{"id":476927,"date":"2023-08-09T09:05:02","date_gmt":"2023-08-09T09:05:02","guid":{"rendered":""},"modified":"2023-09-05T11:13:40","modified_gmt":"2023-09-05T11:13:40","slug":"dns-redundancy","status":"publish","type":"wiki","link":"https:\/\/oneproxy.pro\/vn\/wiki\/dns-redundancy\/","title":{"rendered":"D\u1ef1 ph\u00f2ng DNS"},"content":{"rendered":"<h2>Gi\u1edbi thi\u1ec7u<\/h2>\n<p>D\u1ef1 ph\u00f2ng DNS l\u00e0 m\u1ed9t kh\u00eda c\u1ea1nh quan tr\u1ecdng \u0111\u1ec3 duy tr\u00ec c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng internet \u1ed5n \u0111\u1ecbnh v\u00e0 \u0111\u00e1ng tin c\u1eady. N\u00f3 li\u00ean quan \u0111\u1ebfn vi\u1ec7c tri\u1ec3n khai c\u00e1c m\u00e1y ch\u1ee7 DNS d\u1ef1 ph\u00f2ng \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o t\u00ednh s\u1eb5n s\u00e0ng cao, kh\u1ea3 n\u0103ng ch\u1ecbu l\u1ed7i v\u00e0 ph\u00e2n ph\u1ed1i t\u1ea3i cho qu\u00e1 tr\u00ecnh ph\u00e2n gi\u1ea3i t\u00ean mi\u1ec1n. B\u1eb1ng c\u00e1ch ph\u00e2n ph\u1ed1i t\u1ea3i tr\u00ean nhi\u1ec1u m\u00e1y ch\u1ee7, d\u1ef1 ph\u00f2ng DNS \u0111\u1ea3m b\u1ea3o r\u1eb1ng ng\u01b0\u1eddi d\u00f9ng c\u00f3 th\u1ec3 truy c\u1eadp c\u00e1c trang web v\u00e0 d\u1ecbch v\u1ee5 tr\u1ef1c tuy\u1ebfn m\u00e0 kh\u00f4ng b\u1ecb gi\u00e1n \u0111o\u1ea1n, ngay c\u1ea3 khi g\u1eb7p l\u1ed7i ph\u1ea7n c\u1ee9ng ho\u1eb7c t\u1ea5n c\u00f4ng DDoS. Trong b\u00e0i vi\u1ebft n\u00e0y, ch\u00fang t\u00f4i s\u1ebd \u0111i s\u00e2u v\u00e0o l\u1ecbch s\u1eed, ho\u1ea1t \u0111\u1ed9ng, lo\u1ea1i h\u00ecnh v\u00e0 tri\u1ec3n v\u1ecdng trong t\u01b0\u01a1ng lai c\u1ee7a d\u1ef1 ph\u00f2ng DNS, t\u1eadp trung c\u1ee5 th\u1ec3 v\u00e0o m\u1ee9c \u0111\u1ed9 li\u00ean quan c\u1ee7a n\u00f3 \u0111\u1ed1i v\u1edbi nh\u00e0 cung c\u1ea5p m\u00e1y ch\u1ee7 proxy, OneProxy.<\/p>\n<h2>Ngu\u1ed3n g\u1ed1c v\u00e0 s\u1ef1 \u0111\u1ec1 c\u1eadp s\u1edbm c\u1ee7a d\u1ef1 ph\u00f2ng DNS<\/h2>\n<p>Kh\u00e1i ni\u1ec7m d\u1ef1 ph\u00f2ng DNS xu\u1ea5t hi\u1ec7n c\u00f9ng v\u1edbi s\u1ef1 ph\u00e1t tri\u1ec3n c\u1ee7a H\u1ec7 th\u1ed1ng t\u00ean mi\u1ec1n (DNS) v\u00e0o nh\u1eefng n\u0103m 1980. Ban \u0111\u1ea7u, DNS d\u1ef1a tr\u00ean m\u1ed9t m\u00e1y ch\u1ee7 duy nh\u1ea5t, \u0111i\u1ec1u n\u00e0y c\u00f3 nh\u1eefng h\u1ea1n ch\u1ebf \u0111\u00e1ng k\u1ec3 li\u00ean quan \u0111\u1ebfn \u0111\u1ed9 tin c\u1eady v\u00e0 hi\u1ec7u su\u1ea5t. \u0110\u1ec1 c\u1eadp \u0111\u1ea7u ti\u00ean v\u1ec1 nhu c\u1ea7u d\u1ef1 ph\u00f2ng trong DNS c\u00f3 th\u1ec3 b\u1eaft ngu\u1ed3n t\u1eeb RFC 882, \u0111\u01b0\u1ee3c xu\u1ea5t b\u1ea3n v\u00e0o th\u00e1ng 11 n\u0103m 1983, trong \u0111\u00f3 n\u00eau b\u1eadt t\u1ea7m quan tr\u1ecdng c\u1ee7a h\u1ec7 th\u1ed1ng DNS ph\u00e2n t\u00e1n trong vi\u1ec7c gi\u1ea3m thi\u1ec3u c\u00e1c \u0111i\u1ec3m l\u1ed7i \u0111\u01a1n l\u1ebb.<\/p>\n<h2>Hi\u1ec3u v\u1ec1 d\u1ef1 ph\u00f2ng DNS<\/h2>\n<p>D\u1ef1 ph\u00f2ng DNS \u0111\u1ea1t \u0111\u01b0\u1ee3c b\u1eb1ng c\u00e1ch tri\u1ec3n khai nhi\u1ec1u m\u00e1y ch\u1ee7 DNS, th\u01b0\u1eddng \u0111\u01b0\u1ee3c t\u1ed5 ch\u1ee9c theo ki\u1ebfn tr\u00fac ph\u00e2n c\u1ea5p ho\u1eb7c ph\u00e2n t\u00e1n. M\u1ed7i m\u00e1y ch\u1ee7 DNS duy tr\u00ec m\u1ed9t b\u1ea3n sao d\u1eef li\u1ec7u v\u00f9ng DNS, ch\u1ee9a \u00e1nh x\u1ea1 t\u00ean mi\u1ec1n t\u1edbi \u0111\u1ecba ch\u1ec9 IP. Khi thi\u1ebft b\u1ecb c\u1ee7a ng\u01b0\u1eddi d\u00f9ng b\u1eaft \u0111\u1ea7u truy v\u1ea5n DNS, n\u00f3 c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c chuy\u1ec3n h\u01b0\u1edbng \u0111\u1ebfn b\u1ea5t k\u1ef3 m\u00e1y ch\u1ee7 DNS d\u1ef1 ph\u00f2ng n\u00e0o, sau \u0111\u00f3 ph\u1ea3n h\u1ed3i b\u1eb1ng \u0111\u1ecba ch\u1ec9 IP th\u00edch h\u1ee3p cho mi\u1ec1n \u0111\u01b0\u1ee3c y\u00eau c\u1ea7u.<\/p>\n<h2>C\u1ea5u tr\u00fac b\u00ean trong v\u00e0 ho\u1ea1t \u0111\u1ed9ng c\u1ee7a d\u1ef1 ph\u00f2ng DNS<\/h2>\n<p>C\u1ea5u tr\u00fac b\u00ean trong c\u1ee7a d\u1ef1 ph\u00f2ng DNS li\u00ean quan \u0111\u1ebfn vi\u1ec7c thi\u1ebft l\u1eadp m\u00e1y ch\u1ee7 DNS ch\u00ednh v\u00e0 ph\u1ee5, c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi t\u01b0\u01a1ng \u1ee9ng l\u00e0 m\u00e1y ch\u1ee7 ch\u00ednh v\u00e0 ph\u1ee5. M\u00e1y ch\u1ee7 DNS ch\u00ednh c\u00f3 th\u1ea9m quy\u1ec1n \u0111\u1ed1i v\u1edbi m\u1ed9t v\u00f9ng DNS c\u1ee5 th\u1ec3 v\u00e0 gi\u1eef b\u1ea3n sao ch\u00ednh c\u1ee7a d\u1eef li\u1ec7u v\u00f9ng. M\u00e1y ch\u1ee7 DNS ph\u1ee5 th\u01b0\u1eddng xuy\u00ean \u0111\u1ed3ng b\u1ed9 h\u00f3a v\u1edbi m\u00e1y ch\u1ee7 ch\u00ednh \u0111\u1ec3 nh\u1eadn c\u00e1c b\u1ea3n c\u1eadp nh\u1eadt cho d\u1eef li\u1ec7u v\u00f9ng. Qu\u00e1 tr\u00ecnh \u0111\u1ed3ng b\u1ed9 h\u00f3a n\u00e0y, \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 chuy\u1ec3n v\u00f9ng, \u0111\u1ea3m b\u1ea3o r\u1eb1ng t\u1ea5t c\u1ea3 c\u00e1c m\u00e1y ch\u1ee7 th\u1ee9 c\u1ea5p \u0111\u1ec1u c\u00f3 th\u00f4ng tin nh\u1ea5t qu\u00e1n v\u00e0 c\u1eadp nh\u1eadt.<\/p>\n<p>Khi nh\u1eadn \u0111\u01b0\u1ee3c truy v\u1ea5n DNS, b\u1ea5t k\u1ef3 m\u00e1y ch\u1ee7 DNS d\u1ef1 ph\u00f2ng n\u00e0o c\u0169ng c\u00f3 th\u1ec3 ph\u1ea3n h\u1ed3i, d\u1ef1a tr\u00ean c\u00e1c y\u1ebfu t\u1ed1 nh\u01b0 \u0111\u1ed9 g\u1ea7n, t\u1ea3i hi\u1ec7n t\u1ea1i ho\u1eb7c thu\u1eadt to\u00e1n xoay \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh tr\u01b0\u1edbc. Ph\u00e2n ph\u1ed1i t\u1ea3i n\u00e0y kh\u00f4ng ch\u1ec9 c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t ph\u00e2n gi\u1ea3i DNS m\u00e0 c\u00f2n cung c\u1ea5p kh\u1ea3 n\u0103ng ch\u1ecbu l\u1ed7i. N\u1ebfu m\u1ed9t m\u00e1y ch\u1ee7 kh\u00f4ng th\u1ec3 truy c\u1eadp \u0111\u01b0\u1ee3c ho\u1eb7c g\u1eb7p s\u1ef1 c\u1ed1 th\u00ec c\u00e1c m\u00e1y ch\u1ee7 kh\u00e1c v\u1eabn c\u00f3 th\u1ec3 x\u1eed l\u00fd c\u00e1c truy v\u1ea5n DNS \u0111\u1ebfn.<\/p>\n<h2>C\u00e1c t\u00ednh n\u0103ng ch\u00ednh c\u1ee7a d\u1ef1 ph\u00f2ng DNS<\/h2>\n<p>C\u00e1c t\u00ednh n\u0103ng ch\u00ednh c\u1ee7a d\u1ef1 ph\u00f2ng DNS c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c t\u00f3m t\u1eaft nh\u01b0 sau:<\/p>\n<ol>\n<li>\n<p><strong>T\u00ednh s\u1eb5n s\u00e0ng cao:<\/strong> D\u1ef1 ph\u00f2ng DNS \u0111\u1ea3m b\u1ea3o r\u1eb1ng c\u00e1c d\u1ecbch v\u1ee5 DNS v\u1eabn c\u00f3 th\u1ec3 truy c\u1eadp \u0111\u01b0\u1ee3c ngay c\u1ea3 khi m\u1ed9t s\u1ed1 m\u00e1y ch\u1ee7 b\u1ecb l\u1ed7i ho\u1eb7c g\u1eb7p s\u1ef1 c\u1ed1 gi\u00e1n \u0111o\u1ea1n.<\/p>\n<\/li>\n<li>\n<p><strong>Ph\u00e2n ph\u1ed1i t\u1ea3i:<\/strong> Vi\u1ec7c ph\u00e2n ph\u1ed1i truy v\u1ea5n DNS tr\u00ean nhi\u1ec1u m\u00e1y ch\u1ee7 s\u1ebd ng\u0103n ch\u1eb7n t\u00ecnh tr\u1ea1ng qu\u00e1 t\u1ea3i c\u1ee7a t\u1eebng m\u00e1y ch\u1ee7, d\u1eabn \u0111\u1ebfn hi\u1ec7u su\u1ea5t t\u1ed5ng th\u1ec3 t\u1ed1t h\u01a1n.<\/p>\n<\/li>\n<li>\n<p><strong>Dung sai l\u1ed7i:<\/strong> M\u00e1y ch\u1ee7 d\u1ef1 ph\u00f2ng cung c\u1ea5p kh\u1ea3 n\u0103ng chuy\u1ec3n \u0111\u1ed5i d\u1ef1 ph\u00f2ng, gi\u1ea3m nguy c\u01a1 gi\u00e1n \u0111o\u1ea1n d\u1ecbch v\u1ee5 do l\u1ed7i ph\u1ea7n c\u1ee9ng ho\u1eb7c ph\u1ea7n m\u1ec1m.<\/p>\n<\/li>\n<li>\n<p><strong>D\u1ef1 ph\u00f2ng \u0111\u1ecba l\u00fd:<\/strong> M\u1ed9t s\u1ed1 tri\u1ec3n khai d\u1ef1 ph\u00f2ng DNS tr\u1ea3i r\u1ed9ng tr\u00ean nhi\u1ec1u v\u1ecb tr\u00ed \u0111\u1ecba l\u00fd, t\u0103ng c\u01b0\u1eddng kh\u1ea3 n\u0103ng ph\u1ee5c h\u1ed3i tr\u01b0\u1edbc t\u00ecnh tr\u1ea1ng ng\u1eebng ho\u1ea1t \u0111\u1ed9ng trong khu v\u1ef1c ho\u1eb7c s\u1ef1 c\u1ed1 m\u1ea1ng.<\/p>\n<\/li>\n<li>\n<p><strong>C\u1eadp nh\u1eadt \u0111\u1ed9ng:<\/strong> D\u1ef1 ph\u00f2ng DNS h\u1ed7 tr\u1ee3 c\u1eadp nh\u1eadt \u0111\u1ed9ng cho b\u1ea3n ghi DNS, cho ph\u00e9p thay \u0111\u1ed5i \u00e1nh x\u1ea1 DNS theo th\u1eddi gian th\u1ef1c.<\/p>\n<\/li>\n<\/ol>\n<h2>C\u00e1c lo\u1ea1i d\u1ef1 ph\u00f2ng DNS<\/h2>\n<p>C\u00f3 m\u1ed9t s\u1ed1 lo\u1ea1i d\u1ef1 ph\u00f2ng DNS, m\u1ed7i lo\u1ea1i mang l\u1ea1i nh\u1eefng l\u1ee3i \u00edch ri\u00eang. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 danh s\u00e1ch c\u00e1c lo\u1ea1i d\u1ef1 ph\u00f2ng DNS ph\u1ed5 bi\u1ebfn:<\/p>\n<table>\n<thead>\n<tr>\n<th>Lo\u1ea1i d\u1ef1 ph\u00f2ng DNS<\/th>\n<th>S\u1ef1 mi\u00eau t\u1ea3<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Ti\u1ec3u h\u1ecdc-Trung h\u1ecdc<\/td>\n<td>Trong thi\u1ebft l\u1eadp n\u00e0y, m\u1ed9t m\u00e1y ch\u1ee7 DNS ch\u00ednh gi\u1eef b\u1ea3n sao ch\u00ednh c\u1ee7a d\u1eef li\u1ec7u v\u00f9ng, trong khi nhi\u1ec1u m\u00e1y ch\u1ee7 ph\u1ee5 \u0111\u1ed3ng b\u1ed9 h\u00f3a v\u1edbi m\u00e1y ch\u1ee7 ch\u00ednh.<\/td>\n<\/tr>\n<tr>\n<td>Ch\u1ee7 nh\u00e2n \u1ea9n gi\u1ea5u<\/td>\n<td>M\u00e1y ch\u1ee7 ch\u00ednh \u1ea9n l\u00e0 m\u00e1y ch\u1ee7 DNS ch\u00ednh kh\u00f4ng th\u1ec3 truy c\u1eadp c\u00f4ng khai, gi\u00fap gi\u1ea3m nguy c\u01a1 b\u1ecb t\u1ea5n c\u00f4ng tr\u1ef1c ti\u1ebfp v\u00e0o m\u00e1y ch\u1ee7 ch\u00ednh. N\u00f3 sao ch\u00e9p d\u1eef li\u1ec7u \u0111\u1ebfn c\u00e1c m\u00e1y ch\u1ee7 th\u1ee9 c\u1ea5p c\u00f4ng khai.<\/td>\n<\/tr>\n<tr>\n<td>S\u01b0 ph\u1ee5 s\u01b0 ph\u1ee5<\/td>\n<td>D\u1ef1 ph\u00f2ng Master-Master s\u1eed d\u1ee5ng nhi\u1ec1u m\u00e1y ch\u1ee7 ch\u00ednh v\u00e0 m\u1ed7i m\u00e1y ch\u1ee7 c\u00f3 th\u1ec3 ch\u1ea5p nh\u1eadn c\u00e1c b\u1ea3n c\u1eadp nh\u1eadt cho d\u1eef li\u1ec7u v\u00f9ng, mang l\u1ea1i s\u1ef1 linh ho\u1ea1t h\u01a1n trong vi\u1ec7c qu\u1ea3n l\u00fd b\u1ea3n ghi DNS.<\/td>\n<\/tr>\n<tr>\n<td>Anycast<\/td>\n<td>D\u1ef1 ph\u00f2ng Anycast li\u00ean quan \u0111\u1ebfn vi\u1ec7c tri\u1ec3n khai c\u00e1c m\u00e1y ch\u1ee7 DNS gi\u1ed1ng h\u1ec7t nhau \u1edf nhi\u1ec1u v\u1ecb tr\u00ed kh\u00e1c nhau. C\u00e1c truy v\u1ea5n DNS \u0111\u01b0\u1ee3c chuy\u1ec3n h\u01b0\u1edbng \u0111\u1ebfn m\u00e1y ch\u1ee7 kh\u1ea3 d\u1ee5ng g\u1ea7n nh\u1ea5t, t\u1ed1i \u01b0u h\u00f3a th\u1eddi gian ph\u1ea3n h\u1ed3i v\u00e0 gi\u1ea3m thi\u1ec3u c\u00e1c cu\u1ed9c t\u1ea5n c\u00f4ng DDoS.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>S\u1eed d\u1ee5ng d\u1ef1 ph\u00f2ng DNS: Nh\u1eefng th\u00e1ch th\u1ee9c v\u00e0 gi\u1ea3i ph\u00e1p<\/h2>\n<p>D\u1ef1 ph\u00f2ng DNS mang l\u1ea1i nhi\u1ec1u l\u1ee3i \u00edch nh\u01b0ng vi\u1ec7c tri\u1ec3n khai n\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 kh\u00f4ng c\u00f3 th\u00e1ch th\u1ee9c. M\u1ed9t s\u1ed1 th\u00e1ch th\u1ee9c ph\u1ed5 bi\u1ebfn bao g\u1ed3m:<\/p>\n<ol>\n<li>\n<p><strong>\u0110\u1ed9 tr\u1ec5 \u0111\u1ed3ng b\u1ed9 h\u00f3a:<\/strong> Vi\u1ec7c gi\u1eef c\u00e1c m\u00e1y ch\u1ee7 ph\u1ee5 \u0111\u1ed3ng b\u1ed9 v\u1edbi m\u00e1y ch\u1ee7 ch\u00ednh c\u00f3 th\u1ec3 g\u00e2y ra s\u1ef1 ch\u1eadm tr\u1ec5 trong vi\u1ec7c truy\u1ec1n b\u00e1 c\u00e1c b\u1ea3n c\u1eadp nh\u1eadt.<\/p>\n<\/li>\n<li>\n<p><strong>T\u00ednh nh\u1ea5t qu\u00e1n c\u1ee7a b\u1ed9 \u0111\u1ec7m DNS:<\/strong> D\u1eef li\u1ec7u DNS \u0111\u01b0\u1ee3c l\u01b0u trong b\u1ed9 nh\u1edb \u0111\u1ec7m trong thi\u1ebft b\u1ecb kh\u00e1ch v\u00e0 tr\u00ecnh ph\u00e2n gi\u1ea3i trung gian c\u00f3 th\u1ec3 g\u00e2y ra s\u1ef1 kh\u00f4ng nh\u1ea5t qu\u00e1n khi b\u1ea3n ghi DNS thay \u0111\u1ed5i.<\/p>\n<\/li>\n<li>\n<p><strong>T\u0103ng \u0111\u1ed9 ph\u1ee9c t\u1ea1p:<\/strong> Vi\u1ec7c qu\u1ea3n l\u00fd nhi\u1ec1u m\u00e1y ch\u1ee7 DNS \u0111\u00f2i h\u1ecfi ph\u1ea3i l\u1eadp k\u1ebf ho\u1ea1ch v\u00e0 qu\u1ea3n l\u00fd c\u1ea9n th\u1eadn.<\/p>\n<\/li>\n<\/ol>\n<p>\u0110\u1ec3 gi\u1ea3i quy\u1ebft nh\u1eefng th\u00e1ch th\u1ee9c n\u00e0y, c\u00e1c gi\u1ea3i ph\u00e1p bao g\u1ed3m tri\u1ec3n khai c\u00e1c gi\u00e1 tr\u1ecb TTL (Th\u1eddi gian t\u1ed3n t\u1ea1i) ng\u1eafn h\u01a1n cho b\u1ea3n ghi DNS \u0111\u1ec3 gi\u1ea3m thi\u1ec3u c\u00e1c v\u1ea5n \u0111\u1ec1 v\u1ec1 b\u1ed9 nh\u1edb \u0111\u1ec7m, s\u1eed d\u1ee5ng c\u00e1c c\u00f4ng c\u1ee5 t\u1ef1 \u0111\u1ed9ng h\u00f3a \u0111\u1ec3 qu\u1ea3n l\u00fd c\u1ea5u h\u00ecnh DNS v\u00e0 theo d\u00f5i c\u1ea9n th\u1eadn t\u00ecnh tr\u1ea1ng c\u0169ng nh\u01b0 hi\u1ec7u su\u1ea5t c\u1ee7a m\u00e1y ch\u1ee7 DNS.<\/p>\n<h2>\u0110\u1eb7c \u0111i\u1ec3m ch\u00ednh v\u00e0 so s\u00e1nh<\/h2>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 so s\u00e1nh d\u1ef1 ph\u00f2ng DNS v\u1edbi c\u00e1c kh\u00e1i ni\u1ec7m t\u01b0\u01a1ng t\u1ef1:<\/p>\n<table>\n<thead>\n<tr>\n<th>\u00dd t\u01b0\u1edfng<\/th>\n<th>S\u1ef1 mi\u00eau t\u1ea3<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>C\u00e2n b\u1eb1ng t\u1ea3i<\/td>\n<td>C\u00e2n b\u1eb1ng t\u1ea3i li\u00ean quan \u0111\u1ebfn vi\u1ec7c ph\u00e2n ph\u1ed1i l\u01b0u l\u01b0\u1ee3ng m\u1ea1ng tr\u00ean nhi\u1ec1u m\u00e1y ch\u1ee7 \u0111\u1ec3 t\u1ed1i \u01b0u h\u00f3a vi\u1ec7c s\u1eed d\u1ee5ng t\u00e0i nguy\u00ean v\u00e0 ng\u0103n ng\u1eeba t\u00ecnh tr\u1ea1ng qu\u00e1 t\u1ea3i. D\u1ef1 ph\u00f2ng DNS c\u00f3 th\u1ec3 h\u1ed7 tr\u1ee3 c\u00e2n b\u1eb1ng t\u1ea3i b\u1eb1ng c\u00e1ch h\u01b0\u1edbng truy v\u1ea5n \u0111\u1ebfn c\u00e1c m\u00e1y ch\u1ee7 kh\u00e1c nhau.<\/td>\n<\/tr>\n<tr>\n<td>Chuy\u1ec3n \u0111\u1ed5i d\u1ef1 ph\u00f2ng<\/td>\n<td>Chuy\u1ec3n \u0111\u1ed5i d\u1ef1 ph\u00f2ng l\u00e0 qu\u00e1 tr\u00ecnh chuy\u1ec3n sang h\u1ec7 th\u1ed1ng d\u1ef1 ph\u00f2ng khi h\u1ec7 th\u1ed1ng ch\u00ednh b\u1ecb l\u1ed7i. D\u1ef1 ph\u00f2ng DNS c\u00f3 th\u1ec3 h\u1ed7 tr\u1ee3 chuy\u1ec3n \u0111\u1ed5i d\u1ef1 ph\u00f2ng b\u1eb1ng c\u00e1ch \u0111\u1ea3m b\u1ea3o r\u1eb1ng c\u00e1c m\u00e1y ch\u1ee7 DNS thay th\u1ebf c\u00f3 th\u1ec3 x\u1eed l\u00fd c\u00e1c y\u00eau c\u1ea7u khi m\u00e1y ch\u1ee7 ch\u00ednh kh\u00f4ng kh\u1ea3 d\u1ee5ng.<\/td>\n<\/tr>\n<tr>\n<td>T\u00ednh s\u1eb5n s\u00e0ng cao<\/td>\n<td>T\u00ednh s\u1eb5n s\u00e0ng cao t\u1eadp trung v\u00e0o vi\u1ec7c duy tr\u00ec th\u1eddi gian ho\u1ea1t \u0111\u1ed9ng d\u1ecbch v\u1ee5 li\u00ean t\u1ee5c. D\u1ef1 ph\u00f2ng DNS g\u00f3p ph\u1ea7n n\u00e2ng cao t\u00ednh s\u1eb5n s\u00e0ng b\u1eb1ng c\u00e1ch ph\u00e2n ph\u1ed1i d\u1ecbch v\u1ee5 DNS tr\u00ean c\u00e1c m\u00e1y ch\u1ee7 d\u1ef1 ph\u00f2ng, ng\u0103n ch\u1eb7n c\u00e1c \u0111i\u1ec3m l\u1ed7i \u0111\u01a1n l\u1ebb.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Quan \u0111i\u1ec3m v\u00e0 c\u00f4ng ngh\u1ec7 t\u01b0\u01a1ng lai<\/h2>\n<p>Nh\u00ecn v\u1ec1 ph\u00eda tr\u01b0\u1edbc, nh\u1eefng ti\u1ebfn b\u1ed9 trong c\u00f4ng ngh\u1ec7 DNS c\u00f3 th\u1ec3 s\u1ebd t\u0103ng c\u01b0\u1eddng h\u01a1n n\u1eefa kh\u1ea3 n\u0103ng d\u1ef1 ph\u00f2ng DNS. M\u1ed9t s\u1ed1 ph\u00e1t tri\u1ec3n ti\u1ec1m n\u0103ng trong t\u01b0\u01a1ng lai bao g\u1ed3m:<\/p>\n<ol>\n<li>\n<p><strong>DNS qua HTTPS (DoH) v\u00e0 DNS qua TLS (DoT):<\/strong> C\u00e1c giao th\u1ee9c DNS \u0111\u01b0\u1ee3c m\u00e3 h\u00f3a c\u00f3 th\u1ec3 c\u1ea3i thi\u1ec7n t\u00ednh b\u1ea3o m\u1eadt v\u00e0 quy\u1ec1n ri\u00eang t\u01b0 trong li\u00ean l\u1ea1c DNS, gi\u00fap vi\u1ec7c d\u1ef1 ph\u00f2ng DNS tr\u00ean c\u00e1c k\u00eanh b\u1ea3o m\u1eadt n\u00e0y tr\u1edf n\u00ean m\u1ea1nh m\u1ebd h\u01a1n.<\/p>\n<\/li>\n<li>\n<p><strong>\u00c1p d\u1ee5ng IPv6:<\/strong> Khi th\u1ebf gi\u1edbi chuy\u1ec3n sang IPv6, d\u1ef1 ph\u00f2ng DNS s\u1ebd c\u1ea7n h\u1ed7 tr\u1ee3 c\u00e1c b\u1ea3n ghi IPv6 v\u00e0 ph\u00e2n gi\u1ea3i \u0111\u1ecba ch\u1ec9.<\/p>\n<\/li>\n<li>\n<p><strong>DNS d\u1ef1a tr\u00ean chu\u1ed7i kh\u1ed1i:<\/strong> Th\u1eed nghi\u1ec7m v\u1edbi c\u00e1c h\u1ec7 th\u1ed1ng DNS d\u1ef1a tr\u00ean blockchain c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn ki\u1ebfn tr\u00fac DNS phi t\u1eadp trung, c\u00f3 t\u00ednh d\u01b0 th\u1eeba cao.<\/p>\n<\/li>\n<\/ol>\n<h2>D\u1ef1 ph\u00f2ng DNS v\u00e0 m\u00e1y ch\u1ee7 proxy<\/h2>\n<p>M\u00e1y ch\u1ee7 proxy \u0111\u00f3ng m\u1ed9t vai tr\u00f2 quan tr\u1ecdng trong b\u1ea3o m\u1eadt m\u1ea1ng, hi\u1ec7u su\u1ea5t v\u00e0 t\u00ednh \u1ea9n danh. Khi \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng c\u00f9ng v\u1edbi d\u1ef1 ph\u00f2ng DNS, m\u00e1y ch\u1ee7 proxy c\u00f3 th\u1ec3 n\u00e2ng cao h\u01a1n n\u1eefa \u0111\u1ed9 tin c\u1eady v\u00e0 kh\u1ea3 n\u0103ng ch\u1ecbu l\u1ed7i c\u1ee7a ch\u00fang. B\u1eb1ng c\u00e1ch h\u01b0\u1edbng c\u00e1c truy v\u1ea5n DNS qua nhi\u1ec1u m\u00e1y ch\u1ee7 DNS d\u1ef1 ph\u00f2ng tr\u01b0\u1edbc khi \u0111\u1ebfn m\u00e1y ch\u1ee7 proxy, c\u00e1c v\u1ea5n \u0111\u1ec1 ti\u1ec1m \u1ea9n li\u00ean quan \u0111\u1ebfn DNS s\u1ebd \u0111\u01b0\u1ee3c gi\u1ea3m thi\u1ec3u. Ngo\u00e0i ra, m\u00e1y ch\u1ee7 proxy c\u00f3 th\u1ec3 tri\u1ec3n khai c\u00e1c c\u01a1 ch\u1ebf d\u1ef1 ph\u00f2ng c\u1ee7a ri\u00eang ch\u00fang, ch\u1eb3ng h\u1ea1n nh\u01b0 c\u00e2n b\u1eb1ng t\u1ea3i v\u00e0 chuy\u1ec3n \u0111\u1ed5i d\u1ef1 ph\u00f2ng, \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o ho\u1ea1t \u0111\u1ed9ng tr\u01a1n tru.<\/p>\n<h2>Li\u00ean k\u1ebft li\u00ean quan<\/h2>\n<p>\u0110\u1ec3 bi\u1ebft th\u00eam th\u00f4ng tin v\u1ec1 d\u1ef1 ph\u00f2ng 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.cloudflare.com\/learning\/dns\/glossary\/dns-redundancy\/\" target=\"_new\" rel=\"noopener nofollow\">Gi\u1edbi thi\u1ec7u v\u1ec1 d\u1ef1 ph\u00f2ng DNS<\/a><\/li>\n<li><a href=\"https:\/\/tools.ietf.org\/html\/rfc1035\" target=\"_new\" rel=\"noopener nofollow\">RFC 1035 \u2013 T\u00ean mi\u1ec1n \u2013 Tri\u1ec3n khai v\u00e0 \u0111\u1eb7c t\u1ea3<\/a><\/li>\n<li><a href=\"https:\/\/www.apnic.net\/community\/security\/dnssec\/dns-resilience-and-redundancy\/\" target=\"_new\" rel=\"noopener nofollow\">Kh\u1ea3 n\u0103ng ph\u1ee5c h\u1ed3i v\u00e0 d\u1ef1 ph\u00f2ng DNS<\/a><\/li>\n<\/ul>\n<p>T\u00f3m l\u1ea1i, d\u1ef1 ph\u00f2ng DNS l\u00e0 m\u1ed9t kh\u00eda c\u1ea1nh quan tr\u1ecdng c\u1ee7a c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng internet hi\u1ec7n \u0111\u1ea1i, mang l\u1ea1i \u0111\u1ed9 tin c\u1eady, kh\u1ea3 n\u0103ng ch\u1ecbu l\u1ed7i v\u00e0 c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t. B\u1eb1ng c\u00e1ch hi\u1ec3u r\u00f5 l\u1ecbch s\u1eed, nguy\u00ean t\u1eafc ho\u1ea1t \u0111\u1ed9ng, lo\u1ea1i h\u00ecnh v\u00e0 ti\u1ec1m n\u0103ng ph\u00e1t tri\u1ec3n trong t\u01b0\u01a1ng lai, OneProxy c\u00f3 th\u1ec3 \u0111\u1ea3m b\u1ea3o cung c\u1ea5p d\u1ecbch v\u1ee5 m\u1ea1nh m\u1ebd v\u00e0 \u0111\u00e1ng tin c\u1eady cho ng\u01b0\u1eddi d\u00f9ng, n\u00e2ng cao tr\u1ea3i nghi\u1ec7m v\u00e0 s\u1ef1 h\u00e0i l\u00f2ng c\u1ee7a h\u1ecd.<\/p>","protected":false},"featured_media":476928,"menu_order":0,"template":"","meta":{"_acf_changed":false,"content-type":"","inline_featured_image":false,"footnotes":""},"class_list":["post-476927","wiki","type-wiki","status-publish","has-post-thumbnail","hentry"],"acf":{"faq_title":"Frequently Asked Questions about <mark>DNS Redundancy: Ensuring Resilience and Reliability<\/mark>","faq_items":[{"question":"What is DNS redundancy?","answer":"<p>DNS redundancy is a crucial aspect of internet infrastructure that involves deploying multiple redundant DNS servers. It ensures high availability and fault tolerance by distributing domain name resolution queries across these servers. This redundancy prevents service disruptions and improves overall performance.<\/p>"},{"question":"How did DNS redundancy originate?","answer":"<p>The concept of DNS redundancy emerged alongside the development of the Domain Name System (DNS) in the 1980s. It was first mentioned in RFC 882 in November 1983, highlighting the need for a distributed DNS system to mitigate single points of failure.<\/p>"},{"question":"How does DNS redundancy work?","answer":"<p>DNS redundancy works by setting up primary and secondary DNS servers. The primary server holds the master copy of the DNS zone data, while secondary servers regularly synchronize with it to stay up-to-date. When a DNS query is received, any of the redundant servers can respond, distributing the load and providing fault tolerance.<\/p>"},{"question":"What are the key features of DNS redundancy?","answer":"<p>The key features of DNS redundancy include high availability, load distribution, fault tolerance, geo-redundancy, and support for dynamic updates. These features ensure a stable and resilient DNS service.<\/p>"},{"question":"What types of DNS redundancy exist?","answer":"<p>There are several types of DNS redundancy, including:<\/p><ul><li>Primary-Secondary: One primary server with multiple secondary servers syncing with it.<\/li><li>Hidden Master: A non-public primary server replicating data to public-facing secondary servers.<\/li><li>Master-Master: Multiple primary servers with the ability to accept updates.<\/li><li>Anycast: Deploying identical DNS servers in different locations, directing queries to the nearest available server.<\/li><\/ul>"},{"question":"How is DNS redundancy used, and what challenges does it face?","answer":"<p>DNS redundancy is used to ensure continuous service availability. However, challenges such as synchronization delays and DNS cache consistency may arise. To address these, shorter TTL values and automation tools can be employed.<\/p>"},{"question":"How does DNS redundancy compare to load balancing and failover?","answer":"<p>DNS redundancy complements load balancing and failover mechanisms. While load balancing distributes network traffic across servers, DNS redundancy ensures redundancy in DNS resolution. Failover switches to redundant systems when the primary fails, and DNS redundancy supports this by providing alternate servers to handle queries.<\/p>"},{"question":"What are the future technologies related to DNS redundancy?","answer":"<p>Future technologies may include DNS over HTTPS (DoH) and DNS over TLS (DoT) for encrypted DNS communications, IPv6 support, and exploration of blockchain-based DNS systems for decentralized redundancy.<\/p>"},{"question":"How can proxy servers benefit from DNS redundancy?","answer":"<p>Proxy servers can enhance their reliability and performance by leveraging DNS redundancy. Integrating redundant DNS servers before reaching the proxy ensures minimized DNS-related issues, while proxy servers themselves can implement load balancing and failover mechanisms for added reliability.<\/p>"},{"question":"Where can I find more information about DNS redundancy?","answer":"<p>For more in-depth information about DNS redundancy, you can explore the following resources:<\/p><ul><li><a href=\"https:\/\/www.cloudflare.com\/learning\/dns\/glossary\/dns-redundancy\/\" target=\"_new\">Introduction to DNS Redundancy<\/a><\/li><li><a href=\"https:\/\/tools.ietf.org\/html\/rfc1035\" target=\"_new\">RFC 1035 - Domain Names - Implementation and Specification<\/a><\/li><li><a href=\"https:\/\/www.apnic.net\/community\/security\/dnssec\/dns-resilience-and-redundancy\/\" target=\"_new\">DNS Resilience and Redundancy<\/a><\/li><\/ul>"}]},"_links":{"self":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/wiki\/476927","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\/476927\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/media\/476928"}],"wp:attachment":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/media?parent=476927"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}