{"id":476883,"date":"2023-08-09T09:05:02","date_gmt":"2023-08-09T09:05:02","guid":{"rendered":""},"modified":"2023-09-05T11:13:37","modified_gmt":"2023-09-05T11:13:37","slug":"dns-cache","status":"publish","type":"wiki","link":"https:\/\/oneproxy.pro\/vn\/wiki\/dns-cache\/","title":{"rendered":"B\u1ed9 \u0111\u1ec7m DNS"},"content":{"rendered":"<p>B\u1ed9 \u0111\u1ec7m DNS, vi\u1ebft t\u1eaft c\u1ee7a b\u1ed9 \u0111\u1ec7m H\u1ec7 th\u1ed1ng t\u00ean mi\u1ec1n, l\u00e0 m\u1ed9t th\u00e0nh ph\u1ea7n quan tr\u1ecdng c\u1ee7a c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng Internet. N\u00f3 \u0111\u00f3ng vai tr\u00f2 quan tr\u1ecdng trong vi\u1ec7c \u0111\u1ea9y nhanh qu\u00e1 tr\u00ecnh d\u1ecbch t\u00ean mi\u1ec1n th\u00e0nh \u0111\u1ecba ch\u1ec9 IP, gi\u00fap vi\u1ec7c duy\u1ec7t web hi\u1ec7u qu\u1ea3 v\u00e0 li\u1ec1n m\u1ea1ch h\u01a1n. B\u1ed9 \u0111\u1ec7m DNS l\u01b0u tr\u1eef c\u00e1c b\u1ea3n ghi t\u00ean mi\u1ec1n \u0111\u00e3 \u0111\u01b0\u1ee3c ph\u00e2n gi\u1ea3i tr\u01b0\u1edbc \u0111\u00f3, cho ph\u00e9p truy xu\u1ea5t nhanh ch\u00f3ng v\u00e0 gi\u1ea3m nhu c\u1ea7u truy v\u1ea5n DNS l\u1eb7p l\u1ea1i t\u1edbi c\u00e1c m\u00e1y ch\u1ee7 c\u00f3 th\u1ea9m quy\u1ec1n.<\/p>\n<h2>L\u1ecbch s\u1eed v\u1ec1 ngu\u1ed3n g\u1ed1c c\u1ee7a b\u1ed9 \u0111\u1ec7m DNS v\u00e0 l\u1ea7n \u0111\u1ea7u ti\u00ean \u0111\u1ec1 c\u1eadp \u0111\u1ebfn n\u00f3<\/h2>\n<p>Kh\u00e1i ni\u1ec7m b\u1ed9 \u0111\u1ec7m DNS \u0111\u01b0\u1ee3c gi\u1edbi thi\u1ec7u v\u00e0o n\u0103m 1983 khi Paul Mockapetris v\u00e0 Jon Postel ph\u00e1t tri\u1ec3n H\u1ec7 th\u1ed1ng t\u00ean mi\u1ec1n. DNS \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf \u0111\u1ec3 qu\u1ea3n l\u00fd vi\u1ec7c \u00e1nh x\u1ea1 t\u00ean mi\u1ec1n t\u1edbi \u0111\u1ecba ch\u1ec9 IP v\u00e0 ng\u01b0\u1ee3c l\u1ea1i, t\u1ea1o \u0111i\u1ec1u ki\u1ec7n giao ti\u1ebfp gi\u1eefa c\u00e1c m\u00e1y t\u00ednh tr\u00ean internet. \u0110\u1ec3 n\u00e2ng cao hi\u1ec7u qu\u1ea3, b\u1ed9 nh\u1edb \u0111\u1ec7m DNS \u0111\u01b0\u1ee3c tri\u1ec3n khai nh\u01b0 m\u1ed9t k\u1ef9 thu\u1eadt nh\u1eb1m gi\u1ea3m th\u1eddi gian ph\u1ea3n h\u1ed3i truy v\u1ea5n v\u00e0 t\u1ea3i m\u1ea1ng.<\/p>\n<h2>Th\u00f4ng tin chi ti\u1ebft v\u1ec1 DNS cache: M\u1edf r\u1ed9ng ch\u1ee7 \u0111\u1ec1 DNS cache<\/h2>\n<p>B\u1ed9 \u0111\u1ec7m DNS ho\u1ea1t \u0111\u1ed9ng nh\u01b0 m\u1ed9t v\u1ecb tr\u00ed l\u01b0u tr\u1eef t\u1ea1m th\u1eddi \u0111\u1ec3 l\u01b0u tr\u1eef k\u1ebft qu\u1ea3 tra c\u1ee9u DNS tr\u01b0\u1edbc \u0111\u00f3. Khi ng\u01b0\u1eddi d\u00f9ng c\u1ed1 g\u1eafng truy c\u1eadp m\u1ed9t trang web, tr\u01b0\u1edbc ti\u00ean thi\u1ebft b\u1ecb c\u1ee7a h\u1ecd s\u1ebd ki\u1ec3m tra b\u1ed9 \u0111\u1ec7m DNS c\u1ee5c b\u1ed9 \u0111\u1ec3 t\u00ecm \u0111\u1ecba ch\u1ec9 IP t\u01b0\u01a1ng \u1ee9ng. N\u1ebfu th\u00f4ng tin b\u1eaft bu\u1ed9c \u0111\u01b0\u1ee3c t\u00ecm th\u1ea5y trong b\u1ed9 \u0111\u1ec7m, h\u1ec7 th\u1ed1ng c\u00f3 th\u1ec3 ph\u00e2n gi\u1ea3i t\u00ean mi\u1ec1n m\u00e0 kh\u00f4ng c\u1ea7n ph\u1ea3i li\u00ean h\u1ec7 v\u1edbi c\u00e1c m\u00e1y ch\u1ee7 DNS c\u00f3 th\u1ea9m quy\u1ec1n, gi\u00fap gi\u1ea3m \u0111\u00e1ng k\u1ec3 th\u1eddi gian c\u1ea7n thi\u1ebft cho qu\u00e1 tr\u00ecnh ph\u00e2n gi\u1ea3i.<\/p>\n<p>Qu\u00e1 tr\u00ecnh l\u01b0u tr\u1eef DNS c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 nh\u01b0 sau:<\/p>\n<ol>\n<li>Thi\u1ebft b\u1ecb c\u1ee7a ng\u01b0\u1eddi d\u00f9ng g\u1eedi truy v\u1ea5n DNS \u0111\u1ebfn tr\u00ecnh ph\u00e2n gi\u1ea3i c\u1ee5c b\u1ed9 (th\u01b0\u1eddng l\u00e0 m\u00e1y ch\u1ee7 DNS ISP c\u1ee7a ng\u01b0\u1eddi d\u00f9ng ho\u1eb7c m\u00e1y ch\u1ee7 DNS c\u00f4ng c\u1ed9ng nh\u01b0 Google DNS).<\/li>\n<li>Tr\u00ecnh ph\u00e2n gi\u1ea3i ki\u1ec3m tra b\u1ed9 \u0111\u1ec7m c\u1ee5c b\u1ed9 c\u1ee7a n\u00f3 \u0111\u1ec3 xem li\u1ec7u n\u00f3 c\u00f3 b\u1ea3n ghi cho mi\u1ec1n \u0111\u01b0\u1ee3c y\u00eau c\u1ea7u hay kh\u00f4ng.<\/li>\n<li>N\u1ebfu t\u00ecm th\u1ea5y b\u1ea3n ghi, tr\u00ecnh ph\u00e2n gi\u1ea3i s\u1ebd tr\u1ea3 v\u1ec1 \u0111\u1ecba ch\u1ec9 IP cho thi\u1ebft b\u1ecb c\u1ee7a ng\u01b0\u1eddi d\u00f9ng.<\/li>\n<li>N\u1ebfu kh\u00f4ng t\u00ecm th\u1ea5y b\u1ea3n ghi, tr\u00ecnh ph\u00e2n gi\u1ea3i s\u1ebd li\u00ean h\u1ec7 v\u1edbi c\u00e1c m\u00e1y ch\u1ee7 DNS c\u00f3 th\u1ea9m quy\u1ec1n \u0111\u1ec3 l\u1ea5y \u0111\u1ecba ch\u1ec9 IP, sau \u0111\u00f3 l\u01b0u n\u00f3 v\u00e0o b\u1ed9 \u0111\u1ec7m \u0111\u1ec3 s\u1eed d\u1ee5ng trong t\u01b0\u01a1ng lai.<\/li>\n<\/ol>\n<p>B\u1ed9 \u0111\u1ec7m DNS th\u01b0\u1eddng c\u00f3 tu\u1ed5i th\u1ecd gi\u1edbi h\u1ea1n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 Th\u1eddi gian t\u1ed3n t\u1ea1i (TTL). Gi\u00e1 tr\u1ecb TTL \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ecbnh trong b\u1ea3n ghi DNS v\u00e0 x\u00e1c \u0111\u1ecbnh th\u00f4ng tin c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c l\u01b0u gi\u1eef trong b\u1ed9 \u0111\u1ec7m trong bao l\u00e2u tr\u01b0\u1edbc khi h\u1ebft h\u1ea1n. Khi TTL h\u1ebft h\u1ea1n, tr\u00ecnh ph\u00e2n gi\u1ea3i s\u1ebd x\u00f3a b\u1ea3n ghi \u0111\u00e3 h\u1ebft h\u1ea1n kh\u1ecfi b\u1ed9 \u0111\u1ec7m c\u1ee7a n\u00f3.<\/p>\n<h2>C\u1ea5u tr\u00fac b\u00ean trong c\u1ee7a b\u1ed9 \u0111\u1ec7m DNS: C\u00e1ch ho\u1ea1t \u0111\u1ed9ng c\u1ee7a b\u1ed9 \u0111\u1ec7m DNS<\/h2>\n<p>B\u1ed9 \u0111\u1ec7m DNS ho\u1ea1t \u0111\u1ed9ng nh\u01b0 m\u1ed9t h\u1ec7 th\u1ed1ng c\u01a1 s\u1edf d\u1eef li\u1ec7u ph\u00e2n t\u00e1n, trong \u0111\u00f3 m\u1ed7i tr\u00ecnh ph\u00e2n gi\u1ea3i DNS duy tr\u00ec b\u1ed9 \u0111\u1ec7m c\u1ee7a n\u00f3. Khi tr\u00ecnh ph\u00e2n gi\u1ea3i nh\u1eadn \u0111\u01b0\u1ee3c ph\u1ea3n h\u1ed3i DNS t\u1eeb m\u00e1y ch\u1ee7 c\u00f3 th\u1ea9m quy\u1ec1n, n\u00f3 s\u1ebd l\u01b0u tr\u1eef th\u00f4ng tin c\u1ee5c b\u1ed9 trong kho\u1ea3ng th\u1eddi gian TTL \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh tr\u01b0\u1edbc. Qu\u00e1 tr\u00ecnh tra c\u1ee9u b\u1ed9 \u0111\u1ec7m bao g\u1ed3m vi\u1ec7c t\u00ecm ki\u1ebfm b\u1ed9 \u0111\u1ec7m c\u1ee5c b\u1ed9 tr\u01b0\u1edbc khi g\u1eedi truy v\u1ea5n \u0111\u1ebfn c\u00e1c m\u00e1y ch\u1ee7 c\u00f3 th\u1ea9m quy\u1ec1n.<\/p>\n<p>C\u1ea5u tr\u00fac b\u00ean trong c\u1ee7a b\u1ed9 \u0111\u1ec7m DNS bao g\u1ed3m:<\/p>\n<ol>\n<li>\n<p><strong>B\u1ea3n ghi b\u1ed9 \u0111\u1ec7m<\/strong>: M\u1ed7i b\u1ea3n ghi b\u1ed9 \u0111\u1ec7m ch\u1ee9a t\u00ean mi\u1ec1n, \u0111\u1ecba ch\u1ec9 IP t\u01b0\u01a1ng \u1ee9ng, TTL v\u00e0 si\u00eau d\u1eef li\u1ec7u kh\u00e1c. Khi truy v\u1ea5n DNS \u0111\u01b0\u1ee3c tr\u1ea3 l\u1eddi, tr\u00ecnh ph\u00e2n gi\u1ea3i s\u1ebd t\u1ea1o ho\u1eb7c c\u1eadp nh\u1eadt b\u1ea3n ghi b\u1ed9 \u0111\u1ec7m.<\/p>\n<\/li>\n<li>\n<p><strong>Qu\u1ea3n l\u00fd TTL<\/strong>: Gi\u00e1 tr\u1ecb TTL ch\u1ec9 \u0111\u1ecbnh kho\u1ea3ng th\u1eddi gian m\u1ed9t b\u1ea3n ghi c\u00f3 hi\u1ec7u l\u1ef1c trong b\u1ed9 \u0111\u1ec7m. Sau khi TTL h\u1ebft h\u1ea1n, b\u1ed9 \u0111\u1ec7m s\u1ebd x\u00f3a b\u1ea3n ghi \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o \u0111\u1ed9 ph\u00e2n gi\u1ea3i DNS m\u1edbi.<\/p>\n<\/li>\n<li>\n<p><strong>H\u1ebft h\u1ea1n b\u1ed9 nh\u1edb<\/strong>: B\u1ed9 nh\u1edb \u0111\u1ec7m c\u1ea7n \u0111\u01b0\u1ee3c ki\u1ec3m tra th\u01b0\u1eddng xuy\u00ean \u0111\u1ec3 ph\u00e1t hi\u1ec7n c\u00e1c b\u1ea3n ghi \u0111\u00e3 h\u1ebft h\u1ea1n \u0111\u1ec3 duy tr\u00ec d\u1eef li\u1ec7u ch\u00ednh x\u00e1c. C\u00e1c b\u1ea3n ghi l\u1ed7i th\u1eddi ph\u1ea3i \u0111\u01b0\u1ee3c x\u00f3a kh\u1ecfi b\u1ed9 \u0111\u1ec7m \u0111\u1ec3 ng\u0103n vi\u1ec7c cung c\u1ea5p \u0111\u1ecba ch\u1ec9 IP kh\u00f4ng ch\u00ednh x\u00e1c.<\/p>\n<\/li>\n<\/ol>\n<h2>Ph\u00e2n t\u00edch c\u00e1c t\u00ednh n\u0103ng ch\u00ednh c\u1ee7a b\u1ed9 \u0111\u1ec7m DNS<\/h2>\n<p>B\u1ed9 \u0111\u1ec7m DNS cung c\u1ea5p m\u1ed9t s\u1ed1 t\u00ednh n\u0103ng ch\u00ednh gi\u00fap n\u00e2ng cao hi\u1ec7u qu\u1ea3 v\u00e0 \u0111\u1ed9 tin c\u1eady c\u1ee7a qu\u00e1 tr\u00ecnh ph\u00e2n gi\u1ea3i DNS:<\/p>\n<ol>\n<li>\n<p><strong>Th\u1eddi gian ph\u1ea3n h\u1ed3i nhanh h\u01a1n<\/strong>: B\u1eb1ng c\u00e1ch l\u01b0u tr\u1eef c\u00e1c truy v\u1ea5n DNS \u0111\u00e3 gi\u1ea3i quy\u1ebft tr\u01b0\u1edbc \u0111\u00f3, c\u00e1c y\u00eau c\u1ea7u ti\u1ebfp theo cho c\u00f9ng m\u1ed9t mi\u1ec1n c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c tr\u1ea3 l\u1eddi nhanh ch\u00f3ng t\u1eeb b\u1ed9 \u0111\u1ec7m c\u1ee5c b\u1ed9, gi\u1ea3m \u0111\u1ed9 tr\u1ec5 v\u00e0 c\u1ea3i thi\u1ec7n tr\u1ea3i nghi\u1ec7m ng\u01b0\u1eddi d\u00f9ng.<\/p>\n<\/li>\n<li>\n<p><strong>Gi\u1ea3m t\u1ea3i m\u1ea1ng<\/strong>: B\u1ed9 nh\u1edb \u0111\u1ec7m DNS gi\u1ea3m s\u1ed1 l\u01b0\u1ee3ng truy v\u1ea5n \u0111\u01b0\u1ee3c g\u1eedi \u0111\u1ebfn c\u00e1c m\u00e1y ch\u1ee7 DNS c\u00f3 th\u1ea9m quy\u1ec1n, gi\u00fap ph\u00e2n ph\u1ed1i t\u1ea3i truy v\u1ea5n DNS v\u00e0 c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t m\u1ea1ng t\u1ed5ng th\u1ec3.<\/p>\n<\/li>\n<li>\n<p><strong>C\u1ea3i thi\u1ec7n kh\u1ea3 n\u0103ng ph\u1ee5c h\u1ed3i<\/strong>: N\u1ebfu c\u00e1c m\u00e1y ch\u1ee7 DNS c\u00f3 th\u1ea9m quy\u1ec1n g\u1eb7p ph\u1ea3i th\u1eddi gian ng\u1eebng ho\u1ea1t \u0111\u1ed9ng ho\u1eb7c kh\u00f4ng th\u1ec3 truy c\u1eadp \u0111\u01b0\u1ee3c, c\u00e1c b\u1ea3n ghi DNS \u0111\u01b0\u1ee3c l\u01b0u trong b\u1ed9 nh\u1edb \u0111\u1ec7m v\u1eabn c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 ph\u00e2n gi\u1ea3i t\u00ean mi\u1ec1n, \u0111\u1ea3m b\u1ea3o kh\u1ea3 n\u0103ng truy c\u1eadp li\u00ean t\u1ee5c v\u00e0o c\u00e1c trang web.<\/p>\n<\/li>\n<\/ol>\n<h2>C\u00e1c lo\u1ea1i b\u1ed9 \u0111\u1ec7m DNS<\/h2>\n<p>C\u00f3 hai lo\u1ea1i b\u1ed9 \u0111\u1ec7m DNS ch\u00ednh:<\/p>\n<ol>\n<li>\n<p><strong>B\u1ed9 \u0111\u1ec7m DNS ph\u00eda m\u00e1y kh\u00e1ch<\/strong>: B\u1ed9 \u0111\u1ec7m n\u00e0y t\u1ed3n t\u1ea1i tr\u00ean c\u00e1c thi\u1ebft b\u1ecb ng\u01b0\u1eddi d\u00f9ng c\u00e1 nh\u00e2n (v\u00ed d\u1ee5: m\u00e1y t\u00ednh, \u0111i\u1ec7n tho\u1ea1i th\u00f4ng minh, b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn). N\u00f3 l\u01b0u tr\u1eef b\u1ea3n ghi DNS cho c\u00e1c mi\u1ec1n \u0111\u01b0\u1ee3c ng\u01b0\u1eddi d\u00f9ng truy c\u1eadp, cho ph\u00e9p c\u00e1c l\u1ea7n truy c\u1eadp ti\u1ebfp theo v\u00e0o c\u00f9ng m\u1ed9t mi\u1ec1n \u0111\u01b0\u1ee3c gi\u1ea3i quy\u1ebft nhanh h\u01a1n.<\/p>\n<\/li>\n<li>\n<p><strong>B\u1ed9 nh\u1edb \u0111\u1ec7m DNS ph\u00eda b\u1ed9 ph\u00e2n gi\u1ea3i<\/strong>: C\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 B\u1ed9 \u0111\u1ec7m DNS \u0111\u1ec7 quy, b\u1ed9 \u0111\u1ec7m n\u00e0y \u0111\u01b0\u1ee3c qu\u1ea3n l\u00fd b\u1edfi c\u00e1c b\u1ed9 ph\u00e2n gi\u1ea3i DNS (v\u00ed d\u1ee5: m\u00e1y ch\u1ee7 DNS c\u1ee7a ISP, m\u00e1y ch\u1ee7 DNS c\u00f4ng c\u1ed9ng). N\u00f3 l\u01b0u tr\u1eef c\u00e1c b\u1ea3n ghi DNS \u0111\u01b0\u1ee3c l\u1ea5y t\u1eeb c\u00e1c m\u00e1y ch\u1ee7 c\u00f3 th\u1ea9m quy\u1ec1n v\u00e0 ph\u1ee5c v\u1ee5 nhi\u1ec1u ng\u01b0\u1eddi d\u00f9ng, gi\u1ea3m l\u01b0u l\u01b0\u1ee3ng truy v\u1ea5n DNS t\u1ed5ng th\u1ec3.<\/p>\n<\/li>\n<\/ol>\n<p>H\u00e3y t\u00f3m t\u1eaft c\u00e1c lo\u1ea1i b\u1ed9 \u0111\u1ec7m DNS trong b\u1ea3ng:<\/p>\n<table>\n<thead>\n<tr>\n<th>Ki\u1ec3u<\/th>\n<th>V\u1ecb tr\u00ed<\/th>\n<th>S\u1ef1 qu\u1ea3n l\u00fd<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>B\u1ed9 \u0111\u1ec7m DNS ph\u00eda m\u00e1y kh\u00e1ch<\/td>\n<td>Thi\u1ebft b\u1ecb ng\u01b0\u1eddi d\u00f9ng<\/td>\n<td>T\u1ef1 \u0111\u1ed9ng l\u01b0u v\u00e0o b\u1ed9 nh\u1edb \u0111\u1ec7m c\u1ee7a h\u1ec7 \u0111i\u1ec1u h\u00e0nh<\/td>\n<\/tr>\n<tr>\n<td>B\u1ed9 nh\u1edb \u0111\u1ec7m DNS ph\u00eda b\u1ed9 ph\u00e2n gi\u1ea3i<\/td>\n<td>B\u1ed9 ph\u00e2n gi\u1ea3i DNS (m\u00e1y ch\u1ee7)<\/td>\n<td>T\u1ef1 \u0111\u1ed9ng l\u01b0u v\u00e0o b\u1ed9 nh\u1edb \u0111\u1ec7m b\u1eb1ng ph\u1ea7n m\u1ec1m ph\u00e2n gi\u1ea3i DNS<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>C\u00e1c c\u00e1ch s\u1eed d\u1ee5ng b\u1ed9 \u0111\u1ec7m DNS, c\u00e1c s\u1ef1 c\u1ed1 v\u00e0 gi\u1ea3i ph\u00e1p li\u00ean quan \u0111\u1ebfn vi\u1ec7c s\u1eed d\u1ee5ng<\/h2>\n<h3>C\u00e1c c\u00e1ch s\u1eed d\u1ee5ng b\u1ed9 \u0111\u1ec7m DNS:<\/h3>\n<ol>\n<li>\n<p><strong>Duy\u1ec7t nhanh h\u01a1n<\/strong>: B\u1eb1ng c\u00e1ch b\u1eadt b\u1ed9 \u0111\u1ec7m DNS tr\u00ean thi\u1ebft b\u1ecb kh\u00e1ch ho\u1eb7c s\u1eed d\u1ee5ng tr\u00ecnh ph\u00e2n gi\u1ea3i DNS c\u00f3 b\u1ed9 \u0111\u1ec7m hi\u1ec7u qu\u1ea3, ng\u01b0\u1eddi d\u00f9ng c\u00f3 th\u1ec3 tr\u1ea3i nghi\u1ec7m duy\u1ec7t web nhanh h\u01a1n.<\/p>\n<\/li>\n<li>\n<p><strong>T\u1ed1i \u01b0u h\u00f3a m\u1ea1ng<\/strong>: B\u1ed9 \u0111\u1ec7m DNS gi\u1ea3m kh\u1ed1i l\u01b0\u1ee3ng truy v\u1ea5n DNS, t\u1ed1i \u01b0u h\u00f3a hi\u1ec7u su\u1ea5t m\u1ea1ng v\u00e0 gi\u1ea3m nguy c\u01a1 t\u1eafc ngh\u1ebdn li\u00ean quan \u0111\u1ebfn DNS.<\/p>\n<\/li>\n<\/ol>\n<h3>V\u1ea5n \u0111\u1ec1 v\u00e0 gi\u1ea3i ph\u00e1p:<\/h3>\n<ol>\n<li>\n<p><strong>B\u1ed9 \u0111\u1ec7m c\u0169<\/strong>: B\u1ea3n ghi DNS \u0111\u00e3 h\u1ebft h\u1ea1n ho\u1eb7c kh\u00f4ng ch\u00ednh x\u00e1c trong b\u1ed9 \u0111\u1ec7m c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn s\u1ef1 c\u1ed1 khi truy c\u1eadp trang web. \u0110\u1ec3 gi\u1ea3i quy\u1ebft v\u1ea5n \u0111\u1ec1 n\u00e0y, tr\u00ecnh ph\u00e2n gi\u1ea3i DNS \u0111\u1ecbnh k\u1ef3 l\u00e0m m\u1edbi b\u1ed9 \u0111\u1ec7m c\u1ee7a h\u1ecd b\u1eb1ng c\u00e1ch truy v\u1ea5n l\u1ea1i c\u00e1c m\u00e1y ch\u1ee7 c\u00f3 th\u1ea9m quy\u1ec1n.<\/p>\n<\/li>\n<li>\n<p><strong>Ng\u1ed9 \u0111\u1ed9c b\u1ed9 \u0111\u1ec7m<\/strong>: Ng\u1ed9 \u0111\u1ed9c b\u1ed9 \u0111\u1ec7m DNS c\u00f3 th\u1ec3 x\u1ea3y ra khi k\u1ebb t\u1ea5n c\u00f4ng thao t\u00fang b\u1ea3n ghi DNS trong b\u1ed9 \u0111\u1ec7m, d\u1eabn \u0111\u1ebfn vi\u1ec7c ng\u01b0\u1eddi d\u00f9ng b\u1ecb chuy\u1ec3n h\u01b0\u1edbng \u0111\u1ebfn c\u00e1c trang web \u0111\u1ed9c h\u1ea1i. Tri\u1ec3n khai DNSSEC (Ti\u1ec7n \u00edch m\u1edf r\u1ed9ng b\u1ea3o m\u1eadt h\u1ec7 th\u1ed1ng t\u00ean mi\u1ec1n) gi\u00fap ng\u0103n ch\u1eb7n c\u00e1c cu\u1ed9c t\u1ea5n c\u00f4ng \u0111\u1ea7u \u0111\u1ed9c b\u1ed9 \u0111\u1ec7m.<\/p>\n<\/li>\n<li>\n<p><strong>Gi\u00e1 tr\u1ecb TTL l\u1edbn<\/strong>: Vi\u1ec7c \u0111\u1eb7t gi\u00e1 tr\u1ecb TTL qu\u00e1 d\u00e0i cho b\u1ea3n ghi DNS c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn c\u1eadp nh\u1eadt b\u1ecb tr\u00ec ho\u00e3n, khi\u1ebfn vi\u1ec7c chuy\u1ec3n h\u01b0\u1edbng l\u01b0u l\u01b0\u1ee3ng truy c\u1eadp tr\u1edf n\u00ean kh\u00f3 kh\u0103n trong tr\u01b0\u1eddng h\u1ee3p m\u00e1y ch\u1ee7 thay \u0111\u1ed5i. Qu\u1ea3n l\u00fd TTL c\u1ea9n th\u1eadn l\u00e0 c\u1ea7n thi\u1ebft \u0111\u1ec3 tr\u00e1nh v\u1ea5n \u0111\u1ec1 n\u00e0y.<\/p>\n<\/li>\n<\/ol>\n<h2>C\u00e1c \u0111\u1eb7c \u0111i\u1ec3m ch\u00ednh v\u00e0 so s\u00e1nh kh\u00e1c v\u1edbi c\u00e1c thu\u1eadt ng\u1eef t\u01b0\u01a1ng t\u1ef1<\/h2>\n<table>\n<thead>\n<tr>\n<th>Thu\u1eadt ng\u1eef<\/th>\n<th>S\u1ef1 mi\u00eau t\u1ea3<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>B\u1ed9 \u0111\u1ec7m DNS<\/td>\n<td>L\u01b0u tr\u1eef t\u1ea1m th\u1eddi k\u1ebft qu\u1ea3 truy v\u1ea5n DNS \u0111\u1ec3 gi\u1ea3i quy\u1ebft nhanh h\u01a1n<\/td>\n<\/tr>\n<tr>\n<td>Tr\u00ecnh ph\u00e2n gi\u1ea3i DNS<\/td>\n<td>M\u00e1y ch\u1ee7 ch\u1ecbu tr\u00e1ch nhi\u1ec7m truy v\u1ea5n c\u00e1c b\u1ea3n ghi DNS thay m\u1eb7t cho kh\u00e1ch h\u00e0ng<\/td>\n<\/tr>\n<tr>\n<td>Chuy\u1ec3n ti\u1ebfp DNS<\/td>\n<td>M\u00e1y ch\u1ee7 chuy\u1ec3n ti\u1ebfp c\u00e1c truy v\u1ea5n DNS \u0111\u1ebfn c\u00e1c m\u00e1y ch\u1ee7 DNS kh\u00e1c<\/td>\n<\/tr>\n<tr>\n<td>DNSSEC<\/td>\n<td>M\u1ed9t b\u1ed9 ti\u1ec7n \u00edch m\u1edf r\u1ed9ng t\u0103ng th\u00eam t\u00ednh b\u1ea3o m\u1eadt cho giao th\u1ee9c DNS<\/td>\n<\/tr>\n<tr>\n<td>C\u01a1 ch\u1ebf b\u1ed9 nh\u1edb \u0111\u1ec7m<\/td>\n<td>M\u1ed9t quy tr\u00ecnh l\u01b0u tr\u1eef d\u1eef li\u1ec7u th\u01b0\u1eddng xuy\u00ean truy c\u1eadp \u0111\u1ec3 truy xu\u1ea5t nhanh<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Tri\u1ec3n v\u1ecdng v\u00e0 c\u00f4ng ngh\u1ec7 c\u1ee7a t\u01b0\u01a1ng lai li\u00ean quan \u0111\u1ebfn DNS cache<\/h2>\n<p>T\u01b0\u01a1ng lai c\u1ee7a b\u1ed9 \u0111\u1ec7m DNS g\u1eafn li\u1ec1n v\u1edbi nh\u1eefng ti\u1ebfn b\u1ed9 v\u1ec1 c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng v\u00e0 b\u1ea3o m\u1eadt m\u1ea1ng. Khi vi\u1ec7c s\u1eed d\u1ee5ng internet ti\u1ebfp t\u1ee5c ph\u00e1t tri\u1ec3n, vi\u1ec7c t\u1ed1i \u01b0u h\u00f3a \u0111\u1ed9 ph\u00e2n gi\u1ea3i DNS s\u1ebd v\u1eabn r\u1ea5t quan tr\u1ecdng. M\u1ed9t s\u1ed1 ph\u00e1t tri\u1ec3n ti\u1ec1m n\u0103ng bao g\u1ed3m:<\/p>\n<ol>\n<li>\n<p><strong>C\u1ea3i thi\u1ec7n qu\u1ea3n l\u00fd TTL<\/strong>: C\u00e1c thu\u1eadt to\u00e1n th\u00f4ng minh h\u01a1n c\u00f3 th\u1ec3 t\u1ef1 \u0111\u1ed9ng \u0111i\u1ec1u ch\u1ec9nh c\u00e1c gi\u00e1 tr\u1ecb TTL d\u1ef1a tr\u00ean c\u00e1c m\u1eabu truy v\u1ea5n l\u1ecbch s\u1eed, \u0111\u1ea3m b\u1ea3o duy tr\u00ec b\u1ed9 nh\u1edb \u0111\u1ec7m t\u1ed1i \u01b0u v\u00e0 gi\u1ea3m thi\u1ec3u d\u1eef li\u1ec7u c\u0169.<\/p>\n<\/li>\n<li>\n<p><strong>B\u1ed9 \u0111\u1ec7m DNS ph\u00e2n t\u00e1n<\/strong>: Vi\u1ec7c tri\u1ec3n khai c\u00e1c h\u1ec7 th\u1ed1ng b\u1ed9 \u0111\u1ec7m ph\u00e2n t\u00e1n c\u00f3 th\u1ec3 gi\u1ea3m t\u1ea3i h\u01a1n n\u1eefa cho c\u00e1c b\u1ed9 ph\u00e2n gi\u1ea3i ri\u00eang l\u1ebb v\u00e0 cung c\u1ea5p kh\u1ea3 n\u0103ng d\u1ef1 ph\u00f2ng, n\u00e2ng cao t\u00ednh m\u1ea1nh m\u1ebd t\u1ed5ng th\u1ec3 c\u1ee7a DNS.<\/p>\n<\/li>\n<li>\n<p><strong>B\u1ed9 nh\u1edb \u0111\u1ec7m d\u1ef1a tr\u00ean AI<\/strong>: Tr\u00ed tu\u1ec7 nh\u00e2n t\u1ea1o c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 d\u1ef1 \u0111o\u00e1n c\u00e1c mi\u1ec1n \u0111\u01b0\u1ee3c truy c\u1eadp th\u01b0\u1eddng xuy\u00ean v\u00e0 l\u01b0u tr\u1eef c\u00e1c b\u1ea3n ghi c\u00f3 li\u00ean quan, c\u1ea3i thi\u1ec7n h\u01a1n n\u1eefa th\u1eddi gian ph\u1ea3n h\u1ed3i v\u00e0 tr\u1ea3i nghi\u1ec7m ng\u01b0\u1eddi d\u00f9ng.<\/p>\n<\/li>\n<\/ol>\n<h2>C\u00e1ch s\u1eed d\u1ee5ng ho\u1eb7c li\u00ean k\u1ebft m\u00e1y ch\u1ee7 proxy v\u1edbi b\u1ed9 \u0111\u1ec7m DNS<\/h2>\n<p>M\u00e1y ch\u1ee7 proxy c\u00f3 th\u1ec3 n\u00e2ng cao hi\u1ec7u qu\u1ea3 c\u1ee7a b\u1ed9 \u0111\u1ec7m DNS theo nhi\u1ec1u c\u00e1ch:<\/p>\n<ol>\n<li>\n<p><strong>Proxy b\u1ed9 nh\u1edb \u0111\u1ec7m<\/strong>: M\u1ed9t s\u1ed1 m\u00e1y ch\u1ee7 proxy l\u01b0u tr\u1eef b\u1ea3n ghi DNS c\u1ee5c b\u1ed9, gi\u1ea3m th\u1eddi gian ph\u00e2n gi\u1ea3i DNS cho c\u00e1c mi\u1ec1n \u0111\u01b0\u1ee3c truy c\u1eadp th\u01b0\u1eddng xuy\u00ean.<\/p>\n<\/li>\n<li>\n<p><strong>L\u1ecdc n\u1ed9i dung<\/strong>: Proxy c\u00f3 kh\u1ea3 n\u0103ng l\u1ecdc DNS c\u00f3 th\u1ec3 ch\u1eb7n quy\u1ec1n truy c\u1eadp v\u00e0o c\u00e1c mi\u1ec1n \u0111\u1ed9c h\u1ea1i, cung c\u1ea5p th\u00eam l\u1edbp b\u1ea3o m\u1eadt.<\/p>\n<\/li>\n<li>\n<p><strong>C\u00e2n b\u1eb1ng t\u1ea3i<\/strong>: Proxy c\u00f3 th\u1ec3 ph\u00e2n ph\u1ed1i c\u00e1c truy v\u1ea5n DNS tr\u00ean nhi\u1ec1u tr\u00ecnh ph\u00e2n gi\u1ea3i, c\u00e2n b\u1eb1ng t\u1ea3i truy v\u1ea5n v\u00e0 c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t.<\/p>\n<\/li>\n<\/ol>\n<h2>Li\u00ean k\u1ebft li\u00ean quan<\/h2>\n<p>\u0110\u1ec3 bi\u1ebft th\u00eam th\u00f4ng tin v\u1ec1 b\u1ed9 \u0111\u1ec7m DNS, h\u00e3y xem x\u00e9t kh\u00e1m ph\u00e1 c\u00e1c t\u00e0i nguy\u00ean sau:<\/p>\n<ul>\n<li><a href=\"https:\/\/www.icann.org\/en\/system\/files\/files\/dns-for-dummies-12dec11-en.pdf\" target=\"_new\" rel=\"noopener nofollow\">T\u1ed5ng quan v\u1ec1 h\u1ec7 th\u1ed1ng t\u00ean mi\u1ec1n (DNS)<\/a><\/li>\n<li><a href=\"https:\/\/www.cloudflare.com\/learning\/dns\/dns-cache-poisoning\/\" target=\"_new\" rel=\"noopener nofollow\">Gi\u1ea3i th\u00edch v\u1ec1 ng\u1ed9 \u0111\u1ed9c b\u1ed9 \u0111\u1ec7m DNS<\/a><\/li>\n<li><a href=\"https:\/\/www.akamai.com\/us\/en\/resources\/learn-understand\/understanding-dns-caching-and-ttls.jsp\" target=\"_new\" rel=\"noopener nofollow\">T\u00ecm hi\u1ec3u b\u1ed9 nh\u1edb \u0111\u1ec7m DNS v\u00e0 TTL<\/a><\/li>\n<\/ul>","protected":false},"featured_media":476884,"menu_order":0,"template":"","meta":{"_acf_changed":false,"content-type":"","inline_featured_image":false,"footnotes":""},"class_list":["post-476883","wiki","type-wiki","status-publish","has-post-thumbnail","hentry"],"acf":{"faq_title":"Frequently Asked Questions about <mark>DNS Cache: A Comprehensive Overview<\/mark>","faq_items":[{"question":"What is DNS cache, and how does it work?","answer":"<p>DNS cache, also known as Domain Name System cache, is a temporary storage location that stores previously resolved domain name records. It works by retaining the results of previous DNS lookups, allowing quick retrieval of IP addresses for domain names without having to contact authoritative DNS servers. This caching mechanism reduces query response time and network load, making web browsing more efficient.<\/p>"},{"question":"Who developed DNS cache, and when was it first introduced?","answer":"<p>The concept of DNS caching was introduced in 1983 by Paul Mockapetris and Jon Postel when they developed the Domain Name System (DNS). The DNS cache was designed to improve the efficiency of DNS resolution, reducing the time required to translate domain names into IP addresses and vice versa.<\/p>"},{"question":"What are the types of DNS cache?","answer":"<p>There are two primary types of DNS cache:<\/p><ol><li><p>Client-Side DNS Cache: This cache exists on individual user devices (e.g., computers, smartphones, routers) and stores DNS records for domains accessed by the user.<\/p><\/li><li><p>Resolver-Side DNS Cache: Also known as Recursive DNS Cache, this cache is managed by DNS resolvers (e.g., ISP DNS servers, public DNS servers) and serves multiple users, reducing overall DNS query traffic.<\/p><\/li><\/ol>"},{"question":"What are the key features of DNS cache?","answer":"<p>DNS cache offers several key features:<\/p><ol><li><p>Faster Response Times: Previously resolved DNS queries are retrieved from the cache, resulting in quicker domain name resolutions.<\/p><\/li><li><p>Reduced Network Load: DNS caching minimizes the number of queries sent to authoritative DNS servers, optimizing network performance.<\/p><\/li><li><p>Improved Resilience: Cached DNS records can still be used to resolve domain names even if authoritative servers experience downtime.<\/p><\/li><\/ol>"},{"question":"What are some problems related to DNS cache usage, and how can they be solved?","answer":"<p>Common issues related to DNS cache usage include:<\/p><ol><li><p>Stale Cache: Expired or incorrect DNS records in the cache can lead to issues accessing websites. The cache can be periodically refreshed by re-querying authoritative servers.<\/p><\/li><li><p>Cache Poisoning: DNS cache poisoning can occur when attackers manipulate DNS records in the cache. Implementing DNSSEC helps prevent such attacks.<\/p><\/li><li><p>Large TTL Values: Setting excessively long TTL values for DNS records can result in delayed updates during server changes. Careful TTL management is necessary to avoid this problem.<\/p><\/li><\/ol>"},{"question":"How can proxy servers be associated with DNS cache?","answer":"<p>Proxy servers can enhance DNS cache efficiency in various ways:<\/p><ol><li><p>Caching Proxies: Some proxy servers cache DNS records locally, reducing DNS resolution time for frequently accessed domains.<\/p><\/li><li><p>Content Filtering: Proxies with DNS filtering capabilities can block access to malicious domains, providing an additional layer of security.<\/p><\/li><li><p>Load Balancing: Proxies can distribute DNS queries across multiple resolvers, balancing the query load and improving performance.<\/p><\/li><\/ol>"},{"question":"What does the future hold for DNS cache technology?","answer":"<p>The future of DNS cache is likely to see advancements in network infrastructure and security. Possible developments may include improved TTL management, distributed DNS cache systems, and AI-driven caching to further enhance DNS resolution efficiency.<\/p>"},{"question":"How can I learn more about DNS cache?","answer":"<p>For more in-depth information about DNS cache, you can explore additional resources such as:<\/p><ul><li><a href=\"https:\/\/www.icann.org\/en\/system\/files\/files\/dns-for-dummies-12dec11-en.pdf\" target=\"_new\">Domain Name System (DNS) Overview<\/a><\/li><li><a href=\"https:\/\/www.cloudflare.com\/learning\/dns\/dns-cache-poisoning\/\" target=\"_new\">DNS Cache Poisoning Explained<\/a><\/li><li><a href=\"https:\/\/www.akamai.com\/us\/en\/resources\/learn-understand\/understanding-dns-caching-and-ttls.jsp\" target=\"_new\">Understanding DNS Caching and TTLs<\/a><\/li><\/ul>"}]},"_links":{"self":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/wiki\/476883","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/types\/wiki"}],"version-history":[{"count":0,"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/wiki\/476883\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/media\/476884"}],"wp:attachment":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/media?parent=476883"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}