{"id":15730,"date":"2021-12-31T03:55:00","date_gmt":"2021-12-30T20:55:00","guid":{"rendered":"https:\/\/blog.tinohost.com\/?p=1078"},"modified":"2026-10-28T11:40:18","modified_gmt":"2026-10-28T04:40:18","slug":"ptr-record-la-gi","status":"publish","type":"post","link":"https:\/\/tino.vn\/blog\/ptr-record-la-gi\/","title":{"rendered":"PTR record l\u00e0 g\u00ec? Reverse DNS v\u00e0 c\u00e1ch ki\u1ec3m tra b\u1ea3n ghi PTR"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\"><strong>PTR record (Pointer record, b\u1ea3n ghi con tr\u1ecf) l\u00e0 b\u1ea3n ghi DNS d\u00f9ng \u0111\u1ec3 tra ng\u01b0\u1ee3c: h\u1ecfi m\u1ed9t \u0111\u1ecba ch\u1ec9 IP v\u00e0 nh\u1eadn v\u1ec1 t\u00ean m\u00e1y ch\u1ee7 g\u1eafn v\u1edbi IP \u0111\u00f3, ng\u01b0\u1ee3c v\u1edbi b\u1ea3n ghi A tr\u1ea3 IP cho m\u1ed9t t\u00ean.<\/strong> Vi\u1ec7c tra n\u00e0y g\u1ecdi l\u00e0 reverse DNS (rDNS) v\u00e0 quan tr\u1ecdng nh\u1ea5t v\u1edbi m\u00e1y ch\u1ee7 g\u1eedi email.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">PTR l\u00e0 m\u1ed9t lo\u1ea1i b\u1ea3n ghi c\u1ee7a <a href=\"https:\/\/tino.vn\/blog\/dns-la-gi\/\">DNS<\/a>, nh\u01b0ng kh\u00f4ng n\u1eb1m trong zone c\u1ee7a <a href=\"https:\/\/tino.vn\/blog\/ten-mien-la-gi\/\">t\u00ean mi\u1ec1n<\/a> m\u00e0 n\u1eb1m trong zone ng\u01b0\u1ee3c c\u1ee7a d\u1ea3i IP. Ph\u1ea7n d\u01b0\u1edbi gi\u1ea3i th\u00edch t\u00ean tra ng\u01b0\u1ee3c \u0111\u01b0\u1ee3c vi\u1ebft th\u1ebf n\u00e0o, ai \u0111\u01b0\u1ee3c t\u1ea1o PTR, v\u00ec sao email c\u1ea7n PTR v\u00e0 c\u00e1ch t\u1ef1 ki\u1ec3m tra.<\/p>\n\n\n\n<h2 id=\"PTR_record_l\u00e0_g\u00ec?\">PTR record l\u00e0 g\u00ec?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">PTR record l\u00e0 b\u1ea3n ghi \u00e1nh x\u1ea1 m\u1ed9t t\u00ean \u0111\u1eb7c bi\u1ec7t trong c\u00e2y in-addr.arpa (IPv4) ho\u1eb7c ip6.arpa (IPv6) sang m\u1ed9t t\u00ean m\u00e1y ch\u1ee7, \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a trong <a href=\"https:\/\/www.rfc-editor.org\/rfc\/rfc1035\" target=\"_blank\" rel=\"noopener nofollow\">RFC 1035<\/a> v\u00e0 <a href=\"https:\/\/www.rfc-editor.org\/rfc\/rfc3596\" target=\"_blank\" rel=\"noopener nofollow\">RFC 3596<\/a>. Nh\u1edd c\u00e2y t\u00ean ng\u01b0\u1ee3c n\u00e0y, DNS d\u00f9ng \u0111\u00fang c\u01a1 ch\u1ebf tra t\u00ean th\u00f4ng th\u01b0\u1eddng \u0111\u1ec3 t\u00ecm t\u00ean c\u1ee7a m\u1ed9t IP.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">PTR v\u00e0 b\u1ea3n ghi A l\u00e0 hai b\u1ea3n ghi \u0111\u1ed9c l\u1eadp, do hai b\u00ean kh\u00e1c nhau qu\u1ea3n l\u00fd. B\u1ea3n ghi A c\u1ee7a m\u1ed9t t\u00ean tr\u1ecf t\u1edbi m\u1ed9t IP kh\u00f4ng t\u1ef1 t\u1ea1o ra PTR cho IP \u0111\u00f3; ng\u01b0\u1ee3c l\u1ea1i, PTR c\u1ee7a m\u1ed9t IP c\u00f3 th\u1ec3 tr\u1ecf t\u1edbi m\u1ed9t t\u00ean ho\u00e0n to\u00e0n kh\u00e1c n\u1ebfu kh\u00f4ng ai c\u1ea5u h\u00ecnh cho kh\u1edbp.<\/p>\n\n\n\n<h2 id=\"T\u00ean_mi\u1ec1n_ng\u01b0\u1ee3c_in-addr.arpa_\u0111\u01b0\u1ee3c_vi\u1ebft_th\u1ebf_n\u00e0o?\">T\u00ean mi\u1ec1n ng\u01b0\u1ee3c in-addr.arpa \u0111\u01b0\u1ee3c vi\u1ebft th\u1ebf n\u00e0o?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">T\u00ean tra ng\u01b0\u1ee3c c\u1ee7a \u0111\u1ecba ch\u1ec9 IPv4 \u0111\u01b0\u1ee3c t\u1ea1o b\u1eb1ng c\u00e1ch \u0111\u1ea3o th\u1ee9 t\u1ef1 b\u1ed1n nh\u00f3m s\u1ed1 r\u1ed3i th\u00eam \u0111u\u00f4i .in-addr.arpa, v\u00ec DNS \u0111\u1ecdc t\u00ean t\u1eeb ph\u1ea3i sang tr\u00e1i c\u00f2n \u0111\u1ecba ch\u1ec9 IP th\u00ec ph\u1ea7n m\u1ea1ng n\u1eb1m b\u00ean tr\u00e1i. V\u00ed d\u1ee5 198.51.100.7 th\u00e0nh 7.100.51.198.in-addr.arpa.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"1400\" height=\"750\" src=\"https:\/\/tino.vn\/blog\/wp-content\/uploads\/2026\/10\/ptr-record-la-gi-tra-nguoc.webp\" alt=\"S\u01a1 \u0111\u1ed3 tra thu\u1eadn v\u00e0 tra ng\u01b0\u1ee3c: mail.tenban.vn qua b\u1ea3n ghi A ra 203.0.113.25; 203.0.113.25 \u0111\u1ea3o s\u1ed1 th\u00e0nh 25.113.0.203.in-addr.arpa, qua b\u1ea3n ghi PTR ra mail.tenban.vn.; ch\u1ee7 t\u00ean mi\u1ec1n s\u1eeda A, b\u00ean gi\u1eef d\u1ea3i IP s\u1eeda PTR, hai chi\u1ec1u n\u00ean kh\u1edbp\" class=\"wp-image-132652\" title=\"\" srcset=\"https:\/\/tino.vn\/blog\/wp-content\/uploads\/2026\/10\/ptr-record-la-gi-tra-nguoc.webp 1400w, https:\/\/tino.vn\/blog\/wp-content\/uploads\/2026\/10\/ptr-record-la-gi-tra-nguoc-300x161.webp 300w, https:\/\/tino.vn\/blog\/wp-content\/uploads\/2026\/10\/ptr-record-la-gi-tra-nguoc-1024x549.webp 1024w, https:\/\/tino.vn\/blog\/wp-content\/uploads\/2026\/10\/ptr-record-la-gi-tra-nguoc-768x411.webp 768w\" sizes=\"(max-width: 1400px) 100vw, 1400px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>.arpa<\/strong> l\u00e0 \u0111u\u00f4i d\u00e0nh cho h\u1ea1 t\u1ea7ng Internet, ch\u1ee9a c\u1ea3 hai c\u00e2y t\u00ean ng\u01b0\u1ee3c.<\/li>\n\n\n<li><strong>in-addr.arpa<\/strong> d\u00f9ng cho IPv4: m\u1ed7i nh\u00f3m s\u1ed1 c\u1ee7a IP l\u00e0 m\u1ed9t nh\u00e3n.<\/li>\n\n\n<li><strong>ip6.arpa<\/strong> d\u00f9ng cho IPv6: \u0111\u1ecba ch\u1ec9 \u0111\u01b0\u1ee3c vi\u1ebft \u0111\u1ee7 32 ch\u1eef s\u1ed1 hexa, \u0111\u1ea3o ng\u01b0\u1ee3c t\u1eebng ch\u1eef s\u1ed1 (m\u1ed7i ch\u1eef s\u1ed1 4 bit l\u00e0 m\u1ed9t nh\u00e3n) r\u1ed3i th\u00eam .ip6.arpa.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">C\u1ea5u tr\u00fac \u0111\u1ecba ch\u1ec9 \u0111\u01b0\u1ee3c gi\u1ea3i th\u00edch th\u00eam \u1edf b\u00e0i <a href=\"https:\/\/tino.vn\/blog\/dia-chi-ipv4-co-cau-truc-nhu-the-nao\/\">\u0111\u1ecba ch\u1ec9 IPv4 c\u00f3 c\u1ea5u tr\u00fac th\u1ebf n\u00e0o<\/a> v\u00e0 <a href=\"https:\/\/tino.vn\/blog\/ipv6-address-la-gi\/\">IPv6 l\u00e0 g\u00ec<\/a>.<\/p>\n\n\n\n<h2 id=\"PTR_record_d\u00f9ng_\u0111\u1ec3_l\u00e0m_g\u00ec?\">PTR record d\u00f9ng \u0111\u1ec3 l\u00e0m g\u00ec?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">PTR record gi\u00fap h\u1ec7 th\u1ed1ng nh\u1eadn bi\u1ebft m\u1ed9t IP thu\u1ed9c v\u1ec1 m\u00e1y ch\u1ee7 n\u00e0o, n\u00ean \u0111\u01b0\u1ee3c d\u00f9ng nhi\u1ec1u nh\u1ea5t \u0111\u1ec3 ki\u1ec3m tra m\u00e1y ch\u1ee7 g\u1eedi email. Ngo\u00e0i ra, PTR l\u00e0m nh\u1eadt k\u00fd m\u00e1y ch\u1ee7, l\u1ec7nh traceroute v\u00e0 c\u00f4ng c\u1ee5 gi\u00e1m s\u00e1t d\u1ec5 \u0111\u1ecdc h\u01a1n v\u00ec hi\u1ec7n t\u00ean thay cho d\u00e3y s\u1ed1.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>G\u1eedi email:<\/strong> m\u00e1y ch\u1ee7 nh\u1eadn th\u01b0 tra PTR c\u1ee7a IP g\u1eedi \u0111\u1ebfn, r\u1ed3i tra ng\u01b0\u1ee3c b\u1ea3n ghi A c\u1ee7a t\u00ean \u0111\u00f3 xem c\u00f3 v\u1ec1 \u0111\u00fang IP kh\u00f4ng. <a href=\"https:\/\/support.google.com\/a\/answer\/81126?hl=vi\" target=\"_blank\" rel=\"noopener nofollow\">H\u01b0\u1edbng d\u1eabn cho ng\u01b0\u1eddi g\u1eedi c\u1ee7a Google<\/a> y\u00eau c\u1ea7u m\u1ecdi ng\u01b0\u1eddi g\u1eedi t\u1edbi Gmail c\u00f3 b\u1ea3n ghi DNS thu\u1eadn v\u00e0 ng\u01b0\u1ee3c h\u1ee3p l\u1ec7, t\u1ee9c c\u00f3 PTR.<\/li>\n\n\n<li><strong>Ch\u1ed1ng th\u01b0 r\u00e1c:<\/strong> IP kh\u00f4ng c\u00f3 PTR, ho\u1eb7c PTR mang t\u00ean chung chung c\u1ee7a nh\u00e0 m\u1ea1ng, th\u01b0\u1eddng b\u1ecb b\u1ed9 l\u1ecdc ch\u1ea5m \u0111i\u1ec3m x\u1ea5u h\u01a1n.<\/li>\n\n\n<li><strong>Nh\u1eadt k\u00fd v\u00e0 gi\u00e1m s\u00e1t:<\/strong> log m\u00e1y ch\u1ee7, t\u01b0\u1eddng l\u1eeda, traceroute hi\u1ec3n th\u1ecb t\u00ean m\u00e1y thay v\u00ec IP, d\u1ec5 bi\u1ebft k\u1ebft n\u1ed1i \u0111\u1ebfn t\u1eeb \u0111\u00e2u.<\/li>\n\n\n<li><strong>Quy \u01b0\u1edbc v\u1eadn h\u00e0nh:<\/strong> <a href=\"https:\/\/www.rfc-editor.org\/rfc\/rfc1912\" target=\"_blank\" rel=\"noopener nofollow\">RFC 1912<\/a> khuy\u00ean m\u1ed7i IP n\u00ean c\u00f3 PTR kh\u1edbp, v\u00e0 PTR ph\u1ea3i tr\u1ecf t\u1edbi t\u00ean c\u00f3 b\u1ea3n ghi A th\u1eadt, kh\u00f4ng tr\u1ecf v\u00e0o t\u00ean ki\u1ec3u CNAME.<\/li>\n<\/ul>\n\n\n\n<h2 id=\"Ai_t\u1ea1o_v\u00e0_s\u1eeda_\u0111\u01b0\u1ee3c_b\u1ea3n_ghi_PTR?\">Ai t\u1ea1o v\u00e0 s\u1eeda \u0111\u01b0\u1ee3c b\u1ea3n ghi PTR?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">B\u1ea3n ghi PTR do b\u00ean gi\u1eef d\u1ea3i IP t\u1ea1o, th\u01b0\u1eddng l\u00e0 nh\u00e0 cung c\u1ea5p VPS, m\u00e1y ch\u1ee7 ho\u1eb7c nh\u00e0 m\u1ea1ng, kh\u00f4ng ph\u1ea3i n\u01a1i mua t\u00ean mi\u1ec1n. B\u1ea1n kh\u00f4ng th\u00eam \u0111\u01b0\u1ee3c PTR trong tr\u00ecnh qu\u1ea3n l\u00fd DNS c\u1ee7a t\u00ean mi\u1ec1n; h\u00e3y d\u00f9ng m\u1ee5c Reverse DNS c\u1ee7a trang qu\u1ea3n l\u00fd VPS ho\u1eb7c g\u1eedi y\u00eau c\u1ea7u cho nh\u00e0 cung c\u1ea5p.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Tr\u01b0\u1edbc khi xin PTR, t\u1ea1o b\u1ea3n ghi A cho t\u00ean m\u00e1y (v\u00ed d\u1ee5 mail.tenban.vn \u2192 IP c\u1ee7a VPS) \u0111\u1ec3 hai chi\u1ec1u kh\u1edbp nhau.<\/li>\n\n\n<li>M\u1ed7i IP ch\u1ec9 n\u00ean c\u00f3 m\u1ed9t PTR. M\u1ed9t m\u00e1y ch\u1ee7 g\u1eedi mail cho nhi\u1ec1u t\u00ean mi\u1ec1n v\u1eabn d\u00f9ng m\u1ed9t t\u00ean m\u00e1y chung, m\u1ed7i t\u00ean mi\u1ec1n khai SPF cho ph\u00e9p IP \u0111\u00f3.<\/li>\n\n\n<li>D\u00f9ng hosting chia s\u1ebb ho\u1eb7c d\u1ecbch v\u1ee5 email c\u00f3 s\u1eb5n th\u00ec nh\u00e0 cung c\u1ea5p \u0111\u00e3 lo PTR cho m\u00e1y ch\u1ee7 g\u1eedi; b\u1ea1n ch\u1ec9 c\u1ea5u h\u00ecnh b\u1ea3n ghi c\u1ee7a t\u00ean mi\u1ec1n. Xem th\u00eam <a href=\"https:\/\/tino.vn\/blog\/mail-server-la-gi\/\">mail server l\u00e0 g\u00ec<\/a>.<\/li>\n<\/ul>\n\n\n\n<h2 id=\"C\u00e1ch_ki\u1ec3m_tra_PTR_record\">C\u00e1ch ki\u1ec3m tra PTR record<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Ki\u1ec3m tra PTR b\u1eb1ng l\u1ec7nh nslookup tr\u00ean Windows, dig -x tr\u00ean Linux, macOS, ho\u1eb7c c\u00f4ng c\u1ee5 web; ch\u1ec9 c\u1ea7n nh\u1eadp \u0111\u1ecba ch\u1ec9 IP. K\u1ebft qu\u1ea3 \u0111\u00fang l\u00e0 t\u00ean m\u00e1y ch\u1ee7 b\u1ea1n mong \u0111\u1ee3i; n\u1ebfu tr\u1ea3 v\u1ec1 t\u00ean chung c\u1ee7a nh\u00e0 m\u1ea1ng ho\u1eb7c l\u1ed7i NXDOMAIN th\u00ec IP ch\u01b0a c\u00f3 PTR ri\u00eang.<\/p>\n\n\n\n<h3 id=\"Tr\u00ean_Windows\">Tr\u00ean Windows<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">M\u1edf Command Prompt (g\u00f5 <code>cmd<\/code> \u1edf \u00f4 t\u00ecm ki\u1ebfm c\u1ee7a Start), r\u1ed3i ch\u1ea1y l\u1ec7nh d\u01b0\u1edbi, thay IP b\u1eb1ng IP c\u1ea7n ki\u1ec3m. \u0110\u1ec3 bi\u1ebft IP c\u1ee7a m\u00e1y ch\u1ee7, xem b\u00e0i <a href=\"https:\/\/tino.vn\/blog\/kiem-tra-ip-website-online\/\">ki\u1ec3m tra IP website<\/a>.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>nslookup 8.8.8.8<\/code><\/pre>\n\n\n\n<h3 id=\"Tr\u00ean_Linux_v\u00e0_macOS\">Tr\u00ean Linux v\u00e0 macOS<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">M\u1edf Terminal (macOS: Launchpad \u2192 Terminal; nhi\u1ec1u b\u1ea3n Linux: Ctrl + Alt + T) v\u00e0 d\u00f9ng l\u1ec7nh dig v\u1edbi tu\u1ef3 ch\u1ecdn tra ng\u01b0\u1ee3c:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>dig -x 8.8.8.8 +short<\/code><\/pre>\n\n\n\n<h3 id=\"B\u1eb1ng_c\u00f4ng_c\u1ee5_web\">B\u1eb1ng c\u00f4ng c\u1ee5 web<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Nh\u1eadp IP v\u00e0o <a href=\"https:\/\/toolbox.googleapps.com\/apps\/dig\/\" target=\"_blank\" rel=\"noopener nofollow\">Google Admin Toolbox Dig<\/a> v\u00e0 ch\u1ecdn PTR, ho\u1eb7c d\u00f9ng <a href=\"https:\/\/mxtoolbox.com\/ReverseLookup.aspx\" target=\"_blank\" rel=\"noopener nofollow\">MxToolbox Reverse Lookup<\/a>. V\u00ed d\u1ee5 tra IP 8.8.8.8 c\u1ee7a Google Public DNS tr\u1ea3 v\u1ec1 t\u00ean dns.google.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"1200\" height=\"457\" src=\"https:\/\/tino.vn\/blog\/wp-content\/uploads\/2026\/10\/ptr-record-la-gi-tra-ptr-8-8-8-8.webp\" alt=\"\u1ea2nh ch\u1ee5p Google Admin Toolbox Dig ng\u00e0y 27\/10\/2026 tra b\u1ea3n ghi PTR c\u1ee7a IP 8.8.8.8: k\u1ebft qu\u1ea3 TARGET dns.google.; khoanh \u0111\u1ecf dns.google.\" class=\"wp-image-132653\" title=\"\" srcset=\"https:\/\/tino.vn\/blog\/wp-content\/uploads\/2026\/10\/ptr-record-la-gi-tra-ptr-8-8-8-8.webp 1200w, https:\/\/tino.vn\/blog\/wp-content\/uploads\/2026\/10\/ptr-record-la-gi-tra-ptr-8-8-8-8-300x114.webp 300w, https:\/\/tino.vn\/blog\/wp-content\/uploads\/2026\/10\/ptr-record-la-gi-tra-ptr-8-8-8-8-1024x390.webp 1024w, https:\/\/tino.vn\/blog\/wp-content\/uploads\/2026\/10\/ptr-record-la-gi-tra-ptr-8-8-8-8-768x292.webp 768w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><figcaption class=\"wp-element-caption\">\u1ea2nh ch\u1ee5p c\u00f4ng c\u1ee5 Google Admin Toolbox Dig (toolbox.googleapps.com) ng\u00e0y 27\/10\/2026.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Sau khi nh\u00e0 cung c\u1ea5p c\u1eadp nh\u1eadt PTR, k\u1ebft qu\u1ea3 m\u1edbi hi\u1ec7n khi resolver h\u1ebft cache b\u1ea3n ghi c\u0169 theo TTL; th\u1eed l\u1ea1i v\u1edbi resolver kh\u00e1c n\u1ebfu v\u1eabn th\u1ea5y gi\u00e1 tr\u1ecb c\u0169.<\/p>\n\n\n\n<h2 id=\"PTR_record_kh\u00e1c_b\u1ea3n_ghi_MX_th\u1ebf_n\u00e0o?\">PTR record kh\u00e1c b\u1ea3n ghi MX th\u1ebf n\u00e0o?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">B\u1ea3n ghi MX n\u1eb1m trong zone c\u1ee7a t\u00ean mi\u1ec1n v\u00e0 cho bi\u1ebft email g\u1eedi t\u1edbi t\u00ean mi\u1ec1n th\u00ec giao cho m\u00e1y ch\u1ee7 n\u00e0o; PTR n\u1eb1m trong zone ng\u01b0\u1ee3c c\u1ee7a d\u1ea3i IP v\u00e0 cho bi\u1ebft m\u1ed9t IP mang t\u00ean g\u00ec. M\u00e1y ch\u1ee7 nh\u1eadn mail c\u1ee7a b\u1ea1n c\u1ea7n MX \u0111\u00fang; m\u00e1y ch\u1ee7 g\u1eedi mail c\u1ee7a b\u1ea1n c\u1ea7n PTR \u0111\u00fang.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th><\/th><th>B\u1ea3n ghi MX<\/th><th>B\u1ea3n ghi PTR<\/th><\/tr><\/thead><tbody><tr><td>N\u1eb1m \u1edf<\/td><td>Zone c\u1ee7a t\u00ean mi\u1ec1n (tenban.vn)<\/td><td>Zone ng\u01b0\u1ee3c c\u1ee7a d\u1ea3i IP (\u2026in-addr.arpa)<\/td><\/tr><tr><td>Ai s\u1eeda<\/td><td>Ch\u1ee7 t\u00ean mi\u1ec1n<\/td><td>B\u00ean gi\u1eef d\u1ea3i IP<\/td><\/tr><tr><td>Ph\u1ee5c v\u1ee5<\/td><td>Nh\u1eadn email<\/td><td>G\u1eedi email, nh\u1eadt k\u00fd, gi\u00e1m s\u00e1t<\/td><\/tr><tr><td>V\u00ed d\u1ee5<\/td><td>tenban.vn MX 10 mx.tenban.vn.<\/td><td>7.100.51.198.in-addr.arpa PTR mail.tenban.vn.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">B\u1ed9 b\u1ea3n ghi email \u0111\u1ea7y \u0111\u1ee7 (MX, SPF, DKIM, DMARC) \u0111\u01b0\u1ee3c h\u01b0\u1edbng d\u1eabn \u1edf b\u00e0i <a href=\"https:\/\/tino.vn\/blog\/cau-hinh-email-ten-mien-rieng-tren-cloudflare\/\">c\u1ea5u h\u00ecnh email t\u00ean mi\u1ec1n ri\u00eang tr\u00ean Cloudflare<\/a>; khi g\u1eb7p l\u1ed7i kh\u00f4ng nh\u1eadn \u0111\u01b0\u1ee3c th\u01b0, xem <a href=\"https:\/\/tino.vn\/blog\/sua-loi-email-ten-mien-rieng-khong-nhan-mail\/\">s\u1eeda l\u1ed7i email t\u00ean mi\u1ec1n ri\u00eang kh\u00f4ng nh\u1eadn mail<\/a>.<\/p>\n\n\n\n<h2 id=\"Khi_n\u00e0o_kh\u00f4ng_c\u1ea7n_quan_t\u00e2m_t\u1edbi_PTR?\">Khi n\u00e0o kh\u00f4ng c\u1ea7n quan t\u00e2m t\u1edbi PTR?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">B\u1ea1n kh\u00f4ng c\u1ea7n t\u1ef1 c\u1ea5u h\u00ecnh PTR n\u1ebfu m\u00e1y ch\u1ee7 kh\u00f4ng g\u1eedi email tr\u1ef1c ti\u1ebfp, v\u00ed d\u1ee5 VPS ch\u1ec9 ch\u1ea1y website v\u00e0 g\u1eedi th\u01b0 qua d\u1ecbch v\u1ee5 SMTP b\u00ean ngo\u00e0i, ho\u1eb7c khi d\u00f9ng hosting, email doanh nghi\u1ec7p c\u00f3 s\u1eb5n. PTR c\u0169ng kh\u00f4ng \u1ea3nh h\u01b0\u1edfng t\u1edbi vi\u1ec7c ng\u01b0\u1eddi kh\u00e1c truy c\u1eadp website hay t\u1edbi th\u1ee9 h\u1ea1ng t\u00ecm ki\u1ebfm.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u1ea7n t\u00ean mi\u1ec1n cho website? <a href=\"https:\/\/tino.vn\/ten-mien\">\u0110\u0103ng k\u00fd t\u00ean mi\u1ec1n t\u1ea1i Tino<\/a>: ki\u1ec3m tra t\u00ean mi\u1ec1n c\u00f2n tr\u1ed1ng, \u0111\u0103ng k\u00fd .vn v\u00e0 qu\u1ed1c t\u1ebf, qu\u1ea3n l\u00fd DNS trong m\u1ed9t t\u00e0i kho\u1ea3n. Xem gi\u00e1 tr\u00ean trang s\u1ea3n ph\u1ea9m.<\/p>\n\n\n\n<h2 id=\"C\u00e2u_h\u1ecfi_th\u01b0\u1eddng_g\u1eb7p\">C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p<\/h2>\n\n\n\t\t<section\t\thelp class=\"sc_fs_faq sc_card    \"\n\t\t\t\t>\n\t\t\t\t<h2 id=\"Thi\u1ebfu_PTR_th\u00ec_email_c\u00f3_b\u1ecb_v\u00e0o_spam_kh\u00f4ng?\">Thi\u1ebfu PTR th\u00ec email c\u00f3 b\u1ecb v\u00e0o spam kh\u00f4ng?<\/h2>\t\t\t\t<div>\n\t\t\t\t\t\t<div class=\"sc_fs_faq__content\">\n\t\t\t\t\n\n<p class=\"wp-block-paragraph\">C\u00f3 th\u1ec3. PTR ch\u1ec9 l\u00e0 m\u1ed9t trong nhi\u1ec1u t\u00edn hi\u1ec7u, nh\u01b0ng nhi\u1ec1u m\u00e1y ch\u1ee7 nh\u1eadn th\u01b0, g\u1ed3m c\u1ea3 Gmail, coi IP kh\u00f4ng c\u00f3 PTR h\u1ee3p l\u1ec7 l\u00e0 d\u1ea5u hi\u1ec7u x\u1ea5u v\u00e0 c\u00f3 th\u1ec3 t\u1eeb ch\u1ed1i ho\u1eb7c \u0111\u01b0a th\u01b0 v\u00e0o spam. C\u1ea7n th\u00eam SPF, DKIM, DMARC \u0111\u00fang.<\/p>\n\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section\t\thelp class=\"sc_fs_faq sc_card    \"\n\t\t\t\t>\n\t\t\t\t<h2 id=\"M\u1ed9t_IP_c\u00f3_th\u1ec3_c\u00f3_nhi\u1ec1u_b\u1ea3n_ghi_PTR_kh\u00f4ng?\">M\u1ed9t IP c\u00f3 th\u1ec3 c\u00f3 nhi\u1ec1u b\u1ea3n ghi PTR kh\u00f4ng?<\/h2>\t\t\t\t<div>\n\t\t\t\t\t\t<div class=\"sc_fs_faq__content\">\n\t\t\t\t\n\n<p class=\"wp-block-paragraph\">V\u1ec1 k\u1ef9 thu\u1eadt th\u00ec c\u00f3, nh\u01b0ng kh\u00f4ng n\u00ean. Nhi\u1ec1u ph\u1ea7n m\u1ec1m ch\u1ec9 \u0111\u1ecdc k\u1ebft qu\u1ea3 \u0111\u1ea7u ti\u00ean, k\u1ebft qu\u1ea3 l\u1ea1i c\u00f3 th\u1ec3 \u0111\u1ed5i th\u1ee9 t\u1ef1. M\u1ed7i IP n\u00ean c\u00f3 \u0111\u00fang m\u1ed9t PTR tr\u1ecf t\u1edbi m\u1ed9t t\u00ean c\u00f3 b\u1ea3n ghi A v\u1ec1 l\u1ea1i IP \u0111\u00f3.<\/p>\n\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section\t\thelp class=\"sc_fs_faq sc_card    \"\n\t\t\t\t>\n\t\t\t\t<h2 id=\"PTR_record_m\u1ea5t_bao_l\u00e2u_\u0111\u1ec3_c\u00f3_hi\u1ec7u_l\u1ef1c?\">PTR record m\u1ea5t bao l\u00e2u \u0111\u1ec3 c\u00f3 hi\u1ec7u l\u1ef1c?<\/h2>\t\t\t\t<div>\n\t\t\t\t\t\t<div class=\"sc_fs_faq__content\">\n\t\t\t\t\n\n<p class=\"wp-block-paragraph\">Sau khi b\u00ean gi\u1eef d\u1ea3i IP c\u1eadp nh\u1eadt, PTR m\u1edbi c\u00f3 hi\u1ec7u l\u1ef1c khi resolver h\u1ebft cache b\u1ea3n ghi c\u0169, t\u1ee9c tu\u1ef3 TTL m\u00e0 nh\u00e0 cung c\u1ea5p \u0111\u1eb7t. Th\u1eddi gian x\u1eed l\u00fd y\u00eau c\u1ea7u th\u00ec tu\u1ef3 t\u1eebng nh\u00e0 cung c\u1ea5p.<\/p>\n\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t<\/section>\n\t\t\n<script type=\"application\/ld+json\">\n\t{\n\t\t\"@context\": \"https:\/\/schema.org\",\n\t\t\"@type\": \"FAQPage\",\n\t\t\"mainEntity\": [\n\t\t\t\t\t{\n\t\t\t\t\"@type\": \"Question\",\n\t\t\t\t\"name\": \"Thi\u1ebfu PTR th\u00ec email c\u00f3 b\u1ecb v\u00e0o spam kh\u00f4ng?\",\n\t\t\t\t\"acceptedAnswer\": {\n\t\t\t\t\t\"@type\": \"Answer\",\n\t\t\t\t\t\"text\": \"<p>C\u00f3 th\u1ec3. PTR ch\u1ec9 l\u00e0 m\u1ed9t trong nhi\u1ec1u t\u00edn hi\u1ec7u, nh\u01b0ng nhi\u1ec1u m\u00e1y ch\u1ee7 nh\u1eadn th\u01b0, g\u1ed3m c\u1ea3 Gmail, coi IP kh\u00f4ng c\u00f3 PTR h\u1ee3p l\u1ec7 l\u00e0 d\u1ea5u hi\u1ec7u x\u1ea5u v\u00e0 c\u00f3 th\u1ec3 t\u1eeb ch\u1ed1i ho\u1eb7c \u0111\u01b0a th\u01b0 v\u00e0o spam. C\u1ea7n th\u00eam SPF, DKIM, DMARC \u0111\u00fang.<\/p>\"\n\t\t\t\t\t\t\t\t\t}\n\t\t\t}\n\t\t\t,\t\t\t\t{\n\t\t\t\t\"@type\": \"Question\",\n\t\t\t\t\"name\": \"M\u1ed9t IP c\u00f3 th\u1ec3 c\u00f3 nhi\u1ec1u b\u1ea3n ghi PTR kh\u00f4ng?\",\n\t\t\t\t\"acceptedAnswer\": {\n\t\t\t\t\t\"@type\": \"Answer\",\n\t\t\t\t\t\"text\": \"<p>V\u1ec1 k\u1ef9 thu\u1eadt th\u00ec c\u00f3, nh\u01b0ng kh\u00f4ng n\u00ean. Nhi\u1ec1u ph\u1ea7n m\u1ec1m ch\u1ec9 \u0111\u1ecdc k\u1ebft qu\u1ea3 \u0111\u1ea7u ti\u00ean, k\u1ebft qu\u1ea3 l\u1ea1i c\u00f3 th\u1ec3 \u0111\u1ed5i th\u1ee9 t\u1ef1. M\u1ed7i IP n\u00ean c\u00f3 \u0111\u00fang m\u1ed9t PTR tr\u1ecf t\u1edbi m\u1ed9t t\u00ean c\u00f3 b\u1ea3n ghi A v\u1ec1 l\u1ea1i IP \u0111\u00f3.<\/p>\"\n\t\t\t\t\t\t\t\t\t}\n\t\t\t}\n\t\t\t,\t\t\t\t{\n\t\t\t\t\"@type\": \"Question\",\n\t\t\t\t\"name\": \"PTR record m\u1ea5t bao l\u00e2u \u0111\u1ec3 c\u00f3 hi\u1ec7u l\u1ef1c?\",\n\t\t\t\t\"acceptedAnswer\": {\n\t\t\t\t\t\"@type\": \"Answer\",\n\t\t\t\t\t\"text\": \"<p>Sau khi b\u00ean gi\u1eef d\u1ea3i IP c\u1eadp nh\u1eadt, PTR m\u1edbi c\u00f3 hi\u1ec7u l\u1ef1c khi resolver h\u1ebft cache b\u1ea3n ghi c\u0169, t\u1ee9c tu\u1ef3 TTL m\u00e0 nh\u00e0 cung c\u1ea5p \u0111\u1eb7t. Th\u1eddi gian x\u1eed l\u00fd y\u00eau c\u1ea7u th\u00ec tu\u1ef3 t\u1eebng nh\u00e0 cung c\u1ea5p.<\/p>\"\n\t\t\t\t\t\t\t\t\t}\n\t\t\t}\n\t\t\t\t\t\t]\n\t}\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>PTR record (Pointer record, b\u1ea3n ghi con tr\u1ecf) l\u00e0 b\u1ea3n ghi DNS d\u00f9ng \u0111\u1ec3 tra ng\u01b0\u1ee3c: h\u1ecfi m\u1ed9t \u0111\u1ecba ch\u1ec9 IP v\u00e0 nh\u1eadn v\u1ec1 t\u00ean m\u00e1y ch\u1ee7 g\u1eafn v\u1edbi IP \u0111\u00f3, ng\u01b0\u1ee3c v\u1edbi b\u1ea3n ghi A tr\u1ea3 IP cho m\u1ed9t t\u00ean. Vi\u1ec7c tra n\u00e0y g\u1ecdi l\u00e0 reverse DNS (rDNS) v\u00e0 quan tr\u1ecdng nh\u1ea5t v\u1edbi m\u00e1y [&hellip;]<\/p>\n","protected":false},"author":19,"featured_media":132561,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7729],"tags":[6364],"class_list":["post-15730","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dns","tag-kien-thuc-ten-mien"],"_links":{"self":[{"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/posts\/15730","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/users\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/comments?post=15730"}],"version-history":[{"count":2,"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/posts\/15730\/revisions"}],"predecessor-version":[{"id":132742,"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/posts\/15730\/revisions\/132742"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/media\/132561"}],"wp:attachment":[{"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/media?parent=15730"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/categories?post=15730"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tino.vn\/blog\/wp-json\/wp\/v2\/tags?post=15730"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}