia-chi-IP\" >C\u00e1ch c\u1ea5u h\u00ecnh Reverse DNS (rDNS) cho \u0111\u1ecba ch\u1ec9 IP<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-42\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Cac-cong-cu-kiem-tra-Reverse-DNS-Reverse-DNS-Lookup\" >C\u00e1c c\u00f4ng c\u1ee5 ki\u1ec3m tra Reverse DNS (Reverse DNS Lookup)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-43\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Kiem-tra-Reverse-DNS-tren-Windows-bang-nslookup\" >Ki\u1ec3m tra Reverse DNS tr\u00ean Windows b\u1eb1ng nslookup<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-44\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Kiem-tra-Reverse-DNS-tren-LinuxUnix-bang-lenh-host\" >Ki\u1ec3m tra Reverse DNS tr\u00ean Linux\/Unix b\u1eb1ng l\u1ec7nh host<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-45\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Tra-cuu-Reverse-DNS-bang-cong-cu-truc-tuyen\" >Tra c\u1ee9u Reverse DNS b\u1eb1ng c\u00f4ng c\u1ee5 tr\u1ef1c tuy\u1ebfn<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-46\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Cac-loi-Reverse-DNS-thuong-gap-va-huong-khac-phuc\" >C\u00e1c l\u1ed7i Reverse DNS th\u01b0\u1eddng g\u1eb7p v\u00e0 h\u01b0\u1edbng kh\u1eafc ph\u1ee5c<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-47\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Khong-ton-tai-ban-ghi-PTR\" >Kh\u00f4ng t\u1ed3n t\u1ea1i b\u1ea3n ghi PTR<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-48\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Ban-ghi-PTR-khong-khop-voi-A-record\" >B\u1ea3n ghi PTR kh\u00f4ng kh\u1edbp v\u1edbi A record<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-49\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Dia-chi-IP-thuoc-nha-mang-khong-ho-tro-Reverse-DNS\" >\u0110\u1ecba ch\u1ec9 IP thu\u1ed9c nh\u00e0 m\u1ea1ng kh\u00f4ng h\u1ed7 tr\u1ee3 Reverse DNS<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-50\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Server-email-bi-danh-dau-spam-do-Reverse-DNS-sai\" >Server email b\u1ecb \u0111\u00e1nh d\u1ea5u spam do Reverse DNS sai<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-51\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Reverse-DNS-va-nhung-luu-y-quan-trong-khi-su-dung\" >Reverse DNS v\u00e0 nh\u1eefng l\u01b0u \u00fd quan tr\u1ecdng khi s\u1eed d\u1ee5ng<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-52\" href=\"https:\/\/interdata.vn\/blog\/reverse-dns-la-gi\/#Ket-luan\" >K\u1ebft lu\u1eadn<\/a><\/li><\/ul><\/nav><\/div>\n<p>Khi g\u1eedi email t\u1eeb m\u1ed9t server nh\u01b0ng th\u01b0 l\u1ea1i li\u00ean t\u1ee5c r\u01a1i v\u00e0o spam, ho\u1eb7c khi c\u1ea5u h\u00ecnh VPS v\u00e0 \u0111\u01b0\u1ee3c y\u00eau c\u1ea7u thi\u1ebft l\u1eadp <strong>PTR record<\/strong>, nhi\u1ec1u ng\u01b0\u1eddi b\u1eaft \u0111\u1ea7u b\u1eaft g\u1eb7p thu\u1eadt ng\u1eef &#8220;<strong>Reverse DNS<\/strong>&#8221; v\u00e0 th\u1eafc m\u1eafc: <strong>Reverse DNS l\u00e0 g\u00ec v\u00e0 v\u00ec sao n\u00f3 l\u1ea1i quan tr\u1ecdng \u0111\u1ebfn v\u1eady? <\/strong>Tr\u00ean th\u1ef1c t\u1ebf, Reverse DNS kh\u00f4ng ph\u1ea3i l\u00e0 kh\u00e1i ni\u1ec7m qu\u00e1 ph\u1ee9c t\u1ea1p, nh\u01b0ng l\u1ea1i \u0111\u00f3ng vai tr\u00f2 then ch\u1ed1t trong vi\u1ec7c <strong>x\u00e1c th\u1ef1c m\u00e1y ch\u1ee7, n\u00e2ng cao uy t\u00edn IP v\u00e0 \u0111\u1ea3m b\u1ea3o email \u0111\u01b0\u1ee3c g\u1eedi \u0111i an to\u00e0n<\/strong>. Hi\u1ec3u \u0111\u00fang v\u1ec1 Reverse DNS s\u1ebd gi\u00fap b\u1ea1n tr\u00e1nh \u0111\u01b0\u1ee3c nhi\u1ec1u l\u1ed7i ph\u1ed5 bi\u1ebfn khi v\u1eadn h\u00e0nh server, \u0111\u1eb7c bi\u1ec7t l\u00e0 h\u1ec7 th\u1ed1ng email.<\/p>\n<p>B\u00e0i vi\u1ebft chuy\u00ean s\u00e2u n\u00e0y t\u1eeb InterData s\u1ebd gi\u1ea3i m\u00e3 to\u00e0n b\u1ed9 v\u1ec1 Reverse DNS, t\u1eeb th\u00e0nh ph\u1ea7n, vai tr\u00f2 c\u1ee7a Reverse DNS trong h\u1ec7 th\u1ed1ng email, ph\u00e2n bi\u1ec7t Forward DNS v\u00e0 Reverse DNS v\u00e0 g\u1ee3i \u00fd c\u00f4ng c\u1ee5 ki\u1ec3m tra Reverse DNS gi\u00fap b\u1ea1n t\u1ed1i \u01b0u h\u00f3a t\u1ef7 l\u1ec7 v\u00e0o Inbox cho h\u1ec7 th\u1ed1ng c\u1ee7a m\u00ecnh.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Reverse-DNS-la-gi\"><\/span>Reverse DNS l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>Reverse DNS<\/strong> (vi\u1ebft t\u1eaft l\u00e0 rDNS), hay c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi b\u1eb1ng t\u00ean ti\u1ebfng Vi\u1ec7t l\u00e0 DNS ng\u01b0\u1ee3c, l\u00e0 m\u1ed9t qu\u00e1 tr\u00ecnh ph\u00e2n gi\u1ea3i \u0111\u1ecba ch\u1ec9 IP (Internet Protocol) th\u00e0nh m\u1ed9t t\u00ean mi\u1ec1n (Hostname) t\u01b0\u01a1ng \u1ee9ng.<\/p>\n<p>H\u1ea7u h\u1ebft ch\u00fang ta \u0111\u1ec1u quen thu\u1ed9c v\u1edbi DNS th\u00f4ng th\u01b0\u1eddng (Forward DNS) \u2013 n\u01a1i m\u00e0 t\u00ean mi\u1ec1n d\u1ec5 nh\u1edb (v\u00ed d\u1ee5: interdata.vn) \u0111\u01b0\u1ee3c chuy\u1ec3n \u0111\u1ed5i th\u00e0nh \u0111\u1ecba ch\u1ec9 IP m\u00e1y ch\u1ee7 \u0111\u1ec3 tr\u00ecnh duy\u1ec7t c\u00f3 th\u1ec3 k\u1ebft n\u1ed1i. Ng\u01b0\u1ee3c l\u1ea1i, Reverse DNS th\u1ef1c hi\u1ec7n quy tr\u00ecnh \u0111\u1ed1i ngh\u1ecbch ho\u00e0n to\u00e0n: truy v\u1ea5n t\u1eeb \u0111\u1ecba ch\u1ec9 IP \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh xem t\u00ean mi\u1ec1n n\u00e0o \u0111ang \u0111\u1ee9ng sau \u0111\u1ecba ch\u1ec9 \u0111\u00f3.<\/p>\n<p>Hi\u1ec3u m\u1ed9t c\u00e1ch \u0111\u01a1n gi\u1ea3n nh\u1ea5t v\u1ec1 <strong>Reverse DNS<\/strong>: l\u00e0\u00a0c\u00e1ch Internet x\u00e1c minh &#8220;danh t\u00ednh&#8221; c\u1ee7a m\u1ed9t \u0111\u1ecba ch\u1ec9 IP. N\u1ebfu m\u1ed9t IP tuy\u00ean b\u1ed1 n\u00f3 thu\u1ed9c v\u1ec1 m\u1ed9t t\u00ean mi\u1ec1n n\u00e0o \u0111\u00f3, Reverse DNS l\u00e0 c\u01a1 ch\u1ebf \u0111\u1ec3 ki\u1ec3m ch\u1ee9ng l\u1eddi tuy\u00ean b\u1ed1 n\u00e0y.<\/p>\n<figure id=\"attachment_36844\" aria-describedby=\"caption-attachment-36844\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-36844\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-la-gi.jpg\" alt=\"Reverse DNS l\u00e0 g\u00ec?\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-la-gi.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-la-gi-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-la-gi-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-36844\" class=\"wp-caption-text\">Reverse DNS l\u00e0 g\u00ec?<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"PTR-Record-la-gi\"><\/span>PTR Record l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Kh\u00f4ng th\u1ec3 ch\u1ec9 gi\u1ea3i th\u00edch <strong>Reverse DNS<\/strong>\u00a0m\u00e0 thi\u1ebfu \u0111i th\u00e0nh ph\u1ea7n quan tr\u1ecdng nh\u1ea5t c\u1ee7a n\u00f3: PTR Record (Pointer Record). \u0110\u00e2y l\u00e0 b\u1ea3n ghi con tr\u1ecf, \u0111\u00f3ng vai tr\u00f2 tr\u00e1i tim trong c\u01a1 ch\u1ebf ho\u1ea1t \u0111\u1ed9ng c\u1ee7a DNS ng\u01b0\u1ee3c.<\/p>\n<p>N\u1ebfu trong DNS thu\u1eadn (Forward DNS), ch\u00fang ta s\u1eed d\u1ee5ng b\u1ea3n ghi lo\u1ea1i <strong>A<\/strong> (\u0111\u1ed1i v\u1edbi IPv4) ho\u1eb7c <strong>AAAA<\/strong> (\u0111\u1ed1i v\u1edbi IPv6) \u0111\u1ec3 tr\u1ecf t\u00ean mi\u1ec1n v\u1ec1 IP, th\u00ec trong DNS ng\u01b0\u1ee3c, ch\u00fang ta s\u1eed d\u1ee5ng b\u1ea3n ghi <strong>PTR<\/strong> \u0111\u1ec3 \u00e1nh x\u1ea1 IP v\u1ec1 t\u00ean mi\u1ec1n.<\/p>\n<p>B\u1ea1n kh\u00f4ng th\u1ec3 t\u1ef1 t\u1ea1o b\u1ea3n ghi PTR tr\u00ean trang qu\u1ea3n l\u00fd t\u00ean mi\u1ec1n th\u00f4ng th\u01b0\u1eddng (nh\u01b0 n\u01a1i b\u1ea1n mua domain). B\u1ea3n ghi n\u00e0y ph\u1ea3i \u0111\u01b0\u1ee3c t\u1ea1o v\u00e0 qu\u1ea3n l\u00fd b\u1edfi \u0111\u01a1n v\u1ecb cung c\u1ea5p \u0111\u1ecba ch\u1ec9 IP cho b\u1ea1n (ISP ho\u1eb7c nh\u00e0 cung c\u1ea5p Hosting\/VPS nh\u01b0 InterData). \u0110\u00e2y l\u00e0 \u0111i\u1ec3m m\u1ea5u ch\u1ed1t khi\u1ebfn nhi\u1ec1u ng\u01b0\u1eddi m\u1edbi b\u1eaft \u0111\u1ea7u c\u1ea3m th\u1ea5y b\u1ed1i r\u1ed1i.<\/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>\u0110\u1ec3 gi\u00fap b\u1ea1n h\u00ecnh dung r\u00f5 h\u01a1n <strong>t\u00ean mi\u1ec1n ng\u01b0\u1ee3c<\/strong>, h\u00e3y t\u01b0\u1edfng t\u01b0\u1ee3ng v\u1ec1 danh b\u1ea1 \u0111i\u1ec7n tho\u1ea1i tr\u00ean smartphone c\u1ee7a b\u1ea1n:<\/p>\n<ul>\n<li><strong>DNS thu\u1eadn (Forward DNS):<\/strong> B\u1ea1n mu\u1ed1n g\u1ecdi cho &#8220;Nguy\u1ec5n V\u0103n A&#8221;. B\u1ea1n g\u00f5 t\u00ean &#8220;Nguy\u1ec5n V\u0103n A&#8221; v\u00e0o danh b\u1ea1, \u0111i\u1ec7n tho\u1ea1i s\u1ebd hi\u1ec3n th\u1ecb s\u1ed1 &#8220;0909.xxx.xxx&#8221; \u0111\u1ec3 th\u1ef1c hi\u1ec7n cu\u1ed9c g\u1ecdi. \u0110\u00e2y l\u00e0 c\u00e1ch ng\u01b0\u1eddi d\u00f9ng ph\u1ed5 th\u00f4ng s\u1eed d\u1ee5ng Internet: g\u00f5 t\u00ean mi\u1ec1n \u0111\u1ec3 \u0111\u1ebfn \u0111\u1ecba ch\u1ec9 IP c\u1ee7a web server.<\/li>\n<li><strong>DNS ng\u01b0\u1ee3c (Reverse DNS):<\/strong> B\u1ea1n nh\u1eadn \u0111\u01b0\u1ee3c m\u1ed9t cu\u1ed9c g\u1ecdi t\u1eeb s\u1ed1 l\u1ea1 &#8220;0909.xxx.xxx&#8221;. B\u1ea1n mu\u1ed1n bi\u1ebft ai \u0111ang g\u1ecdi \u0111\u1ec3 quy\u1ebft \u0111\u1ecbnh c\u00f3 nghe m\u00e1y hay kh\u00f4ng. B\u1ea1n tra c\u1ee9u s\u1ed1 n\u00e0y tr\u00ean Zalo ho\u1eb7c c\u00e1c ph\u1ea7n m\u1ec1m nh\u1eadn di\u1ec7n, v\u00e0 h\u1ec7 th\u1ed1ng tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3: &#8220;\u0110\u00e2y l\u00e0 s\u1ed1 c\u1ee7a Nguy\u1ec5n V\u0103n A&#8221;. N\u1ebfu k\u1ebft qu\u1ea3 tr\u1ea3 v\u1ec1 l\u00e0 &#8220;S\u1ed1 r\u00e1c&#8221; ho\u1eb7c &#8220;L\u1eeba \u0111\u1ea3o&#8221;, b\u1ea1n s\u1ebd ch\u1eb7n ngay l\u1eadp t\u1ee9c.<\/li>\n<\/ul>\n<p>Trong th\u1ebf gi\u1edbi Internet, c\u00e1c m\u00e1y ch\u1ee7 nh\u1eadn email (nh\u01b0 Gmail Server) \u0111\u00f3ng vai tr\u00f2 l\u00e0 ng\u01b0\u1eddi nh\u1eadn cu\u1ed9c g\u1ecdi. Khi m\u00e1y ch\u1ee7 c\u1ee7a b\u1ea1n (IP l\u1ea1) g\u1eedi email \u0111\u1ebfn, Gmail s\u1ebd th\u1ef1c hi\u1ec7n tra c\u1ee9u <strong>Reverse DNS<\/strong>\u00a0\u0111\u1ed1i v\u1edbi IP \u0111\u00f3. N\u1ebfu IP c\u1ee7a b\u1ea1n c\u00f3 &#8220;t\u00ean tu\u1ed5i&#8221; r\u00f5 r\u00e0ng (c\u00f3 rDNS tr\u1ecf v\u1ec1 hostname h\u1ee3p l\u1ec7), Gmail s\u1ebd tin t\u01b0\u1edfng h\u01a1n. Ng\u01b0\u1ee3c l\u1ea1i, n\u1ebfu kh\u00f4ng tra ra t\u00ean, IP c\u1ee7a b\u1ea1n b\u1ecb coi l\u00e0 k\u1ebb l\u1ea1 m\u1eb7t \u0111\u00e1ng ng\u1edd.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Reverse-DNS-dung-de-lam-gi\"><\/span>Reverse DNS d\u00f9ng \u0111\u1ec3 l\u00e0m g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Kh\u00f4ng ph\u1ea3i ng\u1eabu nhi\u00ean m\u00e0 rDNS \u0111\u01b0\u1ee3c coi l\u00e0 m\u1ed9t ti\u00eau chu\u1ea9n c\u1ea5u h\u00ecnh m\u1ea1ng chuy\u00ean nghi\u1ec7p. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 nh\u1eefng m\u1ee5c \u0111\u00edch s\u1eed d\u1ee5ng ch\u00ednh c\u1ee7a k\u1ef9 thu\u1eadt rDNS\u00a0trong h\u1ea1 t\u1ea7ng m\u1ea1ng hi\u1ec7n \u0111\u1ea1i.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Xac-thuc-va-Bao-mat-mang-Authentication-Security\"><\/span>X\u00e1c th\u1ef1c v\u00e0 B\u1ea3o m\u1eadt m\u1ea1ng (Authentication &amp; Security)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u1ee5c \u0111\u00edch l\u1edbn nh\u1ea5t c\u1ee7a rDNS l\u00e0 x\u00e1c th\u1ef1c. Trong m\u00f4i tr\u01b0\u1eddng Internet \u0111\u1ea7y r\u1eaby r\u1ee7i ro, vi\u1ec7c bi\u1ebft ch\u00ednh x\u00e1c m\u1ed9t \u0111\u1ecba ch\u1ec9 IP thu\u1ed9c v\u1ec1 t\u1ed5 ch\u1ee9c hay c\u00e1 nh\u00e2n n\u00e0o l\u00e0 v\u00f4 c\u00f9ng quan tr\u1ecdng. C\u00e1c h\u1ec7 th\u1ed1ng t\u01b0\u1eddng l\u1eeda (Firewall) v\u00e0 c\u00e1c c\u00f4ng c\u1ee5 gi\u00e1m s\u00e1t m\u1ea1ng th\u01b0\u1eddng xuy\u00ean s\u1eed d\u1ee5ng rDNS \u0111\u1ec3 ghi l\u1ea1i nh\u1eadt k\u00fd (log).<\/p>\n<p>Thay v\u00ec nh\u00ecn v\u00e0o m\u1ed9t d\u00e3y s\u1ed1 kh\u00f4 khan nh\u01b0 192.168.1.1 trong file log, qu\u1ea3n tr\u1ecb vi\u00ean c\u00f3 th\u1ec3 nh\u00ecn th\u1ea5y mail.interdata.vn. \u0110i\u1ec1u n\u00e0y gi\u00fap vi\u1ec7c nh\u1eadn di\u1ec7n ngu\u1ed3n g\u1ed1c c\u00e1c cu\u1ed9c t\u1ea5n c\u00f4ng ho\u1eb7c l\u01b0u l\u01b0\u1ee3ng truy c\u1eadp b\u1ea5t th\u01b0\u1eddng tr\u1edf n\u00ean nhanh ch\u00f3ng v\u00e0 ch\u00ednh x\u00e1c h\u01a1n r\u1ea5t nhi\u1ec1u.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Ho-tro-cac-cong-cu-chan-doan-mang\"><\/span>H\u1ed7 tr\u1ee3 c\u00e1c c\u00f4ng c\u1ee5 ch\u1ea9n \u0111o\u00e1n m\u1ea1ng<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>C\u00e1c k\u1ef9 s\u01b0 h\u1ec7 th\u1ed1ng th\u01b0\u1eddng xuy\u00ean s\u1eed d\u1ee5ng c\u00e1c l\u1ec7nh nh\u01b0 traceroute (tr\u00ean Linux\/Mac) hay tracert (tr\u00ean Windows) \u0111\u1ec3 ki\u1ec3m tra \u0111\u01b0\u1eddng \u0111i c\u1ee7a g\u00f3i tin. Khi rDNS \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh ch\u00ednh x\u00e1c, k\u1ebft qu\u1ea3 tr\u1ea3 v\u1ec1 s\u1ebd hi\u1ec3n th\u1ecb t\u00ean c\u1ee7a c\u00e1c router m\u00e0 g\u00f3i tin \u0111i qua thay v\u00ec ch\u1ec9 l\u00e0 c\u00e1c \u0111\u1ecba ch\u1ec9 IP.<\/p>\n<p>Vi\u1ec7c n\u00e0y gi\u00fap ng\u01b0\u1eddi qu\u1ea3n tr\u1ecb d\u1ec5 d\u00e0ng h\u00ecnh dung ra s\u01a1 \u0111\u1ed3 m\u1ea1ng v\u1eadt l\u00fd v\u00e0 v\u1ecb tr\u00ed \u0111\u1ecba l\u00fd c\u1ee7a c\u00e1c n\u00fat m\u1ea1ng, t\u1eeb \u0111\u00f3 khoanh v\u00f9ng s\u1ef1 c\u1ed1 \u0111\u01b0\u1eddng truy\u1ec1n hi\u1ec7u qu\u1ea3 h\u01a1n.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Kiem-soat-truy-cap-Access-Control\"><\/span>Ki\u1ec3m so\u00e1t truy c\u1eadp (Access Control)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u1ed9t s\u1ed1 d\u1ecbch v\u1ee5 m\u1ea1ng c\u0169 ho\u1eb7c c\u00e1c h\u1ec7 th\u1ed1ng n\u1ed9i b\u1ed9 b\u1ea3o m\u1eadt cao (nh\u01b0 SSH server, Database server) c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh \u0111\u1ec3 ch\u1ec9 cho ph\u00e9p k\u1ebft n\u1ed1i t\u1eeb c\u00e1c t\u00ean mi\u1ec1n c\u1ee5 th\u1ec3 thay v\u00ec IP. Khi \u0111\u00f3, h\u1ec7 th\u1ed1ng s\u1ebd th\u1ef1c hi\u1ec7n tra c\u1ee9u rDNS \u0111\u1ed1i v\u1edbi IP k\u1ebft n\u1ed1i \u0111\u1ebfn. N\u1ebfu t\u00ean mi\u1ec1n tr\u1ea3 v\u1ec1 kh\u1edbp v\u1edbi danh s\u00e1ch cho ph\u00e9p (Allowlist), k\u1ebft n\u1ed1i m\u1edbi \u0111\u01b0\u1ee3c ch\u1ea5p nh\u1eadn.<\/p>\n<p>D\u00f9 ph\u01b0\u01a1ng ph\u00e1p n\u00e0y ng\u00e0y nay \u00edt ph\u1ed5 bi\u1ebfn h\u01a1n do v\u1ea5n \u0111\u1ec1 v\u1ec1 hi\u1ec7u n\u0103ng DNS, nh\u01b0ng n\u00f3 v\u1eabn l\u00e0 m\u1ed9t l\u1edbp b\u1ea3o v\u1ec7 b\u1ed5 sung \u1edf nhi\u1ec1u h\u1ec7 th\u1ed1ng legacy.<\/p>\n<figure id=\"attachment_36845\" aria-describedby=\"caption-attachment-36845\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-36845\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-dung-de-lam-gi.jpg\" alt=\"Reverse DNS d\u00f9ng \u0111\u1ec3 l\u00e0m g\u00ec?\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-dung-de-lam-gi.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-dung-de-lam-gi-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-dung-de-lam-gi-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-36845\" class=\"wp-caption-text\">Reverse DNS d\u00f9ng \u0111\u1ec3 l\u00e0m g\u00ec?<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"Han-che-spam-dac-biet-trong-he-thong-email\"><\/span>H\u1ea1n ch\u1ebf spam, \u0111\u1eb7c bi\u1ec7t trong h\u1ec7 th\u1ed1ng email<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Trong h\u1ec7 th\u1ed1ng email, Reverse DNS l\u00e0 m\u1ed9t ti\u00eau ch\u00ed quan tr\u1ecdng \u0111\u1ec3 \u0111\u00e1nh gi\u00e1 <strong>uy t\u00edn IP g\u1eedi<\/strong>. N\u1ebfu m\u1ed9t mail server kh\u00f4ng c\u00f3 Reverse DNS ho\u1eb7c Reverse DNS kh\u00f4ng kh\u1edbp v\u1edbi t\u00ean mi\u1ec1n g\u1eedi, email r\u1ea5t d\u1ec5:<\/p>\n<ul>\n<li>B\u1ecb \u0111\u00e1nh d\u1ea5u spam<\/li>\n<li>B\u1ecb t\u1eeb ch\u1ed1i ngay t\u1eeb \u0111\u1ea7u<\/li>\n<li>Kh\u00f4ng \u0111\u1ebfn \u0111\u01b0\u1ee3c h\u1ed9p th\u01b0 ng\u01b0\u1eddi nh\u1eadn<\/li>\n<\/ul>\n<p>V\u00ec v\u1eady, c\u1ea5u h\u00ecnh Reverse DNS \u0111\u00fang c\u00e1ch gi\u00fap <strong>gi\u1ea3m nguy c\u01a1 email r\u01a1i v\u00e0o spam<\/strong> v\u00e0 c\u1ea3i thi\u1ec7n t\u1ef7 l\u1ec7 v\u00e0o inbox.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Ho-tro-ghi-log-va-giam-sat-he-thong\"><\/span>H\u1ed7 tr\u1ee3 ghi log v\u00e0 gi\u00e1m s\u00e1t h\u1ec7 th\u1ed1ng<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Reverse DNS gi\u00fap qu\u1ea3n tr\u1ecb vi\u00ean d\u1ec5 d\u00e0ng <strong>\u0111\u1ecdc v\u00e0 ph\u00e2n t\u00edch log<\/strong> h\u01a1n. Thay v\u00ec ch\u1ec9 th\u1ea5y c\u00e1c \u0111\u1ecba ch\u1ec9 IP kh\u00f3 nh\u1edb, h\u1ec7 th\u1ed1ng c\u00f3 th\u1ec3 hi\u1ec3n th\u1ecb t\u00ean mi\u1ec1n t\u01b0\u01a1ng \u1ee9ng, gi\u00fap vi\u1ec7c theo d\u00f5i, ki\u1ec3m tra v\u00e0 x\u1eed l\u00fd s\u1ef1 c\u1ed1 tr\u1edf n\u00ean thu\u1eadn ti\u1ec7n h\u01a1n.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Nang-cao-do-tin-cay-cho-server-va-dich-vu-mang\"><\/span>N\u00e2ng cao \u0111\u1ed9 tin c\u1eady cho server v\u00e0 d\u1ecbch v\u1ee5 m\u1ea1ng<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u1ed9t m\u00e1y ch\u1ee7 c\u00f3 Reverse DNS h\u1ee3p l\u1ec7 th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111\u00e1nh gi\u00e1 l\u00e0 <strong>\u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh b\u00e0i b\u1ea3n v\u00e0 chuy\u00ean nghi\u1ec7p<\/strong>. \u0110i\u1ec1u n\u00e0y kh\u00f4ng ch\u1ec9 quan tr\u1ecdng v\u1edbi email server m\u00e0 c\u00f2n c\u00f3 \u00fd ngh\u0129a trong nhi\u1ec1u d\u1ecbch v\u1ee5 m\u1ea1ng kh\u00e1c nh\u01b0:<\/p>\n<ul>\n<li>K\u1ebft n\u1ed1i API<\/li>\n<li>D\u1ecbch v\u1ee5 x\u00e1c th\u1ef1c<\/li>\n<li>M\u1ed9t s\u1ed1 h\u1ec7 th\u1ed1ng b\u1ea3o m\u1eadt v\u00e0 firewall<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Vai-tro-cua-Reverse-DNS-trong-he-thong-email\"><\/span>Vai tr\u00f2 c\u1ee7a Reverse DNS trong h\u1ec7 th\u1ed1ng email<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u00e2y ch\u00ednh l\u00e0 ph\u1ea7n quan tr\u1ecdng nh\u1ea5t gi\u1ea3i th\u00edch t\u1ea1i sao b\u1ea1n c\u1ea7n quan t\u00e2m <strong>Reverse DNS l\u00e0 g\u00ec<\/strong>. \u0110\u1ed1i v\u1edbi h\u1ec7 th\u1ed1ng th\u01b0 \u0111i\u1ec7n t\u1eed (Email Server), rDNS kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t t\u00f9y ch\u1ecdn &#8220;c\u00f3 th\u00ec t\u1ed1t&#8221;, m\u00e0 l\u00e0 m\u1ed9t y\u00eau c\u1ea7u s\u1ed1ng c\u00f2n.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Co-che-%E2%80%9Cbat-tay%E2%80%9D-giua-cac-Mail-Server\"><\/span>C\u01a1 ch\u1ebf &#8220;b\u1eaft tay&#8221; gi\u1eefa c\u00e1c Mail Server<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Giao th\u1ee9c g\u1eedi nh\u1eadn email (SMTP) ho\u1ea1t \u0111\u1ed9ng d\u1ef1a tr\u00ean s\u1ef1 tin c\u1eady. Khi Mail Server A (c\u1ee7a b\u1ea1n) k\u1ebft n\u1ed1i \u0111\u1ebfn Mail Server B (c\u1ee7a \u0111\u1ed1i t\u00e1c) \u0111\u1ec3 g\u1eedi th\u01b0, cu\u1ed9c h\u1ed9i tho\u1ea1i s\u1ebd di\u1ec5n ra nh\u01b0 sau:<\/p>\n<ol>\n<li><strong>Server A:<\/strong> &#8220;Xin ch\u00e0o, t\u00f4i l\u00e0 mail.congtyban.com, t\u00f4i mu\u1ed1n g\u1eedi th\u01b0 t\u1eeb IP 1.2.3.4.&#8221;<\/li>\n<li><strong>Server B:<\/strong> &#8220;Khoan \u0111\u00e3, \u0111\u1ec3 t\u00f4i ki\u1ec3m tra xem anh c\u00f3 n\u00f3i th\u1eadt kh\u00f4ng.&#8221;<\/li>\n<li><strong>Server B (Th\u1ef1c hi\u1ec7n rDNS):<\/strong> &#8220;H\u1ee1i h\u1ec7 th\u1ed1ng DNS, IP 1.2.3.4 n\u00e0y c\u00f3 t\u00ean mi\u1ec1n l\u00e0 g\u00ec?&#8221;<\/li>\n<li><strong>DNS:<\/strong> &#8220;IP 1.2.3.4 c\u00f3 t\u00ean l\u00e0 mail.congtyban.com.&#8221;<\/li>\n<li><strong>Server B:<\/strong> &#8220;Ok, th\u00f4ng tin kh\u1edbp. T\u00f4i ch\u1ea5p nh\u1eadn k\u1ebft n\u1ed1i.&#8221;<\/li>\n<\/ol>\n<p>N\u1ebfu \u1edf b\u01b0\u1edbc 4, DNS tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 kh\u00e1c ho\u1eb7c kh\u00f4ng tr\u1ea3 v\u1ec1 g\u00ec c\u1ea3 (NXDOMAIN), Server B s\u1ebd nghi ng\u1edd Server A \u0111ang gi\u1ea3 danh. \u0110\u00e2y l\u00e0 l\u00fd do c\u1ed1t l\u00f5i khi\u1ebfn c\u00e1c qu\u1ea3n tr\u1ecb vi\u00ean ph\u1ea3i hi\u1ec3u t\u01b0\u1eddng t\u1eadn <strong>Reverse DNS<\/strong>\u00a0\u0111\u1ec3 c\u1ea5u h\u00ecnh cho \u0111\u00fang.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Reverse-DNS-anh-huong-den-Deliverability-Ty-le-vao-Inbox\"><\/span>Reverse DNS \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn Deliverability (T\u1ef7 l\u1ec7 v\u00e0o Inbox)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Trong thu\u1eadt ng\u1eef Email Marketing, Deliverability l\u00e0 t\u1ef7 l\u1ec7 th\u01b0 g\u1eedi \u0111i v\u00e0o \u0111\u01b0\u1ee3c H\u1ed9p th\u01b0 \u0111\u1ebfn (Inbox) thay v\u00ec Spam. C\u00e1c b\u1ed9 l\u1ecdc th\u01b0 r\u00e1c (Spam Filters) coi rDNS l\u00e0 m\u1ed9t t\u00edn hi\u1ec7u uy t\u00edn (Trust Signal) c\u1ef1c k\u1ef3 quan tr\u1ecdng.<\/p>\n<p>N\u1ebfu IP c\u1ee7a b\u1ea1n kh\u00f4ng c\u00f3 rDNS (PTR Record), \u0111i\u1ec3m uy t\u00edn (IP Reputation) c\u1ee7a b\u1ea1n s\u1ebd b\u1ecb tr\u1eeb r\u1ea5t n\u1eb7ng. Th\u1eadm ch\u00ed, nhi\u1ec1u h\u1ec7 th\u1ed1ng mail server c\u1ea5u h\u00ecnh ch\u1eb7t ch\u1ebd s\u1ebd t\u1eeb ch\u1ed1i nh\u1eadn email ngay l\u1eadp t\u1ee9c (Reject) m\u00e0 kh\u00f4ng c\u1ea7n xem n\u1ed9i dung th\u01b0 l\u00e0 g\u00ec. \u0110i\u1ec1u n\u00e0y \u0111\u1eb7c bi\u1ec7t \u0111\u00fang v\u1edbi c\u00e1c nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 email l\u1edbn nh\u01b0 Gmail, Outlook, Yahoo v\u00e0 c\u00e1c h\u1ec7 th\u1ed1ng email doanh nghi\u1ec7p b\u1ea3o m\u1eadt cao.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Reverse-DNS-va-van-de-spam-email\"><\/span>Reverse DNS v\u00e0 v\u1ea5n \u0111\u1ec1 spam email<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>M\u1ed1i quan h\u1ec7 gi\u1eefa rDNS v\u00e0 cu\u1ed9c chi\u1ebfn ch\u1ed1ng Spam l\u00e0 l\u00fd do ch\u00ednh khi\u1ebfn kh\u00e1i ni\u1ec7m <strong>Reverse DNS l\u00e0 g\u00ec<\/strong> tr\u1edf n\u00ean ph\u1ed5 bi\u1ebfn. Spam email (th\u01b0 r\u00e1c) l\u00e0 v\u1ea5n n\u1ea1n to\u00e0n c\u1ea7u, v\u00e0 rDNS l\u00e0 m\u1ed9t trong nh\u1eefng l\u00e1 ch\u1eafn \u0111\u1ea7u ti\u00ean.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Tai-sao-Spammer-thuong-khong-co-Reverse-DNS\"><\/span>T\u1ea1i sao Spammer th\u01b0\u1eddng kh\u00f4ng c\u00f3 Reverse DNS?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Nh\u1eefng k\u1ebb ph\u00e1t t\u00e1n th\u01b0 r\u00e1c th\u01b0\u1eddng s\u1eed d\u1ee5ng c\u00e1c m\u1ea1ng m\u00e1y t\u00ednh ma (botnet) \u2013 l\u00e0 h\u00e0ng tri\u1ec7u m\u00e1y t\u00ednh c\u00e1 nh\u00e2n b\u1ecb nhi\u1ec5m virus tr\u00ean kh\u1eafp th\u1ebf gi\u1edbi. C\u00e1c m\u00e1y t\u00ednh n\u00e0y th\u01b0\u1eddng s\u1eed d\u1ee5ng \u0111\u1ecba ch\u1ec9 IP \u0111\u1ed9ng (Dynamic IP) \u0111\u01b0\u1ee3c c\u1ea5p ph\u00e1t b\u1edfi nh\u00e0 m\u1ea1ng (ISP) cho h\u1ed9 gia \u0111\u00ecnh.<\/p>\n<p>\u0110\u1eb7c \u0111i\u1ec3m c\u1ee7a IP \u0111\u1ed9ng l\u00e0 c\u00e1c ISP th\u01b0\u1eddng kh\u00f4ng g\u00e1n b\u1ea3n ghi PTR c\u1ee5 th\u1ec3, ho\u1eb7c g\u00e1n c\u00e1c t\u00ean chung chung nh\u01b0 dynamic-ip-123.hcm.viettel.vn. Spammer kh\u00f4ng c\u00f3 quy\u1ec1n qu\u1ea3n tr\u1ecb \u0111\u1ec3 thay \u0111\u1ed5i b\u1ea3n ghi PTR n\u00e0y th\u00e0nh m\u1ed9t t\u00ean mi\u1ec1n uy t\u00edn.<\/p>\n<p>Do \u0111\u00f3, vi\u1ec7c ki\u1ec3m tra rDNS gi\u00fap c\u00e1c Mail Server d\u1ec5 d\u00e0ng l\u1ecdc ra c\u00e1c k\u1ebft n\u1ed1i \u0111\u1ebfn t\u1eeb c\u00e1c \u0111\u1ecba ch\u1ec9 IP h\u1ed9 gia \u0111\u00ecnh ho\u1eb7c c\u00e1c m\u00e1y t\u00ednh b\u1ecb nhi\u1ec5m virus, thay v\u00ec t\u1eeb c\u00e1c Mail Server chuy\u00ean d\u1ee5ng h\u1ee3p ph\u00e1p.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Reverse-DNS-chong-spam-nhu-the-nao\"><\/span>Reverse DNS ch\u1ed1ng spam nh\u01b0 th\u1ebf n\u00e0o?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>C\u00e1c t\u1ed5 ch\u1ee9c ch\u1ed1ng Spam qu\u1ed1c t\u1ebf (nh\u01b0 Spamhaus, Barracuda) duy tr\u00ec c\u00e1c danh s\u00e1ch \u0111en (Blacklist) d\u1ef1a tr\u00ean rDNS. N\u1ebfu m\u1ed9t d\u1ea3i IP g\u1eedi \u0111i l\u01b0\u1ee3ng l\u1edbn email nh\u01b0ng kh\u00f4ng c\u00f3 thi\u1ebft l\u1eadp PTR Record h\u1ee3p l\u1ec7, d\u1ea3i IP \u0111\u00f3 s\u1ebd b\u1ecb li\u1ec7t v\u00e0o danh s\u00e1ch \u0111en.<\/p>\n<p>Khi b\u1ea1n hi\u1ec3u r\u00f5 <strong>Reverse DNS<\/strong>, b\u1ea1n s\u1ebd th\u1ea5y n\u00f3 ho\u1ea1t \u0111\u1ed9ng nh\u01b0 m\u1ed9t &#8220;t\u1ea5m c\u0103n c\u01b0\u1edbc c\u00f4ng d\u00e2n&#8221; tr\u00ean m\u00f4i tr\u01b0\u1eddng m\u1ea1ng. K\u1ebb gian (Spammer) th\u01b0\u1eddng kh\u00f4ng d\u00e1m ho\u1eb7c kh\u00f4ng th\u1ec3 xu\u1ea5t tr\u00ecnh c\u0103n c\u01b0\u1edbc n\u00e0y. B\u1eb1ng vi\u1ec7c y\u00eau c\u1ea7u rDNS, h\u1ec7 th\u1ed1ng email c\u1ee7a b\u1ea1n \u0111\u00e3 lo\u1ea1i b\u1ecf \u0111\u01b0\u1ee3c ph\u1ea7n l\u1edbn c\u00e1c th\u01b0 r\u00e1c s\u01a1 c\u1ea5p \u0111\u1ebfn t\u1eeb c\u00e1c ngu\u1ed3n kh\u00f4ng x\u00e1c \u0111\u1ecbnh.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Tai-sao-Reverse-DNS-quan-trong-doi-voi-Email-Server\"><\/span>T\u1ea1i sao Reverse DNS quan tr\u1ecdng \u0111\u1ed1i v\u1edbi Email Server?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Ch\u00fang ta \u0111\u00e3 n\u00f3i v\u1ec1 vai tr\u00f2, nh\u01b0ng t\u1ea1i sao m\u1ee9c \u0111\u1ed9 quan tr\u1ecdng c\u1ee7a n\u00f3 l\u1ea1i \u0111\u01b0\u1ee3c \u0111\u1ea9y l\u00ean h\u00e0ng \u0111\u1ea7u trong checklist c\u1ee7a m\u1ecdi qu\u1ea3n tr\u1ecb vi\u00ean Mail Server? D\u01b0\u1edbi \u0111\u00e2y l\u00e0 nh\u1eefng l\u00fd do c\u1ee5 th\u1ec3, d\u1ef1a tr\u00ean c\u00e1c d\u1eef li\u1ec7u th\u1ef1c t\u1ebf t\u1eeb qu\u00e1 tr\u00ecnh v\u1eadn h\u00e0nh h\u1ec7 th\u1ed1ng.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Xay-dung-long-tin-voi-cac-%E2%80%9COng-lon%E2%80%9D-Trust-Score\"><\/span>X\u00e2y d\u1ef1ng l\u00f2ng tin v\u1edbi c\u00e1c &#8220;\u00d4ng l\u1edbn&#8221; (Trust Score)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Google v\u00e0 Microsoft s\u1edf h\u1eefu nh\u1eefng b\u1ed9 l\u1ecdc th\u01b0 r\u00e1c th\u00f4ng minh nh\u1ea5t th\u1ebf gi\u1edbi. H\u1ecd c\u00f4ng khai tuy\u00ean b\u1ed1 r\u1eb1ng vi\u1ec7c x\u00e1c th\u1ef1c ng\u01b0\u1eddi g\u1eedi l\u00e0 y\u1ebfu t\u1ed1 then ch\u1ed1t \u0111\u1ec3 email kh\u00f4ng b\u1ecb \u0111\u01b0a v\u00e0o Spam.<\/p>\n<p>Khi t\u00ecm hi\u1ec3u <strong>Reverse DNS l\u00e0 g\u00ec<\/strong>, b\u1ea1n c\u1ea7n bi\u1ebft r\u1eb1ng PTR Record l\u00e0 m\u1ed9t trong nh\u1eefng t\u00edn hi\u1ec7u k\u1ef9 thu\u1eadt c\u01a1 b\u1ea3n nh\u1ea5t m\u00e0 Google Postmaster Tools ki\u1ec3m tra. N\u1ebfu IP c\u1ee7a b\u1ea1n thi\u1ebfu rDNS, Google s\u1ebd \u0111\u00e1nh d\u1ea5u IP \u0111\u00f3 l\u00e0 &#8220;Bad Reputation&#8221; (Uy t\u00edn x\u1ea5u).<\/p>\n<p>M\u1ed9t khi IP \u0111\u00e3 b\u1ecb Google \u0111\u00e1nh d\u1ea5u x\u1ea5u, vi\u1ec7c kh\u00f4i ph\u1ee5c uy t\u00edn l\u00e0 c\u1ef1c k\u1ef3 kh\u00f3 kh\u0103n v\u00e0 t\u1ed1n th\u1eddi gian. C\u00f3 rDNS h\u1ee3p l\u1ec7 ngay t\u1eeb \u0111\u1ea7u gi\u1ed1ng nh\u01b0 vi\u1ec7c b\u1ea1n m\u1eb7c vest ch\u1ec9nh t\u1ec1 khi \u0111i ph\u1ecfng v\u1ea5n \u2013 n\u00f3 t\u1ea1o \u1ea5n t\u01b0\u1ee3ng t\u1ed1t v\u00e0 s\u1ef1 tin c\u1eady ngay t\u1eeb c\u00e1i nh\u00ecn \u0111\u1ea7u ti\u00ean.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Giam-thieu-nguy-co-bi-gia-mao-Spoofing\"><\/span>Gi\u1ea3m thi\u1ec3u nguy c\u01a1 b\u1ecb gi\u1ea3 m\u1ea1o (Spoofing)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u1eb7c d\u00f9 rDNS kh\u00f4ng ph\u1ea3i l\u00e0 c\u00f4ng c\u1ee5 ch\u1ed1ng gi\u1ea3 m\u1ea1o email tri\u1ec7t \u0111\u1ec3 (nh\u01b0 SPF, DKIM, DMARC), nh\u01b0ng n\u00f3 l\u00e0 l\u1edbp b\u1ea3o v\u1ec7 n\u1ec1n t\u1ea3ng. Khi m\u1ed9t m\u00e1y ch\u1ee7 nh\u1eadn th\u1ea5y IP g\u1eedi \u0111\u1ebfn c\u00f3 PTR record tr\u1ecf v\u1ec1 m\u1ed9t t\u00ean mi\u1ec1n ho\u00e0n to\u00e0n kh\u00e1c v\u1edbi t\u00ean mi\u1ec1n trong \u0111\u1ecba ch\u1ec9 email g\u1eedi \u0111i, n\u00f3 s\u1ebd k\u00edch ho\u1ea1t c\u00e1c quy t\u1eafc ki\u1ec3m tra nghi\u00eam ng\u1eb7t h\u01a1n. \u0110i\u1ec1u n\u00e0y gi\u00fap b\u1ea3o v\u1ec7 th\u01b0\u01a1ng hi\u1ec7u c\u1ee7a doanh nghi\u1ec7p kh\u1ecfi vi\u1ec7c b\u1ecb k\u1ebb x\u1ea5u l\u1ee3i d\u1ee5ng IP \u0111\u1ec3 g\u1eedi th\u01b0 l\u1eeba \u0111\u1ea3o.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"De-dang-Debug-va-khac-phuc-su-co\"><\/span>D\u1ec5 d\u00e0ng Debug v\u00e0 kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u1ed1i v\u1edbi \u0111\u1ed9i ng\u0169 k\u1ef9 thu\u1eadt t\u1ea1i <strong>InterData<\/strong>, rDNS l\u00e0 tr\u1ee3 th\u1ee7 \u0111\u1eafc l\u1ef1c khi h\u1ed7 tr\u1ee3 kh\u00e1ch h\u00e0ng. Khi kh\u00e1ch h\u00e0ng b\u00e1o c\u00e1o l\u1ed7i g\u1eedi mail, vi\u1ec7c ki\u1ec3m tra log h\u1ec7 th\u1ed1ng s\u1ebd d\u1ec5 d\u00e0ng h\u01a1n nhi\u1ec1u n\u1ebfu c\u00e1c d\u00f2ng log hi\u1ec3n th\u1ecb hostname thay v\u00ec h\u00e0ng lo\u1ea1t \u0111\u1ecba ch\u1ec9 IP v\u00f4 ngh\u0129a. \u0110i\u1ec1u n\u00e0y gi\u00fap gi\u1ea3m th\u1eddi gian ch\u1ebft (downtime) c\u1ee7a h\u1ec7 th\u1ed1ng v\u00e0 t\u0103ng t\u1ed1c \u0111\u1ed9 x\u1eed l\u00fd s\u1ef1 c\u1ed1.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cac-thanh-phan-ky-thuat-tao-nen-Reverse-DNS\"><\/span>C\u00e1c th\u00e0nh ph\u1ea7n k\u1ef9 thu\u1eadt t\u1ea1o n\u00ean Reverse DNS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>H\u1ec7 th\u1ed1ng <strong>Reverse DNS<\/strong> \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng d\u1ef1a tr\u00ean ba y\u1ebfu t\u1ed1 n\u1ec1n t\u1ea3ng: <strong>b\u1ea3n ghi PTR<\/strong>, <strong>c\u00e1c v\u00f9ng d\u1eef li\u1ec7u DNS ng\u01b0\u1ee3c (Reverse Zone)<\/strong> v\u00e0 <strong>m\u1ed9t kh\u00f4ng gian t\u00ean mi\u1ec1n c\u1ea5p cao chuy\u00ean d\u00f9ng cho h\u1ea1 t\u1ea7ng Internet<\/strong>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Ban-ghi-PTR-la-gi-trong-Reverse-DNS\"><\/span>B\u1ea3n ghi PTR l\u00e0 g\u00ec trong Reverse DNS?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Tr\u1ecdng t\u00e2m c\u1ee7a Reverse DNS ch\u00ednh l\u00e0 <strong>b\u1ea3n ghi PTR (Pointer Record)<\/strong>. \u0110\u00e2y l\u00e0 lo\u1ea1i b\u1ea3n ghi \u0111\u1ea3m nhi\u1ec7m m\u1ed9t ch\u1ee9c n\u0103ng duy nh\u1ea5t nh\u01b0ng mang t\u00ednh then ch\u1ed1t: <strong>li\u00ean k\u1ebft m\u1ed9t \u0111\u1ecba ch\u1ec9 IP v\u1edbi t\u00ean mi\u1ec1n t\u01b0\u01a1ng \u1ee9ng<\/strong>.<\/p>\n<p>V\u1ec1 b\u1ea3n ch\u1ea5t, PTR ho\u1ea1t \u0111\u1ed9ng theo chi\u1ec1u ng\u01b0\u1ee3c l\u1ea1i ho\u00e0n to\u00e0n so v\u1edbi <strong>b\u1ea3n ghi A (Address Record)<\/strong> trong DNS th\u00f4ng th\u01b0\u1eddng, n\u01a1i t\u00ean mi\u1ec1n \u0111\u01b0\u1ee3c tr\u1ecf t\u1edbi IP.<\/p>\n<p>M\u1ed9t b\u1ea3n ghi PTR th\u01b0\u1eddng \u0111\u01b0\u1ee3c khai b\u00e1o trong c\u1ea5u h\u00ecnh DNS v\u1edbi c\u00fa ph\u00e1p nh\u01b0 sau:<\/p>\n<pre><code>101.57.162.203.in-addr.arpa IN PTR mail.example.com.\r\n<\/code><\/pre>\n<p>Trong v\u00ed d\u1ee5 n\u00e0y, b\u1ea3n ghi PTR x\u00e1c \u0111\u1ecbnh r\u1eb1ng \u0111\u1ecba ch\u1ec9 IP <strong>203.162.57.101<\/strong> \u0111\u01b0\u1ee3c \u00e1nh x\u1ea1 ng\u01b0\u1ee3c v\u1ec1 t\u00ean mi\u1ec1n <strong>mail.example.com<\/strong>.<\/p>\n<figure id=\"attachment_36846\" aria-describedby=\"caption-attachment-36846\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-36846\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Thanh-phan-ky-thuat-tao-nen-Reverse-DNS.jpg\" alt=\"Th\u00e0nh ph\u1ea7n k\u1ef9 thu\u1eadt t\u1ea1o n\u00ean Reverse DNS\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Thanh-phan-ky-thuat-tao-nen-Reverse-DNS.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Thanh-phan-ky-thuat-tao-nen-Reverse-DNS-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Thanh-phan-ky-thuat-tao-nen-Reverse-DNS-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-36846\" class=\"wp-caption-text\">Th\u00e0nh ph\u1ea7n k\u1ef9 thu\u1eadt t\u1ea1o n\u00ean Reverse DNS<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"Reverse-Zone-va-khong-gian-luu-tru-DNS-nguoc\"><\/span>Reverse Zone v\u00e0 kh\u00f4ng gian l\u01b0u tr\u1eef DNS ng\u01b0\u1ee3c<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>N\u1ebfu coi b\u1ea3n ghi PTR l\u00e0 n\u1ed9i dung, th\u00ec <strong>Reverse Zone<\/strong> ch\u00ednh l\u00e0 n\u01a1i ch\u1ee9a n\u1ed9i dung \u0111\u00f3. \u0110\u00e2y l\u00e0 m\u1ed9t v\u00f9ng d\u1eef li\u1ec7u ho\u1eb7c file zone \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh ri\u00eang tr\u00ean m\u00e1y ch\u1ee7 DNS, d\u00f9ng \u0111\u1ec3 l\u01b0u tr\u1eef c\u00e1c b\u1ea3n ghi \u00e1nh x\u1ea1 t\u1eeb <strong>\u0111\u1ecba ch\u1ec9 IP sang t\u00ean mi\u1ec1n<\/strong>, t\u1ee9c c\u00e1c b\u1ea3n ghi PTR.<\/p>\n<p>Khi m\u1ed9t h\u1ec7 th\u1ed1ng g\u1eedi y\u00eau c\u1ea7u tra c\u1ee9u Reverse DNS cho m\u1ed9t IP c\u1ee5 th\u1ec3, DNS s\u1ebd truy v\u1ea5n \u0111\u1ebfn <strong>Reverse Zone<\/strong> t\u01b0\u01a1ng \u1ee9ng v\u1edbi d\u1ea3i IP \u0111\u00f3 \u0111\u1ec3 t\u00ecm b\u1ea3n ghi PTR v\u00e0 x\u00e1c \u0111\u1ecbnh hostname li\u00ean quan. Trong tr\u01b0\u1eddng h\u1ee3p <strong>Reverse Zone kh\u00f4ng t\u1ed3n t\u1ea1i<\/strong> ho\u1eb7c <strong>kh\u00f4ng c\u00f3 b\u1ea3n ghi PTR ph\u00f9 h\u1ee3p<\/strong>, qu\u00e1 tr\u00ecnh ph\u00e2n gi\u1ea3i \u0111\u1ea3o DNS s\u1ebd kh\u00f4ng th\u1ec3 th\u1ef1c hi\u1ec7n th\u00e0nh c\u00f4ng.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Khong-gian-ten-mien-cap-cao-arpa-trong-Reverse-DNS\"><\/span>Kh\u00f4ng gian t\u00ean mi\u1ec1n c\u1ea5p cao .arpa trong Reverse DNS<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>To\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng t\u00ean mi\u1ec1n ng\u01b0\u1ee3c \u0111\u01b0\u1ee3c t\u1ed5 ch\u1ee9c b\u00ean d\u01b0\u1edbi m\u1ed9t <strong>t\u00ean mi\u1ec1n c\u1ea5p cao \u0111\u1eb7c bi\u1ec7t l\u00e0 <code>.arpa<\/code><\/strong>, \u0111\u01b0\u1ee3c d\u00e0nh ri\u00eang cho c\u00e1c m\u1ee5c \u0111\u00edch h\u1ea1 t\u1ea7ng Internet.<br \/>\nTrong kh\u00f4ng gian n\u00e0y, c\u00f3 hai \u0111\u1ecbnh danh quan tr\u1ecdng t\u01b0\u01a1ng \u1ee9ng v\u1edbi hai th\u1ebf h\u1ec7 \u0111\u1ecba ch\u1ec9 IP:<\/p>\n<ul>\n<li><strong>in-addr.arpa<\/strong>: \u0110\u01b0\u1ee3c s\u1eed d\u1ee5ng cho kh\u00f4ng gian Reverse DNS c\u1ee7a <strong>IPv4<\/strong>. M\u1ecdi t\u00ean mi\u1ec1n ng\u01b0\u1ee3c \u0111\u01b0\u1ee3c t\u1ea1o t\u1eeb \u0111\u1ecba ch\u1ec9 IPv4 \u0111\u1ec1u k\u1ebft th\u00fac b\u1eb1ng <code>.in-addr.arpa<\/code>.<\/li>\n<li><strong>ip6.arpa<\/strong>: D\u00f9ng cho kh\u00f4ng gian Reverse DNS c\u1ee7a <strong>IPv6<\/strong>, ph\u1ee5c v\u1ee5 nhu c\u1ea7u m\u1edf r\u1ed9ng \u0111\u1ecba ch\u1ec9 c\u1ee7a Internet hi\u1ec7n \u0111\u1ea1i.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Co-che-uy-quyen-quan-ly-Reverse-DNS-hoat-dong-nhu-the-nao\"><\/span>C\u01a1 ch\u1ebf \u1ee7y quy\u1ec1n qu\u1ea3n l\u00fd Reverse DNS ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u00e2y l\u00e0 y\u1ebfu t\u1ed1 quy\u1ebft \u0111\u1ecbnh <strong>ai c\u00f3 quy\u1ec1n c\u1ea5u h\u00ecnh v\u00e0 qu\u1ea3n l\u00fd Reverse DNS<\/strong>.<\/p>\n<p>Quy\u1ec1n t\u1ea1o v\u00e0 ch\u1ec9nh s\u1eeda b\u1ea3n ghi Reverse DNS (PTR) <strong>kh\u00f4ng thu\u1ed9c v\u1ec1 ng\u01b0\u1eddi s\u1edf h\u1eefu t\u00ean mi\u1ec1n<\/strong>, m\u00e0 thu\u1ed9c v\u1ec1 <strong>\u0111\u01a1n v\u1ecb n\u1eafm quy\u1ec1n qu\u1ea3n l\u00fd d\u1ea3i \u0111\u1ecba ch\u1ec9 IP<\/strong>, th\u01b0\u1eddng l\u00e0 <strong>ISP ho\u1eb7c nh\u00e0 cung c\u1ea5p hosting\/VPS<\/strong>.<\/p>\n<p>Trong th\u1ef1c t\u1ebf, \u0111i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0:<\/p>\n<ul>\n<li>B\u1ea1n kh\u00f4ng th\u1ec3 t\u1ef1 thi\u1ebft l\u1eadp Reverse DNS trong trang qu\u1ea3n l\u00fd t\u00ean mi\u1ec1n.<\/li>\n<li>B\u1ea1n c\u1ea7n li\u00ean h\u1ec7 v\u00e0 g\u1eedi y\u00eau c\u1ea7u cho nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 \u0111\u1ec3 h\u1ecd t\u1ea1o ho\u1eb7c ch\u1ec9nh s\u1eeda b\u1ea3n ghi PTR cho IP \u0111\u00e3 c\u1ea5p.<\/li>\n<\/ul>\n<p>C\u01a1 ch\u1ebf \u1ee7y quy\u1ec1n n\u00e0y gi\u00fap \u0111\u1ea3m b\u1ea3o r\u1eb1ng <strong>ch\u1ec9 ch\u1ee7 s\u1edf h\u1eefu h\u1ee3p ph\u00e1p c\u1ee7a d\u1ea3i IP<\/strong> m\u1edbi c\u00f3 quy\u1ec1n g\u00e1n t\u00ean mi\u1ec1n cho \u0111\u1ecba ch\u1ec9 \u0111\u00f3, t\u1eeb \u0111\u00f3 n\u00e2ng cao m\u1ee9c \u0111\u1ed9 x\u00e1c th\u1ef1c v\u00e0 b\u1ea3o m\u1eadt tr\u00ean Internet.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Ai-la-nguoi-quan-ly-Reverse-DNS-tai-Viet-Nam\"><\/span>Ai l\u00e0 ng\u01b0\u1eddi qu\u1ea3n l\u00fd Reverse DNS t\u1ea1i Vi\u1ec7t Nam?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Vi\u1ec7c qu\u1ea3n l\u00fd <strong>t\u00ean mi\u1ec1n ng\u01b0\u1ee3c (Reverse DNS)<\/strong> t\u1ea1i Vi\u1ec7t Nam \u0111\u01b0\u1ee3c ph\u00e2n c\u1ea5p r\u00f5 r\u00e0ng theo t\u1eebng \u0111\u1ed1i t\u01b0\u1ee3ng.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Nha-cung-cap-dich-vu-ISPIXP-Don-vi-quan-ly-chinh\"><\/span>Nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 (ISP\/IXP): \u0110\u01a1n v\u1ecb qu\u1ea3n l\u00fd ch\u00ednh<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>C\u00e1c <strong>ISP v\u00e0 IXP<\/strong> nh\u01b0 FPT, Viettel, VNPT,\u2026 l\u00e0 nh\u1eefng \u0111\u01a1n v\u1ecb tr\u1ef1c ti\u1ebfp qu\u1ea3n l\u00fd b\u1ea3n ghi Reverse DNS cho c\u00e1c d\u1ea3i IP m\u00e0 h\u1ecd s\u1edf h\u1eefu. Quy\u1ec1n qu\u1ea3n l\u00fd n\u00e0y \u0111\u01b0\u1ee3c \u1ee7y quy\u1ec1n t\u1eeb c\u00e1c t\u1ed5 ch\u1ee9c c\u1ea5p cao h\u01a1n nh\u01b0 <strong>APNIC<\/strong>, v\u1edbi <strong>VNNIC (Trung t\u00e2m Internet Vi\u1ec7t Nam)<\/strong> \u0111\u00f3ng vai tr\u00f2 \u0111i\u1ec1u ph\u1ed1i \u1edf c\u1ea5p qu\u1ed1c gia.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Khach-hang-%E2%80%93-nguoi-su-dung-IP-Ben-gui-yeu-cau\"><\/span>Kh\u00e1ch h\u00e0ng \u2013 ng\u01b0\u1eddi s\u1eed d\u1ee5ng IP: B\u00ean g\u1eedi y\u00eau c\u1ea7u<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Khi b\u1ea1n thu\u00ea ho\u1eb7c s\u1eed d\u1ee5ng m\u1ed9t \u0111\u1ecba ch\u1ec9 IP t\u1eeb nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5, b\u1ea1n l\u00e0 ng\u01b0\u1eddi d\u00f9ng IP \u0111\u00f3 nh\u01b0ng <strong>kh\u00f4ng c\u00f3 quy\u1ec1n tr\u1ef1c ti\u1ebfp qu\u1ea3n l\u00fd Reverse DNS<\/strong>. \u0110\u1ec3 c\u1ea5u h\u00ecnh ho\u1eb7c thay \u0111\u1ed5i b\u1ea3n ghi PTR, b\u1ea1n c\u1ea7n li\u00ean h\u1ec7 v\u1edbi nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 v\u00e0 g\u1eedi y\u00eau c\u1ea7u \u0111\u1ec3 h\u1ecd th\u1ef1c hi\u1ec7n tr\u00ean h\u1ec7 th\u1ed1ng DNS c\u1ee7a h\u1ecd.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Truong-hop-dac-biet-Uy-quyen-lai-cho-khach-hang-lon\"><\/span>Tr\u01b0\u1eddng h\u1ee3p \u0111\u1eb7c bi\u1ec7t: \u1ee6y quy\u1ec1n l\u1ea1i cho kh\u00e1ch h\u00e0ng l\u1edbn<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Trong m\u1ed9t s\u1ed1 t\u00ecnh hu\u1ed1ng, ISP c\u00f3 th\u1ec3 <strong>\u1ee7y quy\u1ec1n l\u1ea1i quy\u1ec1n qu\u1ea3n l\u00fd Reverse DNS<\/strong> cho m\u1ed9t subnet nh\u1ecf h\u01a1n m\u00e0 kh\u00e1ch h\u00e0ng \u0111ang s\u1eed d\u1ee5ng. H\u00ecnh th\u1ee9c n\u00e0y th\u01b0\u1eddng ch\u1ec9 \u00e1p d\u1ee5ng cho <strong>doanh nghi\u1ec7p ho\u1eb7c t\u1ed5 ch\u1ee9c l\u1edbn<\/strong> c\u00f3 h\u1ea1 t\u1ea7ng m\u1ea1ng ri\u00eang v\u00e0 h\u1ec7 th\u1ed1ng DNS \u0111\u1ed9c l\u1eadp. Khi \u0111\u00f3, kh\u00e1ch h\u00e0ng c\u00f3 th\u1ec3 t\u1ef1 qu\u1ea3n l\u00fd Reverse DNS cho d\u1ea3i IP c\u1ee7a m\u00ecnh.<\/p>\n<p>T\u00f3m l\u1ea1i, <strong>ISP v\u1eabn l\u00e0 \u0111\u01a1n v\u1ecb n\u1eafm quy\u1ec1n qu\u1ea3n l\u00fd Reverse DNS<\/strong>, ng\u01b0\u1eddi d\u00f9ng cu\u1ed1i ch\u1ec9 c\u00f3 th\u1ec3 y\u00eau c\u1ea7u thay \u0111\u1ed5i. Vi\u1ec7c \u1ee7y quy\u1ec1n l\u1ea1i ch\u1ec9 x\u1ea3y ra trong nh\u1eefng tr\u01b0\u1eddng h\u1ee3p \u0111\u1eb7c bi\u1ec7t v\u1edbi kh\u00e1ch h\u00e0ng doanh nghi\u1ec7p.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Quyen-quan-ly-Reverse-DNS-va-co-che-chuyen-giao-tai-Viet-Nam\"><\/span>Quy\u1ec1n qu\u1ea3n l\u00fd Reverse DNS v\u00e0 c\u01a1 ch\u1ebf chuy\u1ec3n giao t\u1ea1i Vi\u1ec7t Nam<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>V\u1ec1 b\u1ea3n ch\u1ea5t, <strong>quy\u1ec1n qu\u1ea3n l\u00fd Reverse DNS<\/strong> thu\u1ed9c v\u1ec1 c\u00e1c nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 Internet v\u00e0 t\u1ed5 ch\u1ee9c qu\u1ea3n l\u00fd t\u00e0i nguy\u00ean Internet qu\u1ed1c gia, t\u1ea1i Vi\u1ec7t Nam l\u00e0 <strong>VNNIC<\/strong>. Nguy\u00ean nh\u00e2n l\u00e0 c\u00e1c \u0111\u01a1n v\u1ecb n\u00e0y tr\u1ef1c ti\u1ebfp s\u1edf h\u1eefu v\u00e0 ph\u00e2n ph\u1ed1i c\u00e1c d\u1ea3i \u0111\u1ecba ch\u1ec9 IP cho ng\u01b0\u1eddi d\u00f9ng cu\u1ed1i.<\/p>\n<p>Theo c\u01a1 ch\u1ebf hi\u1ec7n h\u00e0nh, <strong>VNNIC<\/strong> ch\u1ecbu tr\u00e1ch nhi\u1ec7m \u0111\u0103ng k\u00fd c\u00e1c b\u1ea3n ghi DNS ng\u01b0\u1ee3c cho v\u00f9ng \u0111\u1ecba ch\u1ec9 IP c\u1ee7a c\u00e1c ISP v\u00e0 IXP. Sau \u0111\u00f3, VNNIC th\u1ef1c hi\u1ec7n <strong>chuy\u1ec3n giao quy\u1ec1n qu\u1ea3n l\u00fd c\u00e1c kh\u1ed1i \u0111\u1ecba ch\u1ec9 Class C<\/strong> t\u1eeb m\u00e1y ch\u1ee7 DNS c\u1ee7a <strong>APNIC<\/strong> v\u1ec1 m\u00e1y ch\u1ee7 DNS c\u1ee7a c\u00e1c ISP\/IXP t\u1ea1i Vi\u1ec7t Nam \u0111\u1ec3 qu\u1ea3n l\u00fd tr\u1ef1c ti\u1ebfp.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Phan-biet-Forward-DNS-va-Reverse-DNS\"><\/span>Ph\u00e2n bi\u1ec7t Forward DNS v\u00e0 Reverse DNS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u1ec3 tr\u00e1nh nh\u1ea7m l\u1eabn trong qu\u00e1 tr\u00ecnh c\u1ea5u h\u00ecnh, ch\u00fang ta c\u1ea7n ph\u00e2n bi\u1ec7t r\u1ea1ch r\u00f2i gi\u1eefa DNS thu\u1eadn v\u00e0 DNS ng\u01b0\u1ee3c. Nhi\u1ec1u ng\u01b0\u1eddi v\u1eabn l\u1ea7m t\u01b0\u1edfng r\u1eb1ng ch\u1ec9 c\u1ea7n tr\u1ecf t\u00ean mi\u1ec1n v\u1ec1 IP l\u00e0 xong, nh\u01b0ng th\u1ef1c t\u1ebf \u0111\u00f3 m\u1edbi ch\u1ec9 l\u00e0 m\u1ed9t chi\u1ec1u c\u1ee7a con \u0111\u01b0\u1eddng.<\/p>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 b\u1ea3ng so s\u00e1nh chi ti\u1ebft gi\u00fap b\u1ea1n n\u1eafm b\u1eaft s\u1ef1 kh\u00e1c bi\u1ec7t:<\/p>\n<table style=\"width: 100%; border-collapse: collapse; font-family: Arial, sans-serif; margin: 24px 0; box-shadow: 0 8px 24px rgba(0,0,0,0.08);\">\n<thead>\n<tr style=\"background: linear-gradient(90deg, #0C40F4, #077FFA, #0497FC); color: #ffffff;\">\n<th style=\"padding: 14px; text-align: left; border: 1px solid #e6e6e6;\">\u0110\u1eb7c \u0111i\u1ec3m<\/th>\n<th style=\"padding: 14px; text-align: left; border: 1px solid #e6e6e6;\">Forward DNS (DNS Thu\u1eadn)<\/th>\n<th style=\"padding: 14px; text-align: left; border: 1px solid #e6e6e6;\">Reverse DNS (DNS Ng\u01b0\u1ee3c)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"background: #f9fbff;\">\n<td style=\"padding: 12px; border: 1px solid #e6e6e6; font-weight: 600;\">Ch\u1ee9c n\u0103ng ch\u00ednh<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">Ph\u00e2n gi\u1ea3i T\u00ean mi\u1ec1n (Domain) sang \u0111\u1ecba ch\u1ec9 IP.<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">Ph\u00e2n gi\u1ea3i \u0111\u1ecba ch\u1ec9 IP sang T\u00ean mi\u1ec1n (Hostname).<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6; font-weight: 600;\">V\u00ed d\u1ee5 minh h\u1ecda<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">mail.interdata.vn \u2794 103.xxx.xxx.xxx<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">103.xxx.xxx.xxx \u2794 mail.interdata.vn<\/td>\n<\/tr>\n<tr style=\"background: #f9fbff;\">\n<td style=\"padding: 12px; border: 1px solid #e6e6e6; font-weight: 600;\">Lo\u1ea1i b\u1ea3n ghi<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">A Record (IPv4), AAAA Record (IPv6).<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">PTR Record (Pointer Record).<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6; font-weight: 600;\">Quy\u1ec1n qu\u1ea3n tr\u1ecb<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">B\u1ea1n th\u1ef1c hi\u1ec7n t\u1ea1i n\u01a1i mua T\u00ean mi\u1ec1n (Domain Registrar).<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">B\u1ea1n y\u00eau c\u1ea7u n\u01a1i cung c\u1ea5p IP (Hosting\/ISP Provider).<\/td>\n<\/tr>\n<tr style=\"background: #f9fbff;\">\n<td style=\"padding: 12px; border: 1px solid #e6e6e6; font-weight: 600;\">V\u00f9ng l\u01b0u tr\u1eef (Zone)<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">C\u00e1c zone t\u00ean mi\u1ec1n th\u00f4ng th\u01b0\u1eddng (v\u00ed d\u1ee5: .vn, .com).<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">V\u00f9ng \u0111\u1eb7c bi\u1ec7t: in-addr.arpa (IPv4) ho\u1eb7c ip6.arpa (IPv6).<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6; font-weight: 600;\">M\u1ee9c \u0111\u1ed9 ph\u1ed5 bi\u1ebfn<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">B\u1eaft bu\u1ed9c \u0111\u1ec3 website v\u00e0 c\u00e1c d\u1ecbch v\u1ee5 Internet ho\u1ea1t \u0111\u1ed9ng.<\/td>\n<td style=\"padding: 12px; border: 1px solid #e6e6e6;\">B\u1eaft bu\u1ed9c ch\u1ee7 y\u1ebfu cho Mail Server v\u00e0 h\u1ea1 t\u1ea7ng m\u1ea1ng.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Hi\u1ec3u \u0111\u01b0\u1ee3c s\u1ef1 kh\u00e1c bi\u1ec7t n\u00e0y gi\u00fap b\u1ea1n tr\u1ea3 l\u1eddi c\u00e2u h\u1ecfi\u00a0Reverse DNS l\u00e0 g\u00ec\u00a0m\u1ed9t c\u00e1ch to\u00e0n di\u1ec7n h\u01a1n: N\u00f3 l\u00e0 chi\u1ec1u &#8220;\u0111i v\u1ec1&#8221; c\u1ee7a m\u1ed9t chuy\u1ebfn \u0111i kh\u1ee9 h\u1ed3i. N\u1ebfu Forward DNS l\u00e0 v\u00e9 \u0111i, th\u00ec Reverse DNS l\u00e0 v\u00e9 v\u1ec1. M\u1ed9t h\u1ec7 th\u1ed1ng mail ho\u00e0n ch\u1ec9nh c\u1ea7n c\u1ea3 hai chi\u1ec1u n\u00e0y ph\u1ea3i kh\u1edbp nhau (g\u1ecdi l\u00e0 Forward-Confirmed Reverse DNS &#8211; FCrDNS).<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Dieu-gi-xay-ra-neu-IP-khong-co-Reverse-DNS\"><\/span>\u0110i\u1ec1u g\u00ec x\u1ea3y ra n\u1ebfu IP kh\u00f4ng c\u00f3 Reverse DNS?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>N\u1ebfu b\u1ea1n v\u1eabn c\u00f2n b\u0103n kho\u0103n li\u1ec7u c\u00f3 n\u00ean b\u1ecf qua b\u01b0\u1edbc c\u1ea5u h\u00ecnh n\u00e0y hay kh\u00f4ng, h\u00e3y xem x\u00e9t nh\u1eefng h\u1eadu qu\u1ea3 nghi\u00eam tr\u1ecdng sau \u0111\u00e2y. Vi\u1ec7c xem nh\u1eb9 c\u00e2u h\u1ecfi <strong>Reverse DNS l\u00e0 g\u00ec<\/strong> v\u00e0 t\u1ea7m quan tr\u1ecdng c\u1ee7a n\u00f3 c\u00f3 th\u1ec3 khi\u1ebfn doanh nghi\u1ec7p tr\u1ea3 gi\u00e1 b\u1eb1ng uy t\u00edn v\u00e0 doanh thu.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Email-bi-tu-choi-thang-thung-Bounce-Back\"><\/span>Email b\u1ecb t\u1eeb ch\u1ed1i th\u1eb3ng th\u1eebng (Bounce Back)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>H\u1eadu qu\u1ea3 nh\u00e3n ti\u1ec1n nh\u1ea5t l\u00e0 email b\u1ecb tr\u1ea3 l\u1ea1i. B\u1ea1n s\u1ebd nh\u1eadn \u0111\u01b0\u1ee3c c\u00e1c th\u00f4ng b\u00e1o l\u1ed7i (NDR &#8211; Non-Delivery Report) c\u00f3 m\u00e3 nh\u01b0 550 ho\u1eb7c 554. N\u1ed9i dung l\u1ed7i th\u01b0\u1eddng r\u1ea5t r\u00f5 r\u00e0ng:<\/p>\n<ul>\n<li>&#8220;550 No PTR record for 1.2.3.4&#8221;<\/li>\n<li>&#8220;554 5.7.1 Service unavailable; Client host [1.2.3.4] blocked using rDNS&#8221;<\/li>\n<li>&#8220;Connection refused due to lack of reverse DNS&#8221;<\/li>\n<\/ul>\n<p>Khi g\u1eb7p c\u00e1c l\u1ed7i n\u00e0y, b\u1ea1n kh\u00f4ng th\u1ec3 l\u00e0m g\u00ec kh\u00e1c ngo\u00e0i vi\u1ec7c li\u00ean h\u1ec7 nh\u00e0 cung c\u1ea5p \u0111\u1ec3 c\u00e0i \u0111\u1eb7t rDNS. M\u1ecdi n\u1ed7 l\u1ef1c g\u1eedi l\u1ea1i (retry) \u0111\u1ec1u v\u00f4 \u00edch.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Email-vao-Spam-folder\"><\/span>Email v\u00e0o Spam folder<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Trong tr\u01b0\u1eddng h\u1ee3p may m\u1eafn h\u01a1n, email kh\u00f4ng b\u1ecb ch\u1eb7n nh\u01b0ng s\u1ebd b\u1ecb t\u1ed1ng th\u1eb3ng v\u00e0o m\u1ee5c Spam. \u0110\u1ed1i v\u1edbi c\u00e1c chi\u1ebfn d\u1ecbch Email Marketing, \u0111i\u1ec1u n\u00e0y \u0111\u1ed3ng ngh\u0129a v\u1edbi vi\u1ec7c ng\u00e2n s\u00e1ch qu\u1ea3ng c\u00e1o b\u1ecb \u0111\u1ed5 xu\u1ed1ng s\u00f4ng xu\u1ed1ng bi\u1ec3n. T\u1ef7 l\u1ec7 m\u1edf mail (Open rate) s\u1ebd gi\u1ea3m th\u00ea th\u1ea3m, v\u00e0 t\u00ean mi\u1ec1n c\u1ee7a b\u1ea1n c\u00f3 nguy c\u01a1 b\u1ecb ng\u01b0\u1eddi d\u00f9ng report spam, d\u1eabn \u0111\u1ebfn vi\u1ec7c t\u00ean mi\u1ec1n ch\u00ednh c\u0169ng b\u1ecb \u1ea3nh h\u01b0\u1edfng uy t\u00edn (Domain Reputation).<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Gian-doan-giao-dich-kinh-doanh\"><\/span>Gi\u00e1n \u0111o\u1ea1n giao d\u1ecbch kinh doanh<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>H\u00e3y t\u01b0\u1edfng t\u01b0\u1ee3ng b\u1ea1n \u0111ang g\u1eedi h\u1ee3p \u0111\u1ed3ng ho\u1eb7c h\u00f3a \u0111\u01a1n quan tr\u1ecdng cho \u0111\u1ed1i t\u00e1c, nh\u01b0ng email kh\u00f4ng \u0111\u1ebfn n\u01a1i do thi\u1ebfu rDNS. \u0110\u1ed1i t\u00e1c kh\u00f4ng nh\u1eadn \u0111\u01b0\u1ee3c tin, c\u00f4ng vi\u1ec7c \u0111\u00ecnh tr\u1ec7, v\u00e0 h\u00ecnh \u1ea3nh chuy\u00ean nghi\u1ec7p c\u1ee7a c\u00f4ng ty b\u1ecb \u1ea3nh h\u01b0\u1edfng nghi\u00eam tr\u1ecdng. \u0110\u00e2y l\u00e0 &#8220;chi ph\u00ed \u1ea9n&#8221; c\u1ee7a vi\u1ec7c kh\u00f4ng c\u1ea5u h\u00ecnh k\u1ef9 thu\u1eadt chu\u1ea9n ch\u1ec9.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Reverse-DNS-co-bat-buoc-khong\"><\/span>Reverse DNS c\u00f3 b\u1eaft bu\u1ed9c kh\u00f4ng?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u00e2y l\u00e0 m\u1ed9t c\u00e2u h\u1ecfi s\u1eafc s\u1ea3o. Sau khi \u0111\u00e3 hi\u1ec3u <strong>Reverse DNS l\u00e0 g\u00ec<\/strong>, nhi\u1ec1u ng\u01b0\u1eddi t\u1ef1 h\u1ecfi li\u1ec7u n\u00f3 c\u00f3 ph\u1ea3i l\u00e0 quy \u0111\u1ecbnh b\u1eaft bu\u1ed9c cho t\u1ea5t c\u1ea3 m\u1ecdi ng\u01b0\u1eddi? C\u00e2u tr\u1ea3 l\u1eddi ph\u1ee5 thu\u1ed9c v\u00e0o v\u1ecb tr\u00ed v\u00e0 m\u1ee5c \u0111\u00edch s\u1eed d\u1ee5ng IP c\u1ee7a b\u1ea1n.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Doi-voi-nguoi-dung-Internet-thong-thuong\"><\/span>\u0110\u1ed1i v\u1edbi ng\u01b0\u1eddi d\u00f9ng Internet th\u00f4ng th\u01b0\u1eddng<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>N\u1ebfu b\u1ea1n ch\u1ec9 l\u00e0 ng\u01b0\u1eddi d\u00f9ng Internet t\u1ea1i nh\u00e0, l\u01b0\u1edbt web, xem phim, ch\u01a1i game, th\u00ec <strong>Reverse DNS l\u00e0 kh\u00f4ng b\u1eaft bu\u1ed9c<\/strong>. Vi\u1ec7c IP \u0111\u1ed9ng c\u1ee7a b\u1ea1n c\u00f3 rDNS hay kh\u00f4ng, hay rDNS t\u00ean l\u00e0 g\u00ec, ho\u00e0n to\u00e0n kh\u00f4ng \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn tr\u1ea3i nghi\u1ec7m l\u01b0\u1edbt web c\u1ee7a b\u1ea1n. C\u00e1c nh\u00e0 m\u1ea1ng (ISP) s\u1ebd t\u1ef1 \u0111\u1ed9ng qu\u1ea3n l\u00fd vi\u1ec7c n\u00e0y v\u00e0 b\u1ea1n kh\u00f4ng c\u1ea7n b\u1eadn t\u00e2m.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Doi-voi-Web-Server\"><\/span>\u0110\u1ed1i v\u1edbi Web Server<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u1ed1i v\u1edbi m\u00e1y ch\u1ee7 ch\u1ec9 ch\u1ea1y website (Web Server), rDNS c\u0169ng <strong>kh\u00f4ng ho\u00e0n to\u00e0n b\u1eaft bu\u1ed9c<\/strong>. Website v\u1eabn ho\u1ea1t \u0111\u1ed9ng b\u00ecnh th\u01b0\u1eddng k\u1ec3 c\u1ea3 khi IP kh\u00f4ng c\u00f3 PTR record. Tuy nhi\u00ean, vi\u1ec7c c\u00f3 rDNS v\u1eabn \u0111\u01b0\u1ee3c khuy\u1ebfn kh\u00edch \u0111\u1ec3 t\u0103ng t\u00ednh chuy\u00ean nghi\u1ec7p v\u00e0 h\u1ed7 tr\u1ee3 c\u00e1c c\u00f4ng c\u1ee5 th\u1ed1ng k\u00ea truy c\u1eadp.<\/p>\n<figure id=\"attachment_36847\" aria-describedby=\"caption-attachment-36847\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-36847\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-co-bat-buoc-khong.jpg\" alt=\"Reverse DNS c\u00f3 b\u1eaft bu\u1ed9c kh\u00f4ng?\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-co-bat-buoc-khong.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-co-bat-buoc-khong-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Reverse-DNS-co-bat-buoc-khong-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-36847\" class=\"wp-caption-text\">Reverse DNS c\u00f3 b\u1eaft bu\u1ed9c kh\u00f4ng?<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"Doi-voi-Mail-Server-BAT-BUOC\"><\/span>\u0110\u1ed1i v\u1edbi Mail Server (B\u1eaeT BU\u1ed8C)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Ri\u00eang \u0111\u1ed1i v\u1edbi m\u00e1y ch\u1ee7 g\u1eedi email (Mail Server), c\u00e2u tr\u1ea3 l\u1eddi l\u00e0 <strong>TUY\u1ec6T \u0110\u1ed0I B\u1eaeT BU\u1ed8C<\/strong>. Nh\u01b0 \u0111\u00e3 ph\u00e2n t\u00edch \u1edf tr\u00ean, trong k\u1ef7 nguy\u00ean ch\u1ed1ng spam hi\u1ec7n \u0111\u1ea1i, kh\u00f4ng m\u1ed9t h\u1ec7 th\u1ed1ng mail uy t\u00edn n\u00e0o ch\u1ea5p nh\u1eadn giao ti\u1ebfp c\u1edfi m\u1edf v\u1edbi m\u1ed9t IP &#8220;v\u00f4 danh&#8221;.<\/p>\n<p>N\u1ebfu b\u1ea1n v\u1eadn h\u00e0nh Mail Server (d\u00f9 l\u00e0 Exchange, Zimbra, Mdaemon hay Postfix tr\u00ean VPS), vi\u1ec7c \u0111\u1ea7u ti\u00ean sau khi thu\u00ea IP l\u00e0 ph\u1ea3i y\u00eau c\u1ea7u nh\u00e0 cung c\u1ea5p c\u1ea5u h\u00ecnh Reverse DNS ngay l\u1eadp t\u1ee9c.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Khi-nao-can-su-dung-Reverse-DNS\"><\/span>Khi n\u00e0o c\u1ea7n s\u1eed d\u1ee5ng Reverse DNS?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Reverse DNS \u0111\u00f3ng vai tr\u00f2 \u0111\u1eb7c bi\u1ec7t quan tr\u1ecdng khi b\u1ea1n v\u1eadn h\u00e0nh <strong>mail server<\/strong>, qu\u1ea3n l\u00fd <strong>h\u1ea1 t\u1ea7ng cloud<\/strong>, <strong>API n\u1ed9i b\u1ed9<\/strong> ho\u1eb7c c\u00e1c h\u1ec7 th\u1ed1ng logging ph\u1ee9c t\u1ea1p. V\u1edbi nh\u1eefng d\u1ecbch v\u1ee5 y\u00eau c\u1ea7u m\u1ee9c \u0111\u1ed9 tin c\u1eady v\u00e0 x\u00e1c th\u1ef1c cao, rDNS g\u1ea7n nh\u01b0 l\u00e0 \u0111i\u1ec1u b\u1eaft bu\u1ed9c.<\/p>\n<p>Ng\u01b0\u1ee3c l\u1ea1i, \u0111\u1ed1i v\u1edbi website th\u00f4ng th\u01b0\u1eddng ho\u1eb7c c\u00e1c \u1ee9ng d\u1ee5ng kh\u00f4ng c\u1ea7n x\u00e1c th\u1ef1c IP, Reverse DNS ch\u1ee7 y\u1ebfu mang t\u00ednh h\u1ed7 tr\u1ee3. D\u00f9 kh\u00f4ng b\u1eaft bu\u1ed9c, vi\u1ec7c c\u1ea5u h\u00ecnh rDNS v\u1eabn mang l\u1ea1i l\u1ee3i \u00edch l\u00e2u d\u00e0i trong c\u00f4ng t\u00e1c qu\u1ea3n tr\u1ecb v\u00e0 v\u1eadn h\u00e0nh h\u1ec7 th\u1ed1ng.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cach-cau-hinh-Reverse-DNS-rDNS-cho-dia-chi-IP\"><\/span>C\u00e1ch c\u1ea5u h\u00ecnh Reverse DNS (rDNS) cho \u0111\u1ecba ch\u1ec9 IP<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u1ec3 thi\u1ebft l\u1eadp <strong>Reverse DNS (rDNS)<\/strong> cho m\u1ed9t \u0111\u1ecba ch\u1ec9 IP, b\u1ea1n c\u1ea7n th\u1ef1c hi\u1ec7n theo c\u00e1c b\u01b0\u1edbc c\u01a1 b\u1ea3n sau:<\/p>\n<ul>\n<li><strong>B\u01b0\u1edbc 1:<\/strong> Truy c\u1eadp v\u00e0o h\u1ec7 th\u1ed1ng qu\u1ea3n l\u00fd m\u00e1y ch\u1ee7 DNS m\u00e0 b\u1ea1n \u0111ang s\u1eed d\u1ee5ng.<\/li>\n<li><strong>B\u01b0\u1edbc 2:<\/strong> T\u00ecm \u0111\u1ebfn b\u1ea3n ghi <strong>PTR (Pointer Record)<\/strong> c\u1ee7a \u0111\u1ecba ch\u1ec9 IP c\u1ea7n c\u1ea5u h\u00ecnh Reverse DNS.<\/li>\n<li><strong>B\u01b0\u1edbc 3:<\/strong> Trong b\u1ea3n ghi PTR, nh\u1eadp t\u00ean mi\u1ec1n m\u00e0 b\u1ea1n mu\u1ed1n \u00e1nh x\u1ea1 ng\u01b0\u1ee3c v\u1edbi \u0111\u1ecba ch\u1ec9 IP \u0111\u00f3.<\/li>\n<li><strong>B\u01b0\u1edbc 4:<\/strong> L\u01b0u l\u1ea1i c\u1ea5u h\u00ecnh v\u00e0 ch\u1edd m\u1ed9t kho\u1ea3ng th\u1eddi gian \u0111\u1ec3 b\u1ea3n ghi PTR \u0111\u01b0\u1ee3c c\u1eadp nh\u1eadt v\u00e0 c\u00f3 hi\u1ec7u l\u1ef1c tr\u00ean to\u00e0n h\u1ec7 th\u1ed1ng DNS to\u00e0n c\u1ea7u.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Cac-cong-cu-kiem-tra-Reverse-DNS-Reverse-DNS-Lookup\"><\/span>C\u00e1c c\u00f4ng c\u1ee5 ki\u1ec3m tra Reverse DNS (Reverse DNS Lookup)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>C\u00e1c c\u00f4ng c\u1ee5 d\u00f9ng \u0111\u1ec3 <strong>tra c\u1ee9u Reverse DNS<\/strong> v\u1ec1 c\u01a1 b\u1ea3n ho\u1ea1t \u0111\u1ed9ng t\u01b0\u01a1ng t\u1ef1 nh\u01b0 nh\u1eefng c\u00f4ng c\u1ee5 ki\u1ec3m tra DNS th\u00f4ng th\u01b0\u1eddng. Tr\u00ean h\u1ec7 \u0111i\u1ec1u h\u00e0nh Windows, c\u00e1ch \u0111\u01a1n gi\u1ea3n nh\u1ea5t \u0111\u1ec3 ki\u1ec3m tra b\u1ea3n ghi Reverse DNS c\u1ee7a m\u1ed9t \u0111\u1ecba ch\u1ec9 IP l\u00e0 s\u1eed d\u1ee5ng l\u1ec7nh <strong><code>nslookup<\/code><\/strong>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Kiem-tra-Reverse-DNS-tren-Windows-bang-nslookup\"><\/span>Ki\u1ec3m tra Reverse DNS tr\u00ean Windows b\u1eb1ng nslookup<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>V\u00ed d\u1ee5 minh h\u1ecda tr\u00ean h\u1ec7 \u0111i\u1ec1u h\u00e0nh Windows:<\/p>\n<pre><code>Microsoft Windows XP [Version 5.1.2600]\r\n(C) Copyright 1985-2001 Microsoft Corp.\r\n\r\nC:\\Documents and Settings\\User&gt;nslookup 66.40.65.49\r\n<\/code><\/pre>\n<p>K\u1ebft qu\u1ea3 tr\u1ea3 v\u1ec1:<\/p>\n<pre><code>Address: 10.1.0.1\r\nName: www.ntchosting.com\r\nAddress: 66.40.65.49\r\n<\/code><\/pre>\n<p>Th\u00f4ng tin n\u00e0y cho bi\u1ebft \u0111\u1ecba ch\u1ec9 IP \u0111\u00e3 \u0111\u01b0\u1ee3c \u00e1nh x\u1ea1 ng\u01b0\u1ee3c v\u1ec1 t\u00ean mi\u1ec1n t\u01b0\u01a1ng \u1ee9ng th\u00f4ng qua Reverse DNS.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Kiem-tra-Reverse-DNS-tren-LinuxUnix-bang-lenh-host\"><\/span>Ki\u1ec3m tra Reverse DNS tr\u00ean Linux\/Unix b\u1eb1ng l\u1ec7nh host<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u1ed1i v\u1edbi c\u00e1c h\u1ec7 th\u1ed1ng d\u1ef1a tr\u00ean Unix ho\u1eb7c Linux, b\u1ea1n c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng l\u1ec7nh <strong><code>host<\/code><\/strong>. L\u1ec7nh n\u00e0y th\u01b0\u1eddng d\u00f9ng \u0111\u1ec3 ki\u1ec3m tra b\u1ea3n ghi A c\u1ee7a t\u00ean mi\u1ec1n, \u0111\u1ed3ng th\u1eddi c\u0169ng c\u00f3 th\u1ec3 \u00e1p d\u1ee5ng \u0111\u1ec3 x\u00e1c minh xem \u0111\u1ecba ch\u1ec9 IP c\u00f3 \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh Reverse DNS ch\u00ednh x\u00e1c hay kh\u00f4ng.<\/p>\n<p>V\u00ed d\u1ee5:<\/p>\n<pre><code>host 66.40.65.49\r\n<\/code><\/pre>\n<p>K\u1ebft qu\u1ea3 tr\u1ea3 v\u1ec1:<\/p>\n<pre><code>49.65.40.66.in-addr.arpa domain name pointer www.ntchosting.com.\r\n<\/code><\/pre>\n<h3><span class=\"ez-toc-section\" id=\"Tra-cuu-Reverse-DNS-bang-cong-cu-truc-tuyen\"><\/span>Tra c\u1ee9u Reverse DNS b\u1eb1ng c\u00f4ng c\u1ee5 tr\u1ef1c tuy\u1ebfn<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>T\u01b0\u01a1ng t\u1ef1 nh\u01b0 DNS th\u00f4ng th\u01b0\u1eddng, hi\u1ec7n nay c\u00f3 nhi\u1ec1u c\u00f4ng c\u1ee5 tr\u1ef1c tuy\u1ebfn h\u1ed7 tr\u1ee3 <strong>Reverse DNS Lookup<\/strong>. B\u1ea1n ch\u1ec9 c\u1ea7n nh\u1eadp \u0111\u1ecba ch\u1ec9 IP c\u1ea7n ki\u1ec3m tra, sau \u0111\u00f3 nh\u1ea5n n\u00fat \u201cCheck Domain\u201d \u0111\u1ec3 x\u00e1c minh xem IP \u0111\u00f3 c\u00f3 t\u1ed3n t\u1ea1i b\u1ea3n ghi ph\u00e2n gi\u1ea3i \u0111\u1ea3o DNS hay kh\u00f4ng.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cac-loi-Reverse-DNS-thuong-gap-va-huong-khac-phuc\"><\/span>C\u00e1c l\u1ed7i Reverse DNS th\u01b0\u1eddng g\u1eb7p v\u00e0 h\u01b0\u1edbng kh\u1eafc ph\u1ee5c<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Khong-ton-tai-ban-ghi-PTR\"><\/span>Kh\u00f4ng t\u1ed3n t\u1ea1i b\u1ea3n ghi PTR<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>L\u1ed7i n\u00e0y x\u1ea3y ra khi \u0111\u1ecba ch\u1ec9 IP <strong>ch\u01b0a \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh Reverse DNS<\/strong>. Tr\u01b0\u1eddng h\u1ee3p n\u00e0y th\u01b0\u1eddng g\u1eb7p v\u1edbi IP m\u1edbi c\u1ea5p, IP \u0111\u1ed9ng ho\u1eb7c IP ch\u01b0a \u0111\u01b0\u1ee3c nh\u00e0 cung c\u1ea5p k\u00edch ho\u1ea1t reverse zone.<\/p>\n<p>\u0110\u1ec3 x\u1eed l\u00fd, b\u1ea1n c\u1ea7n t\u1ea1o b\u1ea3n ghi PTR t\u01b0\u01a1ng \u1ee9ng trong v\u00f9ng reverse do <strong>ISP ho\u1eb7c nh\u00e0 cung c\u1ea5p server<\/strong> qu\u1ea3n l\u00fd. V\u1edbi m\u1ed9t s\u1ed1 \u0111\u01a1n v\u1ecb, b\u1ea1n s\u1ebd c\u1ea7n g\u1eedi ticket y\u00eau c\u1ea7u h\u1ecd th\u1ef1c hi\u1ec7n c\u1ea5u h\u00ecnh gi\u00fap.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Ban-ghi-PTR-khong-khop-voi-A-record\"><\/span>B\u1ea3n ghi PTR kh\u00f4ng kh\u1edbp v\u1edbi A record<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>PTR record v\u00e0 A record c\u1ea7n tr\u1ecf ng\u01b0\u1ee3c l\u1eabn nhau \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o t\u00ednh nh\u1ea5t qu\u00e1n. N\u1ebfu hostname trong b\u1ea3n ghi PTR kh\u00f4ng tr\u00f9ng v\u1edbi hostname trong A record, nhi\u1ec1u h\u1ec7 th\u1ed1ng s\u1ebd \u0111\u00e1nh gi\u00e1 k\u1ebft n\u1ed1i l\u00e0 kh\u00f4ng \u0111\u00e1ng tin c\u1eady.<\/p>\n<p>L\u1ed7i n\u00e0y th\u01b0\u1eddng d\u1eabn \u0111\u1ebfn vi\u1ec7c email b\u1ecb gi\u1ea3m \u0111i\u1ec3m uy t\u00edn ho\u1eb7c c\u00e1c d\u1ecbch v\u1ee5 API t\u1eeb ch\u1ed1i k\u1ebft n\u1ed1i. C\u00e1ch kh\u1eafc ph\u1ee5c l\u00e0 ki\u1ec3m tra l\u1ea1i c\u1ea3 hai b\u1ea3n ghi v\u00e0 ch\u1ec9nh s\u1eeda \u0111\u1ec3 hostname kh\u1edbp ch\u00ednh x\u00e1c theo c\u1ea3 hai chi\u1ec1u.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Dia-chi-IP-thuoc-nha-mang-khong-ho-tro-Reverse-DNS\"><\/span>\u0110\u1ecba ch\u1ec9 IP thu\u1ed9c nh\u00e0 m\u1ea1ng kh\u00f4ng h\u1ed7 tr\u1ee3 Reverse DNS<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u1ed9t s\u1ed1 ISP, \u0111\u1eb7c bi\u1ec7t l\u00e0 c\u00e1c nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 Internet gia \u0111\u00ecnh, kh\u00f4ng cho ph\u00e9p ng\u01b0\u1eddi d\u00f9ng t\u1ef1 t\u1ea1o b\u1ea3n ghi PTR do IP th\u01b0\u1eddng l\u00e0 <strong>IP \u0111\u1ed9ng<\/strong>.<\/p>\n<p>Trong tr\u01b0\u1eddng h\u1ee3p n\u00e0y, gi\u1ea3i ph\u00e1p duy nh\u1ea5t l\u00e0 chuy\u1ec3n sang s\u1eed d\u1ee5ng <strong>IP t\u0129nh<\/strong> ho\u1eb7c <strong>VPS<\/strong> c\u00f3 h\u1ea1 t\u1ea7ng h\u1ed7 tr\u1ee3 c\u1ea5u h\u00ecnh Reverse DNS. \u0110i\u1ec1u n\u00e0y \u0111\u1eb7c bi\u1ec7t c\u1ea7n thi\u1ebft n\u1ebfu b\u1ea1n mu\u1ed1n v\u1eadn h\u00e0nh mail server ho\u1eb7c c\u00e1c d\u1ecbch v\u1ee5 y\u00eau c\u1ea7u x\u00e1c th\u1ef1c IP.<\/p>\n<figure id=\"attachment_36848\" aria-describedby=\"caption-attachment-36848\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-36848\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Cac-loi-Reverse-DNS-thuong-gap.webp\" alt=\"C\u00e1c l\u1ed7i Reverse DNS th\u01b0\u1eddng g\u1eb7p\" width=\"800\" height=\"379\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Cac-loi-Reverse-DNS-thuong-gap.webp 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Cac-loi-Reverse-DNS-thuong-gap-300x142.webp 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Cac-loi-Reverse-DNS-thuong-gap-768x364.webp 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-36848\" class=\"wp-caption-text\">C\u00e1c l\u1ed7i Reverse DNS th\u01b0\u1eddng g\u1eb7p<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"Server-email-bi-danh-dau-spam-do-Reverse-DNS-sai\"><\/span>Server email b\u1ecb \u0111\u00e1nh d\u1ea5u spam do Reverse DNS sai<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u1ed9t l\u1ed7i ph\u1ed5 bi\u1ebfn kh\u00e1c l\u00e0 email b\u1ecb \u0111\u01b0a v\u00e0o spam v\u00ec Reverse DNS c\u1ee7a IP g\u1eedi kh\u00f4ng kh\u1edbp v\u1edbi hostname c\u1ee7a mail server. C\u00e1c b\u1ed9 l\u1ecdc spam hi\u1ec7n \u0111\u1ea1i xem \u0111\u00e2y l\u00e0 d\u1ea5u hi\u1ec7u r\u1ee7i ro cao.<br \/>\n\u0110\u1ec3 kh\u1eafc ph\u1ee5c, b\u1ea1n c\u1ea7n \u0111\u1ed3ng b\u1ed9 l\u1ea1i <strong>PTR record, A record v\u00e0 hostname c\u1ee7a server email<\/strong>, \u0111\u1ea3m b\u1ea3o m\u1ecdi th\u00f4ng tin x\u00e1c th\u1ef1c \u0111\u1ec1u th\u1ed1ng nh\u1ea5t tr\u01b0\u1edbc khi g\u1eedi mail ra ngo\u00e0i.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Reverse-DNS-va-nhung-luu-y-quan-trong-khi-su-dung\"><\/span>Reverse DNS v\u00e0 nh\u1eefng l\u01b0u \u00fd quan tr\u1ecdng khi s\u1eed d\u1ee5ng<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>Reverse DNS (rDNS)<\/strong> l\u00e0 m\u1ed9t th\u00e0nh ph\u1ea7n quan tr\u1ecdng trong h\u1ec7 th\u1ed1ng ph\u00e2n gi\u1ea3i t\u00ean mi\u1ec1n (DNS), cho ph\u00e9p \u00e1nh x\u1ea1 \u0111\u1ecba ch\u1ec9 IP v\u1ec1 t\u00ean mi\u1ec1n t\u01b0\u01a1ng \u1ee9ng. Vi\u1ec7c c\u1ea5u h\u00ecnh rDNS \u0111\u00fang c\u00e1ch gi\u00fap h\u1ea1n ch\u1ebf nguy c\u01a1 email b\u1ecb \u0111\u00e1nh d\u1ea5u l\u00e0 th\u01b0 r\u00e1c, \u0111\u1ed3ng th\u1eddi h\u1ed7 tr\u1ee3 t\u1ed1t h\u01a1n trong vi\u1ec7c theo d\u00f5i ngu\u1ed3n g\u1ed1c l\u01b0u l\u01b0\u1ee3ng m\u1ea1ng.<\/p>\n<p>Khi tri\u1ec3n khai rDNS, b\u1ea1n c\u1ea7n \u0111\u1ea3m b\u1ea3o r\u1eb1ng <strong>b\u1ea3n ghi PTR<\/strong> \u0111\u01b0\u1ee3c thi\u1ebft l\u1eadp ch\u00ednh x\u00e1c, \u0111\u00fang v\u1edbi \u0111\u1ecba ch\u1ec9 IP v\u00e0 t\u00ean mi\u1ec1n t\u01b0\u01a1ng \u1ee9ng. Ngo\u00e0i ra, ng\u01b0\u1eddi d\u00f9ng n\u00ean th\u01b0\u1eddng xuy\u00ean s\u1eed d\u1ee5ng c\u00e1c c\u00f4ng c\u1ee5 ki\u1ec3m tra rDNS \u0111\u1ec3 x\u00e1c nh\u1eadn r\u1eb1ng c\u1ea5u h\u00ecnh v\u1eabn \u0111ang ho\u1ea1t \u0111\u1ed9ng \u0111\u00fang nh\u01b0 mong mu\u1ed1n.<\/p>\n<p>Vi\u1ec7c c\u1eadp nh\u1eadt <strong>Reverse DNS<\/strong> c\u0169ng r\u1ea5t c\u1ea7n thi\u1ebft khi b\u1ea1n di chuy\u1ec3n m\u00e1y ch\u1ee7 ho\u1eb7c thay \u0111\u1ed5i h\u1ea1 t\u1ea7ng. N\u1ebfu kh\u00f4ng c\u1eadp nh\u1eadt k\u1ecbp th\u1eddi, h\u1ec7 th\u1ed1ng c\u00f3 th\u1ec3 g\u1eb7p v\u1ea5n \u0111\u1ec1 nh\u01b0 email b\u1ecb \u0111\u00e1nh d\u1ea5u l\u00e0 spam ho\u1eb7c kh\u00f3 x\u00e1c \u0111\u1ecbnh ngu\u1ed3n g\u1ed1c l\u01b0u l\u01b0\u1ee3ng m\u1ea1ng.<\/p>\n<p>B\u00ean c\u1ea1nh \u0111\u00f3, khi c\u00f3 s\u1ef1 thay \u0111\u1ed5i v\u1ec1 m\u00e1y ch\u1ee7, b\u1ea1n c\u0169ng n\u00ean \u0111\u1ed3ng th\u1eddi c\u1eadp nh\u1eadt l\u1ea1i <strong>\u0111\u1ecba ch\u1ec9 IP v\u00e0 th\u00f4ng tin rDNS t\u01b0\u01a1ng \u1ee9ng<\/strong> \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o h\u1ec7 th\u1ed1ng v\u1eadn h\u00e0nh \u1ed5n \u0111\u1ecbnh v\u00e0 kh\u00f4ng ph\u00e1t sinh l\u1ed7i kh\u00f4ng mong mu\u1ed1n.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Ket-luan\"><\/span>K\u1ebft lu\u1eadn<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Qua b\u00e0i vi\u1ebft n\u00e0y, hy v\u1ecdng b\u1ea1n \u0111\u00e3 c\u00f3 c\u00e1i nh\u00ecn t\u01b0\u1eddng t\u1eadn v\u00e0 s\u00e2u s\u1eafc v\u1ec1 c\u00e2u h\u1ecfi <strong>Reverse DNS l\u00e0 g\u00ec<\/strong>. Kh\u00f4ng ch\u1ec9 \u0111\u01a1n thu\u1ea7n l\u00e0 m\u1ed9t thu\u1eadt ng\u1eef k\u1ef9 thu\u1eadt kh\u00f4 khan, rDNS l\u00e0 t\u1ea5m khi\u00ean b\u1ea3o v\u1ec7 uy t\u00edn cho h\u1ec7 th\u1ed1ng email c\u1ee7a doanh nghi\u1ec7p b\u1ea1n. N\u00f3 l\u00e0 c\u1ea7u n\u1ed1i x\u00e1c th\u1ef1c gi\u00fap c\u00e1c m\u00e1y ch\u1ee7 tr\u00ean to\u00e0n c\u1ea7u &#8220;tin t\u01b0\u1edfng&#8221; v\u00e0 giao ti\u1ebfp v\u1edbi nhau an to\u00e0n h\u01a1n.<\/p>\n<p>Vi\u1ec7c b\u1ecf qua c\u1ea5u h\u00ecnh Reverse DNS gi\u1ed1ng nh\u01b0 vi\u1ec7c x\u00e2y nh\u00e0 m\u00e0 qu\u00ean l\u1eafp bi\u1ec3n s\u1ed1 \u2013 b\u01b0u t\u00e1 (Mail Server) s\u1ebd kh\u00f4ng th\u1ec3 t\u00ecm th\u1ea5y ho\u1eb7c t\u1eeb ch\u1ed1i giao h\u00e0ng v\u00ec nghi ng\u1edd \u0111\u1ecba ch\u1ec9 gi\u1ea3. \u0110\u1eebng \u0111\u1ec3 nh\u1eefng l\u1ed7i k\u1ef9 thu\u1eadt nh\u1ecf n\u00e0y c\u1ea3n tr\u1edf d\u00f2ng ch\u1ea3y th\u00f4ng tin v\u00e0 c\u01a1 h\u1ed9i kinh doanh c\u1ee7a b\u1ea1n.<\/p>\n<p>N\u1ebfu b\u1ea1n \u0111ang g\u1eb7p kh\u00f3 kh\u0103n trong vi\u1ec7c ki\u1ec3m tra, c\u1ea5u h\u00ecnh rDNS ho\u1eb7c \u0111ang \u0111au \u0111\u1ea7u v\u00ec email li\u00ean t\u1ee5c v\u00e0o Spam, \u0111\u1eebng ng\u1ea7n ng\u1ea1i li\u00ean h\u1ec7 v\u1edbi <strong>InterData<\/strong>. V\u1edbi kinh nghi\u1ec7m v\u1eadn h\u00e0nh h\u1ea1 t\u1ea7ng m\u00e1y ch\u1ee7 v\u00e0 email chuy\u00ean nghi\u1ec7p, ch\u00fang t\u00f4i lu\u00f4n s\u1eb5n s\u00e0ng h\u1ed7 tr\u1ee3 b\u1ea1n t\u1ed1i \u01b0u h\u00f3a h\u1ec7 th\u1ed1ng \u0111\u1ec3 \u0111\u1ea1t hi\u1ec7u su\u1ea5t cao nh\u1ea5t.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Khi g\u1eedi email t\u1eeb m\u1ed9t server nh\u01b0ng th\u01b0 l\u1ea1i li\u00ean t\u1ee5c r\u01a1i v\u00e0o spam, ho\u1eb7c khi c\u1ea5u h\u00ecnh VPS v\u00e0 \u0111\u01b0\u1ee3c y\u00eau c\u1ea7u thi\u1ebft l\u1eadp PTR record, nhi\u1ec1u ng\u01b0\u1eddi b\u1eaft \u0111\u1ea7u b\u1eaft g\u1eb7p thu\u1eadt ng\u1eef &#8220;Reverse DNS&#8221; v\u00e0 th\u1eafc m\u1eafc: Reverse DNS l\u00e0 g\u00ec v\u00e0 v\u00ec sao n\u00f3 l\u1ea1i quan tr\u1ecdng \u0111\u1ebfn v\u1eady? Tr\u00ean th\u1ef1c<\/p>\n","protected":false},"author":11,"featured_media":36850,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[58],"tags":[],"class_list":["post-36841","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-server"],"_links":{"self":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/36841","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\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/comments?post=36841"}],"version-history":[{"count":5,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/36841\/revisions"}],"predecessor-version":[{"id":36852,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/36841\/revisions\/36852"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media\/36850"}],"wp:attachment":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media?parent=36841"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/categories?post=36841"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/tags?post=36841"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}