{"id":88761,"date":"2025-07-01T08:55:36","date_gmt":"2025-07-01T01:55:36","guid":{"rendered":"https:\/\/itviec.com\/blog\/?p=88761"},"modified":"2025-07-01T08:55:39","modified_gmt":"2025-07-01T01:55:39","slug":"cau-hoi-phong-van-network-engineer","status":"publish","type":"post","link":"https:\/\/itviec.com\/blog\/cau-hoi-phong-van-network-engineer\/","title":{"rendered":"Top 30+ c\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer ph\u1ed5 bi\u1ebfn"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">N\u1ed9i dung b\u00e0i vi\u1ebft<\/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 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/itviec.com\/blog\/cau-hoi-phong-van-network-engineer\/#Ung_vien_can_chuan_bi_gi_cho_buoi_phong_van_Network_Engineer\" >\u1ee8ng vi\u00ean c\u1ea7n chu\u1ea9n b\u1ecb g\u00ec cho bu\u1ed5i ph\u1ecfng v\u1ea5n Network Engineer?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/itviec.com\/blog\/cau-hoi-phong-van-network-engineer\/#Cau_hoi_phong_van_Network_Engineer_co_ban\" >C\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer c\u01a1 b\u1ea3n<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/itviec.com\/blog\/cau-hoi-phong-van-network-engineer\/#Cau_hoi_phong_van_Network_Engineer_trung_cap\" >C\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer trung c\u1ea5p<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/itviec.com\/blog\/cau-hoi-phong-van-network-engineer\/#Cau_hoi_phong_van_Network_Engineer_cap_cao\" >C\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer c\u1ea5p cao<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/itviec.com\/blog\/cau-hoi-phong-van-network-engineer\/#21_Lam_the_nao_de_dam_bao_an_ninh_mang_trong_khi_van_duy_tri_hieu_suat\" >21. L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o an ninh m\u1ea1ng trong khi v\u1eabn duy tr\u00ec hi\u1ec7u su\u1ea5t?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/itviec.com\/blog\/cau-hoi-phong-van-network-engineer\/#Tong_ket\" >T\u1ed5ng k\u1ebft<\/a><\/li><\/ul><\/nav><\/div>\n\n<p><strong><em>B\u1ea1n \u0111ang chu\u1ea9n b\u1ecb b\u01b0\u1edbc v\u00e0o v\u00f2ng ph\u1ecfng v\u1ea5n cho v\u1ecb tr\u00ed Network Engineer? B\u00e0i vi\u1ebft n\u00e0y s\u1ebd gi\u00fap b\u1ea1n t\u1ed5ng h\u1ee3p nh\u1eefng c\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer ph\u1ed5 bi\u1ebfn nh\u1ea5t, \u0111i k\u00e8m v\u1edbi g\u1ee3i \u00fd c\u00e1ch tr\u1ea3 l\u1eddi th\u00f4ng minh v\u00e0 hi\u1ec7u qu\u1ea3. C\u00f9ng kh\u00e1m ph\u00e1 nh\u1eefng c\u00e2u h\u1ecfi ph\u1ed5 bi\u1ebfn nh\u1ea5t v\u00e0 chi\u1ebfn l\u01b0\u1ee3c tr\u1ea3 l\u1eddi gi\u00fap b\u1ea1n n\u1ed5i b\u1eadt trong m\u1eaft nh\u00e0 tuy\u1ec3n d\u1ee5ng.<\/em><\/strong><\/p>\n\n\n\n<p>\u0110\u1ecdc b\u00e0i vi\u1ebft n\u00e0y \u0111\u1ec3 n\u1eafm r\u00f5:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Checklist ki\u1ebfn th\u1ee9c c\u1ea7n chu\u1ea9n b\u1ecb tr\u01b0\u1edbc bu\u1ed5i ph\u1ecfng v\u1ea5n;<\/li>\n\n\n\n<li>C\u00e1ch tr\u1ea3 l\u1eddi c\u00e1c c\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer c\u01a1 b\u1ea3n;<\/li>\n\n\n\n<li>C\u00e1ch tr\u1ea3 l\u1eddi c\u00e1c c\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer c\u1ea5p trung;<\/li>\n\n\n\n<li>C\u00e1ch tr\u1ea3 l\u1eddi c\u00e1c c\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer c\u1ea5p cao.<\/li>\n<\/ul>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><em>\u0110\u1ecdc th\u00eam: <strong><a href=\"https:\/\/itviec.com\/blog\/network-engineer-roadmap\/\" target=\"_blank\" rel=\"noreferrer noopener\">Network Engineer Roadmap: L\u1ed9 tr\u00ecnh t\u1eeb k\u1ef9 n\u0103ng \u0111\u1ebfn ch\u1ee9ng ch\u1ec9<\/a><\/strong><\/em><\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-\u1ee9ng-vien-c\u1ea7n-chu\u1ea9n-b\u1ecb-gi-cho-bu\u1ed5i-ph\u1ecfng-v\u1ea5n-network-engineer\"><span class=\"ez-toc-section\" id=\"Ung_vien_can_chuan_bi_gi_cho_buoi_phong_van_Network_Engineer\"><\/span><strong>\u1ee8ng vi\u00ean c\u1ea7n chu\u1ea9n b\u1ecb g\u00ec cho bu\u1ed5i ph\u1ecfng v\u1ea5n Network Engineer?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>C\u00e1c v\u1ea5n \u0111\u1ec1 ch\u00ednh m\u00e0 \u1ee9ng vi\u00ean <strong><a href=\"https:\/\/itviec.com\/blog\/network-engineer-la-gi\/\" target=\"_blank\" rel=\"noreferrer noopener\">Network Engineer<\/a><\/strong> c\u00f3 th\u1ec3 chu\u1ea9n b\u1ecb bao g\u1ed3m:<\/p>\n\n\n\n<p><strong>Ki\u1ebfn th\u1ee9c m\u1ea1ng c\u01a1 b\u1ea3n:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>M\u00f4 h\u00ecnh OSI: Hi\u1ec3u c\u00e1c layer v\u00e0 ch\u1ee9c n\u0103ng c\u1ee7a ch\u00fang, c\u0169ng nh\u01b0 m\u1ee9c \u0111\u1ed9 li\u00ean quan \u0111\u1ebfn m\u1ea1ng.<\/li>\n\n\n\n<li>\u0110\u1ecba ch\u1ec9 IP v\u00e0 m\u1ea1ng con: Bi\u1ebft c\u00e1ch t\u00ednh to\u00e1n subnet mask v\u00e0 \u0111\u1ecba ch\u1ec9, c\u0169ng nh\u01b0 c\u00e1c l\u1edbp \u0111\u1ecba ch\u1ec9 IP kh\u00e1c nhau.<\/li>\n\n\n\n<li>Giao th\u1ee9c \u0111\u1ecbnh tuy\u1ebfn: OSPF, EIGRP v\u00e0 BGP, \u0111\u1ed3ng th\u1eddi b\u1ed5 sung ki\u1ebfn th\u1ee9c v\u1ec1 c\u00e1c c\u00f4ng c\u1ee5 qu\u1ea3n l\u00fd m\u1ea1ng kh\u00e1c nh\u01b0 PRTG, Nagios, Zabbix, Cisco Prime v\u00e0 Netflow Analyzer.<\/li>\n\n\n\n<li>Thi\u1ebft b\u1ecb m\u1ea1ng: Hi\u1ec3u s\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa c\u00e1c b\u1ed9 chuy\u1ec3n m\u1ea1ch, b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn, firewall v\u00e0 load balancer.<\/li>\n\n\n\n<li>Network Protocol: Bi\u1ebft TCP, UDP, HTTP, DNS, DHCP v\u00e0 c\u00e1c protocol ph\u1ed5 bi\u1ebfn kh\u00e1c.<\/li>\n<\/ul>\n\n\n\n<p><strong>B\u1ea3o m\u1eadt m\u1ea1ng:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Firewall: Hi\u1ec3u ch\u1ee9c n\u0103ng v\u00e0 c\u00e1ch c\u1ea5u h\u00ecnh firewall.<\/li>\n\n\n\n<li>VPN: Hi\u1ec3u c\u00e1c lo\u1ea1i VPN kh\u00e1c nhau v\u00e0 c\u00e1ch ch\u00fang ho\u1ea1t \u0111\u1ed9ng.<\/li>\n\n\n\n<li>C\u00e1c m\u1ed1i \u0111e d\u1ecda b\u1ea3o m\u1eadt m\u1ea1ng: Nh\u1eadn bi\u1ebft c\u00e1c m\u1ed1i \u0111e d\u1ecda ph\u1ed5 bi\u1ebfn v\u00e0 c\u00e1ch gi\u1ea3m thi\u1ec3u ch\u00fang.<\/li>\n<\/ul>\n\n\n\n<p><strong>X\u1eed l\u00fd s\u1ef1 c\u1ed1:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>C\u00e1c b\u01b0\u1edbc x\u1eed l\u00fd s\u1ef1 c\u1ed1 c\u01a1 b\u1ea3n: N\u1eafm r\u00f5 c\u00e1c b\u01b0\u1edbc x\u1eed l\u00fd s\u1ef1 c\u1ed1 ph\u1ed5 bi\u1ebfn, ch\u1eb3ng h\u1ea1n nh\u01b0 s\u1eed d\u1ee5ng ping, tracert v\u00e0 netstat.<\/li>\n\n\n\n<li>C\u00e1c s\u1ef1 c\u1ed1 m\u1ea1ng ph\u1ed5 bi\u1ebfn: N\u1eafm \u0111\u01b0\u1ee3c c\u00e1c s\u1ef1 c\u1ed1 ph\u1ed5 bi\u1ebfn nh\u01b0 s\u1ef1 c\u1ed1 k\u1ebft n\u1ed1i m\u1ea1ng, s\u1ef1 c\u1ed1 gi\u1ea3i quy\u1ebft DNS v\u00e0 t\u00ecnh tr\u1ea1ng t\u1eafc ngh\u1ebdn hi\u1ec7u su\u1ea5t.<\/li>\n<\/ul>\n\n\n\n<p><strong>K\u1ef9 n\u0103ng th\u1ef1c h\u00e0nh:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Thi\u1ebft k\u1ebf v\u00e0 ki\u1ebfn \u200b\u200btr\u00fac m\u1ea1ng: Hi\u1ec3u c\u00e1c lo\u1ea1i c\u1ea5u tr\u00fac m\u1ea1ng kh\u00e1c nhau v\u00e0 c\u00e1ch thi\u1ebft k\u1ebf m\u1ea1ng cho c\u00e1c nhu c\u1ea7u c\u1ee5 th\u1ec3.<\/li>\n\n\n\n<li>Gi\u00e1m s\u00e1t v\u00e0 qu\u1ea3n l\u00fd m\u1ea1ng: L\u00e0m quen v\u1edbi c\u00e1c c\u00f4ng c\u1ee5 nh\u01b0 Wireshark v\u00e0 SolarWinds.<\/li>\n\n\n\n<li>T\u1ef1 \u0111\u1ed9ng h\u00f3a m\u1ea1ng: Hi\u1ec3u nh\u1eefng \u0111i\u1ec1u c\u01a1 b\u1ea3n v\u1ec1 t\u1ef1 \u0111\u1ed9ng h\u00f3a m\u1ea1ng v\u00e0 l\u1eadp tr\u00ecnh.<\/li>\n\n\n\n<li>M\u1ea1ng \u0111\u00e1m m\u00e2y: Hi\u1ec3u nh\u1eefng \u0111i\u1ec1u c\u01a1 b\u1ea3n v\u1ec1 m\u1ea1ng \u0111\u00e1m m\u00e2y v\u00e0 m\u1ea1ng \u1ea3o.<\/li>\n<\/ul>\n\n\n\n<p>Ng\u01b0\u1eddi ph\u1ecfng v\u1ea5n th\u01b0\u1eddng \u0111\u01b0a ra c\u00e1c t\u00ecnh hu\u1ed1ng \u0111\u1ec3 \u0111\u00e1nh gi\u00e1 k\u1ef9 n\u0103ng ph\u00e2n t\u00edch v\u00e0 c\u00e1ch ti\u1ebfp c\u1eadn c\u1ee7a b\u1ea1n \u0111\u1ed1i v\u1edbi vi\u1ec7c kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1. H\u00e3y s\u1eb5n s\u00e0ng gi\u1ea3i quy\u1ebft c\u00e1c c\u00e2u h\u1ecfi gi\u1ea3i quy\u1ebft v\u1ea5n \u0111\u1ec1, ti\u1ebfn h\u00e0nh ph\u1ecfng v\u1ea5n th\u1eed v\u00e0 xem x\u00e9t c\u00e1c c\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p d\u01b0\u1edbi \u0111\u00e2y:<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-cau-h\u1ecfi-ph\u1ecfng-v\u1ea5n-network-engineer-c\u01a1-b\u1ea3n\"><span class=\"ez-toc-section\" id=\"Cau_hoi_phong_van_Network_Engineer_co_ban\"><\/span><strong>C\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer c\u01a1 b\u1ea3n<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-1-m\u1ea1ng-point-to-point-la-gi\"><strong>1. M\u1ea1ng point-to-point l\u00e0 g\u00ec?<\/strong><\/h3>\n\n\n\n<p>M\u1ea1ng point-to-point (P2P), l\u00e0 k\u1ebft n\u1ed1i v\u1eadt l\u00fd gi\u1eefa hai node, l\u00e0 b\u1ea5t k\u1ef3 thi\u1ebft b\u1ecb \u0111i\u1ec7n t\u1eed n\u00e0o tr\u00ean m\u1ea1ng, ch\u1eb3ng h\u1ea1n nh\u01b0 m\u00e1y in, m\u00e1y t\u00ednh kh\u00e1c ho\u1eb7c m\u00e1y ch\u1ee7. M\u1ea1ng P2P l\u00e0 m\u1ea1ng kh\u00e9p k\u00edn ri\u00eang t\u01b0, c\u00f3 th\u1ec3 truy\u1ec1n d\u1eef li\u1ec7u m\u1ed9t c\u00e1ch an to\u00e0n, th\u01b0\u1eddng kh\u00f4ng c\u1ea7n m\u00e3 h\u00f3a.&nbsp;<\/p>\n\n\n\n<p>K\u1ebft n\u1ed1i P2P c\u00f3 th\u1ec3 c\u00f3 t\u1ed1c \u0111\u1ed9 b\u0103ng th\u00f4ng kh\u00e1c nhau v\u00e0 cung c\u1ea5p ch\u1ea5t l\u01b0\u1ee3ng d\u1ecbch v\u1ee5 v\u00f4 song. \u0110i\u1ec1u n\u00e0y ch\u1ee7 y\u1ebfu l\u00e0 do k\u1ebft n\u1ed1i ri\u00eang t\u01b0 c\u1ee7a n\u00f3 v\u00e0 v\u00ec P2P truy\u1ec1n d\u1eef li\u1ec7u d\u1ecdc theo c\u00f9ng m\u1ed9t \u0111\u01b0\u1eddng d\u1eabn m\u1ea1ng an to\u00e0n v\u00e0 tr\u1ef1c ti\u1ebfp.&nbsp;<\/p>\n\n\n\n<p>C\u00e1c \u1ee9ng d\u1ee5ng ph\u1ed5 bi\u1ebfn c\u1ee7a m\u1ea1ng P2P bao g\u1ed3m \u0111\u01b0\u1eddng truy\u1ec1n T1\/E1, k\u1ebft n\u1ed1i PPP qua Serial, c\u00e1c \u0111\u01b0\u1eddng k\u1ebft n\u1ed1i MPLS v\u00e0 k\u1ebft n\u1ed1i leased line trong m\u00f4i tr\u01b0\u1eddng doanh nghi\u1ec7p.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-2-d\u1ecba-ch\u1ec9-ipv4-la-gi-co-nh\u1eefng-ipv4-class-nao\"><strong>2. \u0110\u1ecba ch\u1ec9 IPv4 l\u00e0 g\u00ec? C\u00f3 nh\u1eefng IPv4 class n\u00e0o?<\/strong><\/h3>\n\n\n\n<p>\u0110\u1ecba ch\u1ec9 IP l\u00e0 \u0111\u1ecba ch\u1ec9 32-bit dynamic c\u1ee7a m\u1ed9t node trong m\u1ea1ng. \u0110\u1ecba ch\u1ec9 IPv4 c\u00f3 4 octet, m\u1ed7i octet 8 bit, m\u1ed7i s\u1ed1 c\u00f3 gi\u00e1 tr\u1ecb l\u00ean \u0111\u1ebfn 255. C\u00e1c IPv4 class \u0111\u01b0\u1ee3c ph\u00e2n bi\u1ec7t d\u1ef1a tr\u00ean s\u1ed1 l\u01b0\u1ee3ng m\u00e1y ch\u1ee7 m\u00e0 n\u00f3 h\u1ed7 tr\u1ee3 tr\u00ean m\u1ea1ng. C\u00f3 5 lo\u1ea1i IPv4 class v\u00e0 d\u1ef1a tr\u00ean octet \u0111\u1ea7u ti\u00ean c\u1ee7a \u0111\u1ecba ch\u1ec9 IP \u0111\u01b0\u1ee3c ph\u00e2n lo\u1ea1i l\u00e0 A, B, C, D ho\u1eb7c E.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>IPv4 class<\/strong><\/td><td><strong>IPv4 Start Address<\/strong><\/td><td><strong>IPv4 End Address<\/strong><\/td><td><strong>C\u00e1ch s\u1eed d\u1ee5ng<\/strong><\/td><\/tr><tr><td>A<\/td><td>0.0.0.0<\/td><td>127.255.255.255<\/td><td>S\u1eed d\u1ee5ng cho m\u1ea1ng l\u1edbn<\/td><\/tr><tr><td>B<\/td><td>128.0.0.0<\/td><td>191.255.255.255<\/td><td>S\u1eed d\u1ee5ng cho m\u1ea1ng c\u1ee1 trung b\u00ecnh<\/td><\/tr><tr><td>C<\/td><td>192.0.0.0<\/td><td>223.255.255.255<\/td><td>S\u1eed d\u1ee5ng cho m\u1ea1ng c\u1ee5c b\u1ed9<\/td><\/tr><tr><td>D<\/td><td>224.0.0.0<\/td><td>239.255.255.255<\/td><td>D\u00e0nh ri\u00eang cho Multicasting<\/td><\/tr><tr><td>E<\/td><td>240.0.0.0<\/td><td>255.255.255.254<\/td><td>Nghi\u00ean c\u1ee9u v\u00e0 R&amp;D<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>Hi\u1ec7n nay, ph\u00e2n lo\u1ea1i IP theo class \u0111\u00e3 \u00edt \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong th\u1ef1c t\u1ebf. Thay v\u00e0o \u0111\u00f3, CIDR (Classless Inter-Domain Routing) \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng ph\u1ed5 bi\u1ebfn h\u01a1n nh\u1eb1m ph\u00e2n ph\u1ed1i \u0111\u1ecba ch\u1ec9 IP m\u1ed9t c\u00e1ch linh ho\u1ea1t v\u00e0 hi\u1ec7u qu\u1ea3 h\u01a1n. CIDR s\u1eed d\u1ee5ng k\u00fd hi\u1ec7u ti\u1ec1n t\u1ed1 (prefix notation) nh\u01b0 192.168.1.0\/24 \u0111\u1ec3 ch\u1ec9 ra s\u1ed1 l\u01b0\u1ee3ng bit d\u00e0nh cho ph\u1ea7n m\u1ea1ng.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-3-mo-hinh-osi-la-gi-mo-t\u1ea3-cac-layer-c\u1ee7a-no\"><strong>3. M\u00f4 h\u00ecnh OSI l\u00e0 g\u00ec? M\u00f4 t\u1ea3 c\u00e1c layer c\u1ee7a n\u00f3?<\/strong><\/h3>\n\n\n\n<p>Open System Interconnections (OSI) l\u00e0 m\u1ed9t m\u00f4 h\u00ecnh ki\u1ebfn \u200b\u200btr\u00fac m\u1ea1ng d\u1ef1a tr\u00ean c\u00e1c ti\u00eau chu\u1ea9n ISO. \u0110\u01b0\u1ee3c g\u1ecdi l\u00e0 m\u00f4 h\u00ecnh OSI v\u00ec n\u00f3 x\u1eed l\u00fd vi\u1ec7c k\u1ebft n\u1ed1i c\u00e1c h\u1ec7 th\u1ed1ng m\u1edf \u0111\u1ec3 giao ti\u1ebfp v\u1edbi c\u00e1c h\u1ec7 th\u1ed1ng kh\u00e1c. M\u00f4 h\u00ecnh OSI c\u00f3 7 layer:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Physical: Truy\u1ec1n c\u00e1c bit d\u1eef li\u1ec7u th\u00f4 qua ph\u01b0\u01a1ng ti\u1ec7n v\u1eadt l\u00fd. C\u00e1c thi\u1ebft b\u1ecb \u1edf layer n\u00e0y bao g\u1ed3m hub, repeater, c\u00e1p, connector. C\u00e1c ti\u00eau chu\u1ea9n ph\u1ed5 bi\u1ebfn bao g\u1ed3m RS-232, V.35, RJ45.<\/li>\n\n\n\n<li>Data Link: Cung c\u1ea5p kh\u1ea3 n\u0103ng truy\u1ec1n d\u1eef li\u1ec7u gi\u1eefa c\u00e1c node v\u00e0 x\u1eed l\u00fd l\u1ed7i.\u00a0<\/li>\n\n\n\n<li>Network: Qu\u1ea3n l\u00fd \u0111\u1ecbnh tuy\u1ebfn v\u00e0 \u0111\u1ecba ch\u1ec9 (v\u00ed d\u1ee5: IP).<\/li>\n\n\n\n<li>Transport: \u0110\u1ea3m b\u1ea3o truy\u1ec1n d\u1eef li\u1ec7u \u0111\u00e1ng tin c\u1eady (v\u00ed d\u1ee5: TCP, UDP)<\/li>\n\n\n\n<li>Session: Qu\u1ea3n l\u00fd c\u00e1c phi\u00ean gi\u1eefa c\u00e1c \u1ee9ng d\u1ee5ng. Ch\u1ecbu tr\u00e1ch nhi\u1ec7m thi\u1ebft l\u1eadp, duy tr\u00ec v\u00e0 k\u1ebft th\u00fac c\u00e1c phi\u00ean giao ti\u1ebfp. C\u00e1c giao th\u1ee9c bao g\u1ed3m NetBIOS, RPC, PPTP.<\/li>\n\n\n\n<li>Presentation: D\u1ecbch \u0111\u1ecbnh d\u1ea1ng d\u1eef li\u1ec7u v\u00e0 m\u00e3 h\u00f3a\/gi\u1ea3i m\u00e3. X\u1eed l\u00fd m\u00e3 h\u00f3a, n\u00e9n v\u00e0 chuy\u1ec3n \u0111\u1ed5i d\u1eef li\u1ec7u. C\u00e1c \u0111\u1ecbnh d\u1ea1ng v\u00e0 ti\u00eau chu\u1ea9n bao g\u1ed3m JPEG, MPEG, SSL\/TLS.<\/li>\n\n\n\n<li>Application: Giao di\u1ec7n tr\u1ef1c ti\u1ebfp v\u1edbi c\u00e1c \u1ee9ng d\u1ee5ng c\u1ee7a ng\u01b0\u1eddi d\u00f9ng. C\u00e1c giao th\u1ee9c bao g\u1ed3m HTTP, FTP, SMTP, DNS, Telnet, SSH, SNMP.<\/li>\n<\/ul>\n\n\n\n<p>Nguy\u00ean t\u1eafc \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 \u0111\u1ea1t \u0111\u01b0\u1ee3c 7 layer:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>T\u1ea1o m\u1ed9t layer m\u1edbi n\u1ebfu c\u1ea7n abstraction kh\u00e1c.<\/li>\n\n\n\n<li>M\u1ed7i layer ph\u1ea3i c\u00f3 ch\u1ee9c n\u0103ng \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh r\u00f5 r\u00e0ng.<\/li>\n\n\n\n<li>Ch\u1ee9c n\u0103ng c\u1ee7a m\u1ed7i layer \u0111\u01b0\u1ee3c l\u1ef1a ch\u1ecdn d\u1ef1a tr\u00ean c\u00e1c giao th\u1ee9c chu\u1ea9n h\u00f3a qu\u1ed1c t\u1ebf.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-4-gi\u1ea3i-thich-cach-ap-d\u1ee5ng-mo-hinh-osi-vao-vi\u1ec7c-kh\u1eafc-ph\u1ee5c-s\u1ef1-c\u1ed1-m\u1ea1ng\"><strong>4. Gi\u1ea3i th\u00edch c\u00e1ch \u00e1p d\u1ee5ng m\u00f4 h\u00ecnh OSI v\u00e0o vi\u1ec7c kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 m\u1ea1ng.<\/strong><\/h3>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>L\u01b0u \u00fd: Sau \u0111\u00e2y l\u00e0 v\u00ed d\u1ee5 v\u1ec1 m\u1eabu c\u00e2u tr\u1ea3 l\u1eddi m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o, h\u00e3y tr\u1ea3 l\u1eddi theo kinh nghi\u1ec7m c\u00e1 nh\u00e2n.<\/p>\n<\/blockquote>\n\n\n\n<p>M\u00f4 h\u00ecnh OSI bao g\u1ed3m 7 layer: Physical, Data Link, Network, Transport, Session, Presentation, Application. N\u1ebfu ch\u00fang ta g\u1eb7p s\u1ef1 c\u1ed1 k\u1ebft n\u1ed1i, tr\u01b0\u1edbc ti\u00ean t\u00f4i s\u1ebd ki\u1ec3m tra Physical layer \u0111\u1ec3 t\u00ecm s\u1ef1 c\u1ed1 ph\u1ea7n c\u1ee9ng, ch\u1eb3ng h\u1ea1n nh\u01b0 c\u00e1p b\u1ecb l\u1ed7i. N\u1ebfu \u1ed5n, t\u00f4i s\u1ebd xem Data Link layer \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o \u0111\u1ecba ch\u1ec9 MAC l\u00e0 ch\u00ednh x\u00e1c. Hi\u1ec3u m\u00f4 h\u00ecnh n\u00e0y gi\u00fap c\u00f4 l\u1eadp c\u00e1c s\u1ef1 c\u1ed1 m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3. Trong th\u1eddi gian th\u1ef1c t\u1eadp, t\u00f4i \u0111\u00e3 \u00e1p d\u1ee5ng m\u00f4 h\u00ecnh OSI \u0111\u1ec3 kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 m\u1ea5t m\u1ea1ng, d\u1eabn \u0111\u1ebfn vi\u1ec7c s\u1eeda b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn \u0111\u01b0\u1ee3c \u0111\u1ecbnh c\u1ea5u h\u00ecnh sai \u1edf Network layer.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-5-gi\u1ea3i-thich-cac-khai-ni\u1ec7m-nat-pan-man-gan-va-wan\"><strong>5. Gi\u1ea3i th\u00edch c\u00e1c kh\u00e1i ni\u1ec7m NAT, PAN, MAN, GAN v\u00e0 WAN?<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>NAT<\/strong> vi\u1ebft t\u1eaft c\u1ee7a Network Address Translation. \u0110\u00e2y l\u00e0 m\u1ed9t giao th\u1ee9c cung c\u1ea5p m\u1ed9t c\u00e1ch \u0111\u1ec3 nhi\u1ec1u m\u00e1y t\u00ednh tr\u00ean m\u1ed9t m\u1ea1ng chung chia s\u1ebb m\u1ed9t k\u1ebft n\u1ed1i duy nh\u1ea5t t\u1edbi Internet.<\/li>\n\n\n\n<li><strong>WAN<\/strong> vi\u1ebft t\u1eaft c\u1ee7a Wide Area Network. \u0110\u00e2y l\u00e0 s\u1ef1 k\u1ebft n\u1ed1i gi\u1eefa c\u00e1c m\u00e1y t\u00ednh v\u00e0 thi\u1ebft b\u1ecb \u0111\u01b0\u1ee3c ph\u00e2n t\u00e1n v\u1ec1 m\u1eb7t \u0111\u1ecba l\u00fd. N\u00f3 k\u1ebft n\u1ed1i c\u00e1c m\u1ea1ng n\u1eb1m \u1edf c\u00e1c khu v\u1ef1c v\u00e0 qu\u1ed1c gia kh\u00e1c nhau.<\/li>\n\n\n\n<li><strong>PAN<\/strong> vi\u1ebft t\u1eaft c\u1ee7a Personal Area Network cho ph\u00e9p c\u00e1c thi\u1ebft b\u1ecb k\u1ebft n\u1ed1i v\u00e0 giao ti\u1ebfp trong ph\u1ea1m vi c\u1ee7a m\u1ed9t ng\u01b0\u1eddi. V\u00ed d\u1ee5 k\u1ebft n\u1ed1i c\u00e1c thi\u1ebft b\u1ecb Bluetooth.<\/li>\n\n\n\n<li><strong>MAN<\/strong> vi\u1ebft t\u1eaft c\u1ee7a Metropolitan Area Network k\u1ebft n\u1ed1i v\u00e0 ph\u1ee7 s\u00f3ng to\u00e0n b\u1ed9 th\u00e0nh ph\u1ed1. V\u00ed d\u1ee5: K\u1ebft n\u1ed1i c\u00e1p truy\u1ec1n h\u00ecnh qua th\u00e0nh ph\u1ed1.<\/li>\n\n\n\n<li><strong>GAN<\/strong> vi\u1ebft t\u1eaft t\u1eeb Global Area Network, c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 Internet, k\u1ebft n\u1ed1i to\u00e0n c\u1ea7u b\u1eb1ng v\u1ec7 tinh. Internet c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 M\u1ea1ng WAN.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-6-gi\u1ea3i-thich-s\u1ef1-khac-bi\u1ec7t-gi\u1eefa-ipv4-va-ipv6\"><strong>6. Gi\u1ea3i th\u00edch s\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa IPv4 v\u00e0 IPv6.<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>IPv4: S\u1eed d\u1ee5ng \u0111\u1ecba ch\u1ec9 32 bit (v\u00ed d\u1ee5: 192.168.1.1), cung c\u1ea5p kho\u1ea3ng 4,3 t\u1ef7 \u0111\u1ecba ch\u1ec9.<\/li>\n\n\n\n<li>IPv6: S\u1eed d\u1ee5ng \u0111\u1ecba ch\u1ec9 128 bit (v\u00ed d\u1ee5: 2001:0db8:85a3:0000:0000:8a2e:0370:7334), cung c\u1ea5p kh\u00f4ng gian \u0111\u1ecba ch\u1ec9 l\u1edbn h\u01a1n r\u1ea5t nhi\u1ec1u.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-7-gi\u1ea3i-thich-v\u1ec1-lan-m\u1ea1ng-c\u1ee5c-b\u1ed9\"><strong>7. Gi\u1ea3i th\u00edch v\u1ec1 LAN (M\u1ea1ng c\u1ee5c b\u1ed9).<\/strong><\/h3>\n\n\n\n<p>LAN \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i \u0111\u1ec3 k\u1ebft n\u1ed1i m\u00e1y t\u00ednh\/m\u00e1y t\u00ednh x\u00e1ch tay v\u00e0 thi\u1ebft b\u1ecb \u0111i\u1ec7n t\u1eed ti\u00eau d\u00f9ng, cho ph\u00e9p ch\u00fang chia s\u1ebb t\u00e0i nguy\u00ean (v\u00ed d\u1ee5: m\u00e1y in, m\u00e1y fax) v\u00e0 trao \u0111\u1ed5i th\u00f4ng tin. Khi LAN \u0111\u01b0\u1ee3c c\u00e1c c\u00f4ng ty ho\u1eb7c t\u1ed5 ch\u1ee9c s\u1eed d\u1ee5ng, ch\u00fang \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 m\u1ea1ng doanh nghi\u1ec7p.&nbsp;<\/p>\n\n\n\n<p>C\u00f3 2 lo\u1ea1i m\u1ea1ng LAN kh\u00e1c nhau: LAN kh\u00f4ng d\u00e2y (kh\u00f4ng c\u1ea7n d\u00e2y, s\u1eed d\u1ee5ng Wi-Fi) v\u00e0 LAN c\u00f3 d\u00e2y (s\u1eed d\u1ee5ng c\u00e1p LAN). LAN kh\u00f4ng d\u00e2y r\u1ea5t ph\u1ed5 bi\u1ebfn hi\u1ec7n nay \u1edf nh\u1eefng n\u01a1i kh\u00f3 l\u1eafp d\u00e2y.&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-8-gi\u1ea3i-thich-khai-ni\u1ec7m-vpn-co-nh\u1eefng-lo\u1ea1i-vpn-nao-nbsp\"><strong>8. Gi\u1ea3i th\u00edch kh\u00e1i ni\u1ec7m VPN. C\u00f3 nh\u1eefng lo\u1ea1i VPN n\u00e0o?<\/strong>&nbsp;<\/h3>\n\n\n\n<p>VPN \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng tr\u00ean internet, cho ph\u00e9p t\u1ea1o tunnel b\u1ea3o m\u1eadt gi\u1eefa c\u00e1c m\u1ea1ng kh\u00e1c nhau b\u1eb1ng internet. B\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng VPN, m\u00e1y kh\u00e1ch c\u00f3 th\u1ec3 k\u1ebft n\u1ed1i t\u1eeb xa v\u1edbi m\u1ea1ng c\u1ee7a t\u1ed5 ch\u1ee9c. M\u1ed9t s\u1ed1 l\u1ee3i \u00edch khi s\u1eed d\u1ee5ng VPN:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>VPN \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 k\u1ebft n\u1ed1i c\u00e1c v\u0103n ph\u00f2ng \u1edf nhi\u1ec1u v\u1ecb tr\u00ed \u0111\u1ecba l\u00fd kh\u00e1c nhau t\u1eeb xa v\u00e0 r\u1ebb h\u01a1n so v\u1edbi k\u1ebft n\u1ed1i WAN.<\/li>\n\n\n\n<li>VPN \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 th\u1ef1c hi\u1ec7n c\u00e1c giao d\u1ecbch an to\u00e0n v\u00e0 truy\u1ec1n d\u1eef li\u1ec7u b\u00ed m\u1eadt gi\u1eefa nhi\u1ec1u v\u0103n ph\u00f2ng \u1edf nhi\u1ec1u v\u1ecb tr\u00ed \u0111\u1ecba l\u00fd kh\u00e1c nhau.<\/li>\n\n\n\n<li>VPN b\u1ea3o v\u1ec7 th\u00f4ng tin c\u1ee7a t\u1ed5 ch\u1ee9c kh\u1ecfi m\u1ecdi m\u1ed1i \u0111e d\u1ecda ho\u1eb7c x\u00e2m nh\u1eadp ti\u1ec1m \u1ea9n b\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng c\u00f4ng ngh\u1ec7 \u1ea3o h\u00f3a.<\/li>\n\n\n\n<li>VPN m\u00e3 h\u00f3a l\u01b0u l\u01b0\u1ee3ng truy c\u1eadp internet v\u00e0 ng\u1ee5y trang danh t\u00ednh tr\u1ef1c tuy\u1ebfn.<\/li>\n<\/ul>\n\n\n\n<p>C\u00f3 m\u1ed9t s\u1ed1 lo\u1ea1i VPN sau:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Access VPN:<\/strong> \u0110\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 cung c\u1ea5p k\u1ebft n\u1ed1i cho ng\u01b0\u1eddi d\u00f9ng di \u0111\u1ed9ng t\u1eeb xa v\u00e0 ng\u01b0\u1eddi l\u00e0m vi\u1ec7c t\u1ea1i nh\u00e0. Access VPN \u0111\u00f3ng vai tr\u00f2 l\u00e0 gi\u1ea3i ph\u00e1p thay th\u1ebf cho k\u1ebft n\u1ed1i quay s\u1ed1 ho\u1eb7c k\u1ebft n\u1ed1i ISDN (Integrated Services Digital Network). \u0110\u00e2y l\u00e0 gi\u1ea3i ph\u00e1p chi ph\u00ed th\u1ea5p v\u00e0 cung c\u1ea5p nhi\u1ec1u lo\u1ea1i k\u1ebft n\u1ed1i.<\/li>\n\n\n\n<li><strong>Site-to-Site VPN:<\/strong> Site-to-Site ho\u1eb7c Router-to-Router VPN th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong c\u00e1c c\u00f4ng ty l\u1edbn c\u00f3 chi nh\u00e1nh \u1edf nhi\u1ec1u \u0111\u1ecba \u0111i\u1ec3m kh\u00e1c nhau \u0111\u1ec3 k\u1ebft n\u1ed1i m\u1ea1ng c\u1ee7a m\u1ed9t v\u0103n ph\u00f2ng v\u1edbi m\u1ed9t v\u0103n ph\u00f2ng kh\u00e1c \u1edf nhi\u1ec1u \u0111\u1ecba \u0111i\u1ec3m kh\u00e1c nhau.\u00a0<\/li>\n\n\n\n<li><strong>Intranet VPN: <\/strong>VPN n\u1ed9i b\u1ed9 h\u1eefu \u00edch khi k\u1ebft n\u1ed1i c\u00e1c v\u0103n ph\u00f2ng t\u1eeb xa \u1edf nhi\u1ec1u v\u1ecb tr\u00ed \u0111\u1ecba l\u00fd kh\u00e1c nhau b\u1eb1ng c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng d\u00f9ng chung (k\u1ebft n\u1ed1i internet v\u00e0 m\u00e1y ch\u1ee7) v\u1edbi ch\u00ednh s\u00e1ch truy c\u1eadp gi\u1ed1ng nh\u01b0 m\u1ea1ng WAN (m\u1ea1ng di\u1ec7n r\u1ed9ng) ri\u00eang.<\/li>\n\n\n\n<li><strong>Extranet VPN:<\/strong> Extranet VPN s\u1eed d\u1ee5ng c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng \u0111\u01b0\u1ee3c chia s\u1ebb qua m\u1ea1ng n\u1ed9i b\u1ed9, nh\u00e0 cung c\u1ea5p, kh\u00e1ch h\u00e0ng, \u0111\u1ed1i t\u00e1c v\u00e0 c\u00e1c th\u1ef1c th\u1ec3 kh\u00e1c v\u00e0 k\u1ebft n\u1ed1i h\u1ecd b\u1eb1ng c\u00e1c k\u1ebft n\u1ed1i chuy\u00ean d\u1ee5ng.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-9-s\u1ef1-khac-nhau-gi\u1eefa-hub-switch-va-router-la-gi-nbsp\"><strong>9. S\u1ef1 kh\u00e1c nhau gi\u1eefa hub, switch v\u00e0 router l\u00e0 g\u00ec?<\/strong>&nbsp;<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><\/td><td><strong>Hub<\/strong><\/td><td><strong>Switch<\/strong><\/td><td><strong>Router<\/strong><\/td><\/tr><tr><td>Layer OSI<\/td><td>Physical Layer (Layer 1)<\/td><td>Data Link Layer (Layer 2)<\/td><td>Network Layer (Layer 3)<\/td><\/tr><tr><td>Ch\u1ee9c n\u0103ng<\/td><td>Thi\u1ebft b\u1ecb ch\u00ednh truy\u1ec1n d\u1eef li\u1ec7u \u0111\u1ebfn t\u1ea5t c\u1ea3 c\u00e1c thi\u1ebft b\u1ecb \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i, kh\u00f4ng c\u00f3 t\u00ednh th\u00f4ng minh.<\/td><td>M\u1ed9t thi\u1ebft b\u1ecb ti\u00ean ti\u1ebfn h\u01a1n c\u00f3 ch\u1ee9c n\u0103ng chuy\u1ec3n h\u01b0\u1edbng d\u1eef li\u1ec7u \u0111\u1ebfn c\u00e1c thi\u1ebft b\u1ecb c\u1ee5 th\u1ec3 d\u1ef1a tr\u00ean \u0111\u1ecba ch\u1ec9 MAC.<\/td><td>K\u1ebft n\u1ed1i c\u00e1c m\u1ea1ng kh\u00e1c nhau, \u0111\u1ecbnh tuy\u1ebfn d\u1eef li\u1ec7u gi\u1eefa ch\u00fang v\u00e0 qu\u1ea3n l\u00fd l\u01b0u l\u01b0\u1ee3ng b\u1eb1ng \u0111\u1ecba ch\u1ec9 IP.<\/td><\/tr><tr><td>\u0110\u1ecba ch\u1ec9 s\u1eed d\u1ee5ng<\/td><td>Kh\u00f4ng s\u1eed d\u1ee5ng \u0111\u1ecba ch\u1ec9<\/td><td>\u0110\u1ecba ch\u1ec9 MAC (Layer 2)<\/td><td>\u0110\u1ecba ch\u1ec9 IP (Layer 3)<\/td><\/tr><tr><td>T\u00ednh n\u0103ng n\u00e2ng cao<\/td><td>Kh\u00f4ng c\u00f3<\/td><td>VLAN, STP (Spanning Tree Protocol), Link Aggregation, QoS<\/td><td>ACL, NAT, Firewall, VPN, QoS, DHCP, \u0110\u1ecbnh tuy\u1ebfn \u0111\u1ed9ng<\/td><\/tr><tr><td>Ph\u1ea1m vi ho\u1ea1t \u0111\u1ed9ng<\/td><td>Segment m\u1ea1ng \u0111\u01a1n l\u1ebb<\/td><td>LAN ho\u1eb7c c\u00e1c segment m\u1ea1ng<\/td><td>K\u1ebft n\u1ed1i nhi\u1ec1u m\u1ea1ng kh\u00e1c nhau (LAN-to-LAN, LAN-to-WAN)<\/td><\/tr><tr><td>Ph\u01b0\u01a1ng th\u1ee9c truy\u1ec1n d\u1eef li\u1ec7u<\/td><td>Broadcast (truy\u1ec1n tin qu\u1ea3ng b\u00e1)<\/td><td>Unicast, Multicast, Broadcast<\/td><td>Unicast, Multicast, Broadcast (c\u00f3 ki\u1ec3m so\u00e1t)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-10-gi\u1ea3i-thich-cac-khai-ni\u1ec7m-mac-dhcp-vlan-tcp-va-udp\"><strong>10. Gi\u1ea3i th\u00edch c\u00e1c kh\u00e1i ni\u1ec7m MAC, DHCP, VLAN, TCP v\u00e0 UDP.<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>MAC<\/strong> vi\u1ebft t\u1eaft c\u1ee7a Media Access Control, l\u00e0 m\u00e3 \u0111\u1ecbnh danh duy nh\u1ea5t 48 bit ho\u1eb7c 64 bit c\u1ee7a c\u00e1c thi\u1ebft b\u1ecb trong m\u1ea1ng. MAC c\u0169ng \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 \u0111\u1ecba ch\u1ec9 v\u1eadt l\u00fd \u0111\u01b0\u1ee3c nh\u00fang trong NIC v\u00e0 s\u1eed d\u1ee5ng t\u1ea1i Data Link layer. NIC l\u00e0 th\u00e0nh ph\u1ea7n ph\u1ea7n c\u1ee9ng trong thi\u1ebft b\u1ecb m\u1ea1ng m\u00e0 thi\u1ebft b\u1ecb c\u00f3 th\u1ec3 k\u1ebft n\u1ed1i v\u1edbi m\u1ea1ng.<\/li>\n\n\n\n<li><strong>DHCP<\/strong> vi\u1ebft t\u1eaft t\u1eeb Dynamic Host Configuration Protocol. \u0110\u00e2y l\u00e0 giao th\u1ee9c l\u1edbp \u1ee9ng d\u1ee5ng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 t\u1ef1 \u0111\u1ed9ng c\u1ea5u h\u00ecnh c\u00e1c thi\u1ebft b\u1ecb tr\u00ean m\u1ea1ng IP cho ph\u00e9p ch\u00fang s\u1eed d\u1ee5ng c\u00e1c giao th\u1ee9c d\u1ef1a tr\u00ean TCP v\u00e0 UDP. C\u00e1c m\u00e1y ch\u1ee7 DHCP t\u1ef1 \u0111\u1ed9ng g\u00e1n IP v\u00e0 c\u00e1c c\u1ea5u h\u00ecnh m\u1ea1ng kh\u00e1c cho t\u1eebng thi\u1ebft b\u1ecb ri\u00eang l\u1ebb, cho ph\u00e9p ch\u00fang giao ti\u1ebfp qua m\u1ea1ng IP. DHCP gi\u00fap l\u1ea5y subnet mask, \u0111\u1ecba ch\u1ec9 IP v\u00e0 gi\u00fap ph\u00e2n gi\u1ea3i DNS. Theo m\u1eb7c \u0111\u1ecbnh, n\u00f3 s\u1eed d\u1ee5ng c\u1ed5ng 67.<\/li>\n\n\n\n<li><strong>VLAN<\/strong> (Virtual Local Area Network) ph\u00e2n \u0111o\u1ea1n m\u1ea1ng v\u1eadt l\u00fd th\u00e0nh nhi\u1ec1u m\u1ea1ng logic, c\u1ea3i thi\u1ec7n kh\u1ea3 n\u0103ng qu\u1ea3n l\u00fd l\u01b0u l\u01b0\u1ee3ng v\u00e0 b\u1ea3o m\u1eadt. VLAN ho\u1ea1t \u0111\u1ed9ng t\u1ea1i Layer 2 c\u1ee7a m\u00f4 h\u00ecnh OSI v\u00e0 \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a trong ti\u00eau chu\u1ea9n IEEE 802.1Q. VLAN gi\u00fap gi\u1ea3m mi\u1ec1n qu\u1ea3ng b\u00e1, c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t m\u1ea1ng, t\u0103ng c\u01b0\u1eddng b\u1ea3o m\u1eadt v\u00e0 linh ho\u1ea1t trong qu\u1ea3n l\u00fd m\u1ea1ng. VLAN c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh d\u1ef1a tr\u00ean c\u1ed5ng, \u0111\u1ecba ch\u1ec9 MAC ho\u1eb7c giao th\u1ee9c.<\/li>\n\n\n\n<li><strong>TCP<\/strong> (Transmission Control Protocol) l\u00e0 giao th\u1ee9c h\u01b0\u1edbng k\u1ebft n\u1ed1i \u0111\u1ea3m b\u1ea3o truy\u1ec1n d\u1eef li\u1ec7u \u0111\u00e1ng tin c\u1eady th\u00f4ng qua ki\u1ec3m tra l\u1ed7i v\u00e0 ki\u1ec3m so\u00e1t lu\u1ed3ng. TCP ho\u1ea1t \u0111\u1ed9ng \u1edf Transport Layer (Layer 4). N\u00f3 thi\u1ebft l\u1eadp k\u1ebft n\u1ed1i th\u00f4ng qua qu\u00e1 tr\u00ecnh b\u1eaft tay 3 b\u01b0\u1edbc (SYN, SYN-ACK, ACK), cung c\u1ea5p c\u01a1 ch\u1ebf x\u00e1c nh\u1eadn, s\u1eafp x\u1ebfp l\u1ea1i g\u00f3i tin, ki\u1ec3m so\u00e1t t\u1eafc ngh\u1ebdn v\u00e0 ki\u1ec3m so\u00e1t lu\u1ed3ng. TCP th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng cho c\u00e1c \u1ee9ng d\u1ee5ng y\u00eau c\u1ea7u \u0111\u1ed9 tin c\u1eady cao nh\u01b0 web (HTTP\/HTTPS), email (SMTP, IMAP, POP3), FTP v\u00e0 SSH.<\/li>\n\n\n\n<li><strong>UDP<\/strong> (User Datagram Protocol) l\u00e0 giao th\u1ee9c kh\u00f4ng k\u1ebft n\u1ed1i, g\u1eedi d\u1eef li\u1ec7u m\u00e0 kh\u00f4ng thi\u1ebft l\u1eadp k\u1ebft n\u1ed1i, c\u00f3 \u0111\u1ed9 latency th\u1ea5p h\u01a1n nh\u01b0ng \u0111\u1ed9 tin c\u1eady th\u1ea5p h\u01a1n. UDP c\u0169ng ho\u1ea1t \u0111\u1ed9ng \u1edf Transport Layer nh\u01b0ng kh\u00f4ng cung c\u1ea5p c\u01a1 ch\u1ebf x\u00e1c nh\u1eadn, s\u1eafp x\u1ebfp g\u00f3i tin hay ki\u1ec3m so\u00e1t lu\u1ed3ng. UDP \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng cho c\u00e1c \u1ee9ng d\u1ee5ng y\u00eau c\u1ea7u t\u1ed1c \u0111\u1ed9 v\u00e0 ch\u1ea5p nh\u1eadn m\u1ed9t s\u1ed1 m\u1ea5t m\u00e1t d\u1eef li\u1ec7u nh\u01b0 streaming media, VoIP, tr\u00f2 ch\u01a1i tr\u1ef1c tuy\u1ebfn, DNS v\u00e0 DHCP. Header c\u1ee7a UDP \u0111\u01a1n gi\u1ea3n h\u01a1n TCP, d\u1eabn \u0111\u1ebfn overhead th\u1ea5p h\u01a1n.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-cau-h\u1ecfi-ph\u1ecfng-v\u1ea5n-network-engineer-trung-c\u1ea5p\"><span class=\"ez-toc-section\" id=\"Cau_hoi_phong_van_Network_Engineer_trung_cap\"><\/span><strong>C\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer trung c\u1ea5p<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-11-cong-d\u1ee5ng-c\u1ee7a-b\u1ed9-d\u1ecbnh-tuy\u1ebfn-la-gi-va-no-khac-v\u1edbi-c\u1ed5ng-k\u1ebft-n\u1ed1i-nh\u01b0-th\u1ebf-nao-nbsp\"><strong>11. C\u00f4ng d\u1ee5ng c\u1ee7a b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn l\u00e0 g\u00ec v\u00e0 n\u00f3 kh\u00e1c v\u1edbi c\u1ed5ng k\u1ebft n\u1ed1i nh\u01b0 th\u1ebf n\u00e0o?<\/strong>&nbsp;<\/h3>\n\n\n\n<p>Router (b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn) l\u00e0 m\u1ed9t thi\u1ebft b\u1ecb m\u1ea1ng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 k\u1ebft n\u1ed1i hai ho\u1eb7c nhi\u1ec1u ph\u00e2n \u0111o\u1ea1n m\u1ea1ng. Router \u0111\u1ecbnh h\u01b0\u1edbng l\u01b0u l\u01b0\u1ee3ng trong m\u1ea1ng, truy\u1ec1n th\u00f4ng tin v\u00e0 d\u1eef li\u1ec7u nh\u01b0 trang web, email, h\u00ecnh \u1ea3nh, video, v.v. t\u1eeb ngu\u1ed3n \u0111\u1ebfn \u0111\u00edch d\u01b0\u1edbi d\u1ea1ng c\u00e1c packet.&nbsp;<\/p>\n\n\n\n<p>C\u00e1c c\u1ed5ng k\u1ebft n\u1ed1i c\u0169ng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 \u0111\u1ecbnh tuy\u1ebfn v\u00e0 \u0111i\u1ec1u ch\u1ec9nh l\u01b0u l\u01b0\u1ee3ng m\u1ea1ng, nh\u01b0ng ch\u00fang c\u0169ng c\u00f3 th\u1ec3 g\u1eedi d\u1eef li\u1ec7u gi\u1eefa hai m\u1ea1ng kh\u00f4ng gi\u1ed1ng nhau. Trong khi \u0111\u00f3 router ho\u1ea1t \u0111\u1ed9ng \u1edf network layer v\u00e0 ch\u1ec9 c\u00f3 th\u1ec3 g\u1eedi d\u1eef li\u1ec7u \u0111\u1ebfn c\u00e1c m\u1ea1ng t\u01b0\u01a1ng t\u1ef1.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-12-xac-d\u1ecbnh-4-layer-khac-nhau-c\u1ee7a-mo-hinh-tham-chi\u1ebfu-tcp-ip-nbsp\"><strong>12. X\u00e1c \u0111\u1ecbnh 4 layer kh\u00e1c nhau c\u1ee7a m\u00f4 h\u00ecnh tham chi\u1ebfu TCP\/IP<\/strong>&nbsp;<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>Layer<\/strong><\/td><td><strong>Mi\u00eau t\u1ea3<\/strong><\/td><\/tr><tr><td>Network Access\/Network Interface<\/td><td>T\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi Layer 1 v\u00e0 2 c\u1ee7a m\u00f4 h\u00ecnh OSI. Ch\u1ecbu tr\u00e1ch nhi\u1ec7m truy\u1ec1n d\u1eef li\u1ec7u gi\u1eefa c\u00e1c thi\u1ebft b\u1ecb trong c\u00f9ng m\u1ed9t m\u1ea1ng. C\u00e1c giao th\u1ee9c ch\u00ednh: Ethernet, PPP, Token Ring, ARP, RARP, Frame Relay.<\/td><\/tr><tr><td>Internet<\/td><td>T\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi Network Layer (Layer 3) c\u1ee7a m\u00f4 h\u00ecnh OSI. X\u1eed l\u00fd \u0111\u1ecba ch\u1ec9 IP v\u00e0 \u0111\u1ecbnh tuy\u1ebfn g\u00f3i tin gi\u1eefa c\u00e1c m\u1ea1ng. C\u00e1c giao th\u1ee9c ch\u00ednh: IP, ICMP, IGMP.<\/td><\/tr><tr><td>Transport<\/td><td>Ch\u1ee9c n\u0103ng c\u1ee7a Transport layer g\u1ea7n gi\u1ed1ng nh\u01b0 OSI Transport layer, cho ph\u00e9p c\u00e1c th\u1ef1c th\u1ec3 ngang h\u00e0ng tr\u00ean m\u1ea1ng th\u1ef1c hi\u1ec7n cu\u1ed9c tr\u00f2 chuy\u1ec7n.<\/td><\/tr><tr><td>Application<\/td><td>T\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi Layer 5, 6, 7 c\u1ee7a m\u00f4 h\u00ecnh OSI. Cung c\u1ea5p giao di\u1ec7n cho \u1ee9ng d\u1ee5ng ng\u01b0\u1eddi d\u00f9ng v\u00e0 c\u00e1c d\u1ecbch v\u1ee5 m\u1ea1ng. C\u00e1c giao th\u1ee9c ch\u00ednh: HTTP, FTP, SMTP, DNS, Telnet, SSH, SNMP.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-13-kinh-nghi\u1ec7m-c\u1ee7a-b\u1ea1n-v\u1edbi-cac-giao-th\u1ee9c-b\u1ea3o-m\u1eadt-m\u1ea1ng-la-gi-va-lam-th\u1ebf-nao-d\u1ec3-d\u1ea3m-b\u1ea3o-moi-tr\u01b0\u1eddng-m\u1ea1ng-an-toan\"><strong>13. Kinh nghi\u1ec7m c\u1ee7a b\u1ea1n v\u1edbi c\u00e1c giao th\u1ee9c b\u1ea3o m\u1eadt m\u1ea1ng l\u00e0 g\u00ec v\u00e0 l\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o m\u00f4i tr\u01b0\u1eddng m\u1ea1ng an to\u00e0n?<\/strong><\/h3>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>L\u01b0u \u00fd: Sau \u0111\u00e2y l\u00e0 v\u00ed d\u1ee5 v\u1ec1 m\u1eabu c\u00e2u tr\u1ea3 l\u1eddi m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o, h\u00e3y tr\u1ea3 l\u1eddi theo kinh nghi\u1ec7m c\u00e1 nh\u00e2n.<\/p>\n<\/blockquote>\n\n\n\n<p>T\u00f4i c\u00f3 nhi\u1ec1u kinh nghi\u1ec7m v\u1edbi c\u00e1c giao th\u1ee9c b\u1ea3o m\u1eadt nh\u01b0 IPSec v\u00e0 SSL cho c\u1ea5u h\u00ecnh VPN. T\u00f4i \u0111\u00e3 l\u00e3nh \u0111\u1ea1o m\u1ed9t d\u1ef1 \u00e1n tri\u1ec3n khai firewall v\u00e0 h\u1ec7 th\u1ed1ng ph\u00e1t hi\u1ec7n x\u00e2m nh\u1eadp, gi\u00fap gi\u1ea3m 40% c\u00e1c l\u1ed7 h\u1ed5ng ti\u1ec1m \u1ea9n. T\u00f4i th\u01b0\u1eddng xuy\u00ean ti\u1ebfn h\u00e0nh \u0111\u00e1nh gi\u00e1 b\u1ea3o m\u1eadt v\u00e0 c\u1eadp nh\u1eadt c\u00e1c xu h\u01b0\u1edbng m\u1edbi nh\u1ea5t v\u1ec1 an ninh m\u1ea1ng \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o m\u1ea1ng c\u1ee7a ch\u00fang t\u00f4i lu\u00f4n an to\u00e0n.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-14-phan-bi\u1ec7t-osi-va-tcp-ip-nbsp\"><strong>14. Ph\u00e2n bi\u1ec7t OSI v\u00e0 TCP\/IP<\/strong>&nbsp;<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>M\u00f4 h\u00ecnh tham chi\u1ebfu OSI<\/strong><\/td><td><strong>M\u00f4 h\u00ecnh tham chi\u1ebfu TCP\/IP<\/strong><\/td><\/tr><tr><td>Ki\u1ebfn tr\u00fac 7 layer<\/td><td>Ki\u1ebfn tr\u00fac 4 layer<\/td><\/tr><tr><td>C\u00e1c ranh gi\u1edbi v\u00e0 ch\u1ee9c n\u0103ng c\u1ed1 \u0111\u1ecbnh cho t\u1eebng layer<\/td><td>Ki\u1ebfn tr\u00fac linh ho\u1ea1t kh\u00f4ng c\u00f3 ranh gi\u1edbi nghi\u00eam ng\u1eb7t gi\u1eefa c\u00e1c layer<\/td><\/tr><tr><td>\u0110\u1ed9 tin c\u1eady th\u1ea5p<\/td><td>\u0110\u1ed9 tin c\u1eady cao<\/td><\/tr><tr><td>Ph\u01b0\u01a1ng ph\u00e1p ti\u1ebfp c\u1eadn Vertical Layer<\/td><td>Ph\u01b0\u01a1ng ph\u00e1p ti\u1ebfp c\u1eadn Horizontal Layer<\/td><\/tr><tr><td>Ph\u00e1t tri\u1ec3n b\u1edfi ISO (International Organization for Standardization)<\/td><td>Ph\u00e1t tri\u1ec3n b\u1edfi DARPA (Defense Advanced Research Projects Agency)<\/td><\/tr><tr><td>M\u00f4 h\u00ecnh l\u00fd thuy\u1ebft \u0111\u01b0\u1ee3c ph\u00e1t tri\u1ec3n tr\u01b0\u1edbc khi c\u00f3 c\u00e1c giao th\u1ee9c<\/td><td>M\u00f4 h\u00ecnh th\u1ef1c t\u1ebf ph\u00e1t tri\u1ec3n sau khi c\u00e1c giao th\u1ee9c \u0111\u00e3 t\u1ed3n t\u1ea1i<\/td><\/tr><tr><td>T\u00e1ch bi\u1ec7t c\u00e1c ch\u1ee9c n\u0103ng Presentation v\u00e0 Session<\/td><td>G\u1ed9p Presentation v\u00e0 Session v\u00e0o Application layer<\/td><\/tr><tr><td>\u00cdt \u0111\u01b0\u1ee3c tri\u1ec3n khai trong th\u1ef1c t\u1ebf<\/td><td>\u0110\u01b0\u1ee3c tri\u1ec3n khai r\u1ed9ng r\u00e3i tr\u00ean Internet v\u00e0 m\u1ea1ng hi\u1ec7n \u0111\u1ea1i<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-15-gi\u1ea3i-thich-khai-ni\u1ec7m-cac-protocol-ftp-udp-tcp-nbsp\"><strong>15. Gi\u1ea3i th\u00edch kh\u00e1i ni\u1ec7m c\u00e1c protocol FTP, UDP, TCP<\/strong>&nbsp;<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>FTP:<\/strong> FTP s\u1eed d\u1ee5ng c\u1ed5ng 21 cho k\u00eanh \u0111i\u1ec1u khi\u1ec3n v\u00e0 c\u1ed5ng 20 cho k\u00eanh d\u1eef li\u1ec7u khi \u1edf ch\u1ebf \u0111\u1ed9 ch\u1ee7 \u0111\u1ed9ng. FTP c\u00f3 hai ch\u1ebf \u0111\u1ed9 ho\u1ea1t \u0111\u1ed9ng ch\u00ednh: Active Mode v\u00e0 Passive Mode. FTP c\u00f3 c\u00e1c bi\u1ebfn th\u1ec3 b\u1ea3o m\u1eadt h\u01a1n nh\u01b0 FTPS (FTP Secure) s\u1eed d\u1ee5ng SSL\/TLS v\u00e0 SFTP (SSH File Transfer Protocol) ho\u1ea1t \u0111\u1ed9ng qua SSH.<\/li>\n\n\n\n<li><strong>UDP:<\/strong> UDP vi\u1ebft t\u1eaft t\u1eeb User Datagram Protocol, d\u1ef1a tr\u00ean Datagram. UDP ch\u1ee7 y\u1ebfu \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 ph\u00e1t \u0111a h\u01b0\u1edbng v\u00e0 ph\u00e1t s\u00f3ng. Ch\u1ee9c n\u0103ng c\u1ee7a UDP g\u1ea7n gi\u1ed1ng v\u1edbi TCP\/IP ngo\u1ea1i tr\u1eeb three-way handshake v\u00e0 ki\u1ec3m tra l\u1ed7i. UDP s\u1eed d\u1ee5ng m\u1ed9t ph\u01b0\u01a1ng th\u1ee9c truy\u1ec1n \u0111\u01a1n gi\u1ea3n m\u00e0 kh\u00f4ng c\u00f3 b\u1ea5t k\u1ef3 handshake n\u00e0o khi\u1ebfn n\u00f3 k\u00e9m tin c\u1eady h\u01a1n.<\/li>\n\n\n\n<li><strong>TCP:<\/strong> TCP ho\u1eb7c TCP\/IP l\u00e0 Transmission Control Protocol\/Internet Protocol &#8211; m\u1ed9t t\u1eadp h\u1ee3p c\u00e1c quy t\u1eafc quy\u1ebft \u0111\u1ecbnh c\u00e1ch m\u00e1y t\u00ednh k\u1ebft n\u1ed1i v\u1edbi Internet v\u00e0 c\u00e1ch truy\u1ec1n d\u1eef li\u1ec7u qua m\u1ea1ng. TCP t\u1ea1o ra m\u1ed9t m\u1ea1ng \u1ea3o khi c\u00f3 nhi\u1ec1u h\u01a1n m\u1ed9t m\u00e1y t\u00ednh \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i m\u1ea1ng v\u00e0 s\u1eed d\u1ee5ng m\u00f4 h\u00ecnh three-way handshake \u0111\u1ec3 thi\u1ebft l\u1eadp k\u1ebft n\u1ed1i khi\u1ebfn TCP \u0111\u00e1ng tin c\u1eady h\u01a1n.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-16-mo-t\u1ea3-backbone-network\"><strong>16. M\u00f4 t\u1ea3 backbone network<\/strong><\/h3>\n\n\n\n<p>Backbone network hay c\u00f2n g\u1ecdi core network, l\u00e0 n\u1ec1n t\u1ea3ng c\u1ee7a b\u1ea5t k\u1ef3 h\u1ec7 th\u1ed1ng m\u1ea1ng n\u00e0o v\u00e0 k\u1ebft n\u1ed1i t\u1ea5t c\u1ea3 c\u00e1c th\u00e0nh ph\u1ea7n tr\u00ean m\u1ea1ng. Kh\u1ea3 n\u0103ng k\u1ebft n\u1ed1i v\u00e0 c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng dung l\u01b0\u1ee3ng cao c\u1ee7a n\u00f3 c\u00f3 th\u1ec3 h\u1ed7 tr\u1ee3 nhi\u1ec1u thi\u1ebft b\u1ecb v\u00e0 m\u00e1y ch\u1ee7 v\u00ec b\u0103ng th\u00f4ng \u0111\u01b0\u1ee3c t\u0103ng c\u01b0\u1eddng, khi\u1ebfn n\u00f3 tr\u1edf th\u00e0nh tuy\u1ebfn \u0111\u01b0\u1eddng nhanh nh\u1ea5t \u0111\u1ec3 d\u1eef li\u1ec7u di chuy\u1ec3n qua m\u1ea1ng.&nbsp;<\/p>\n\n\n\n<p>Backbone network c\u00f3 th\u1ec3 li\u00ean k\u1ebft nhi\u1ec1u m\u1ea1ng kh\u00e1c nhau trong m\u1ed9t t\u00f2a nh\u00e0, ch\u1eb3ng h\u1ea1n nh\u01b0 m\u1ed9t doanh nghi\u1ec7p ho\u1eb7c qua nhi\u1ec1u t\u00f2a nh\u00e0 nh\u01b0 khu\u00f4n vi\u00ean tr\u01b0\u1eddng \u0111\u1ea1i h\u1ecdc. M\u1ed9t s\u1ed1 backbone network c\u00f3 th\u1ec3 k\u1ebft n\u1ed1i c\u00e1c thi\u1ebft b\u1ecb v\u00e0 m\u00e1y ch\u1ee7 tr\u00ean m\u1ed9t khu v\u1ef1c r\u1ed9ng l\u1edbn, ch\u1eb3ng h\u1ea1n nh\u01b0 m\u1ea1ng \u0111\u01b0\u1ee3c c\u00e1c c\u00f4ng ty vi\u1ec5n th\u00f4ng s\u1eed d\u1ee5ng, \u0111\u00f3 l\u00e0 l\u00fd do t\u1ea1i sao ch\u00fang ta th\u01b0\u1eddng g\u1ecdi n\u00f3 l\u00e0 meta-network.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-17-nguyen-nhan-ph\u1ed5-bi\u1ebfn-gay-ra-tinh-tr\u1ea1ng-t\u1eafc-ngh\u1ebdn-m\u1ea1ng-la-gi-va-cach-gi\u1ea3i-quy\u1ebft-cho-t\u1eebng-nguyen-nhan\"><strong>17. Nguy\u00ean nh\u00e2n ph\u1ed5 bi\u1ebfn g\u00e2y ra t\u00ecnh tr\u1ea1ng t\u1eafc ngh\u1ebdn m\u1ea1ng l\u00e0 g\u00ec? V\u00e0 c\u00e1ch gi\u1ea3i quy\u1ebft cho t\u1eebng nguy\u00ean nh\u00e2n<\/strong><\/h3>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><em>L\u01b0u \u00fd: Sau \u0111\u00e2y l\u00e0 v\u00ed d\u1ee5 v\u1ec1 m\u1eabu c\u00e2u tr\u1ea3 l\u1eddi m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o, h\u00e3y tr\u1ea3 l\u1eddi theo kinh nghi\u1ec7m c\u00e1 nh\u00e2n<\/em>.<\/p>\n<\/blockquote>\n\n\n\n<p>T\u1eafc ngh\u1ebdn m\u1ea1ng x\u1ea3y ra khi nhu c\u1ea7u v\u1ec1 b\u0103ng th\u00f4ng v\u01b0\u1ee3t qu\u00e1 dung l\u01b0\u1ee3ng kh\u1ea3 d\u1ee5ng. M\u1ed9t s\u1ed1 y\u1ebfu t\u1ed1 c\u00f3 th\u1ec3 g\u00f3p ph\u1ea7n g\u00e2y ra t\u00ecnh tr\u1ea1ng n\u00e0y v\u00e0 c\u00e1ch t\u00f4i gi\u1ea3i quy\u1ebft nh\u01b0 sau:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>L\u01b0u l\u01b0\u1ee3ng truy c\u1eadp qu\u00e1 m\u1ee9c t\u1eeb ng\u01b0\u1eddi d\u00f9ng ho\u1eb7c \u1ee9ng d\u1ee5ng c\u00f3 th\u1ec3 l\u00e0m qu\u00e1 t\u1ea3i c\u00e1c li\u00ean k\u1ebft m\u1ea1ng. L\u00fac n\u00e0y, t\u00f4i s\u1ebd tri\u1ec3n khai c\u00e1c gi\u1ea3i ph\u00e1p c\u00e2n b\u1eb1ng t\u1ea3i (load balancing) v\u00e0 m\u1edf r\u1ed9ng dung l\u01b0\u1ee3ng \u0111\u01b0\u1eddng truy\u1ec1n (bandwidth scaling) t\u1ea1i c\u00e1c \u0111i\u1ec3m ngh\u1ebdn ti\u1ec1m \u1ea9n.<\/li>\n\n\n\n<li>B\u0103ng th\u00f4ng kh\u00f4ng \u0111\u1ee7 tr\u00ean c\u00e1c li\u00ean k\u1ebft quan tr\u1ecdng s\u1ebd t\u1ea1o ra t\u00ecnh tr\u1ea1ng t\u1eafc ngh\u1ebdn. C\u00e1ch gi\u1ea3i quy\u1ebft th\u01b0\u1eddng l\u00e0 n\u00e2ng c\u1ea5p b\u0103ng th\u00f4ng c\u00e1c li\u00ean k\u1ebft m\u1ea1ng quan tr\u1ecdng v\u00e0 \u01b0u ti\u00ean l\u01b0u l\u01b0\u1ee3ng cho c\u00e1c \u1ee9ng d\u1ee5ng quan tr\u1ecdng.<\/li>\n\n\n\n<li>C\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng b\u1ecb l\u1ed7i, nh\u01b0 b\u1ed9 chuy\u1ec3n m\u1ea1ch ho\u1eb7c b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn b\u1ecb tr\u1ee5c tr\u1eb7c, c\u00f3 th\u1ec3 l\u00e0m gi\u1ea3m hi\u1ec7u su\u1ea5t. \u0110\u00f3 l\u00e0 l\u00fd do c\u1ea7n th\u1ef1c hi\u1ec7n gi\u00e1m s\u00e1t ch\u1ee7 \u0111\u1ed9ng v\u00e0 c\u00f3 k\u1ebf ho\u1ea1ch d\u1ef1 ph\u00f2ng cho c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng c\u1ed1t l\u00f5i.<\/li>\n\n\n\n<li>Ch\u1ea5t l\u01b0\u1ee3ng d\u1ecbch v\u1ee5 (QoS) \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh kh\u00f4ng \u0111\u00fang c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn ph\u00e2n b\u1ed5 b\u0103ng th\u00f4ng kh\u00f4ng c\u00e2n b\u1eb1ng. Do \u0111\u00f3, t\u00f4i s\u1ebd r\u00e0 so\u00e1t v\u00e0 c\u1ea5u h\u00ecnh l\u1ea1i ch\u00ednh s\u00e1ch QoS \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o ph\u00e2n b\u1ed5 b\u0103ng th\u00f4ng h\u1ee3p l\u00fd d\u1ef1a tr\u00ean y\u00eau c\u1ea7u d\u1ecbch v\u1ee5 v\u00e0 m\u1ee9c \u0111\u1ed9 \u01b0u ti\u00ean.<\/li>\n\n\n\n<li>B\u00e3o ph\u00e1t s\u00f3ng khi l\u01b0u l\u01b0\u1ee3ng ph\u00e1t s\u00f3ng qu\u00e1 m\u1ee9c l\u00e0m ng\u1eadp m\u1ea1ng, c\u00f3 th\u1ec3 l\u00e0m gi\u1ea3m hi\u1ec7u su\u1ea5t. C\u00e1ch gi\u1ea3i quy\u1ebft c\u1ee7a t\u00f4i l\u00e0 ph\u00e2n chia m\u1ea1ng th\u00e0nh c\u00e1c VLAN \u0111\u1ec3 gi\u1edbi h\u1ea1n ph\u1ea1m vi c\u1ee7a l\u01b0u l\u01b0\u1ee3ng qu\u1ea3ng b\u00e1 v\u00e0 c\u1ea5u h\u00ecnh c\u00e1c giao th\u1ee9c ch\u1ed1ng l\u1eb7p (v\u00ed d\u1ee5: Spanning Tree Protocol).<\/li>\n\n\n\n<li>T\u00ecnh tr\u1ea1ng t\u1eafc ngh\u1ebdn \u1ee9ng d\u1ee5ng, khi m\u00e1y ch\u1ee7 ho\u1eb7c \u1ee9ng d\u1ee5ng kh\u00f4ng th\u1ec3 theo k\u1ecbp c\u00e1c y\u00eau c\u1ea7u, c\u0169ng c\u00f3 th\u1ec3 bi\u1ec3u hi\u1ec7n d\u01b0\u1edbi d\u1ea1ng t\u1eafc ngh\u1ebdn m\u1ea1ng. \u0110\u1ec3 gi\u1ea3i quy\u1ebft, t\u00f4i t\u1ed1i \u01b0u h\u00f3a hi\u1ec7u su\u1ea5t \u1ee9ng d\u1ee5ng v\u00e0 m\u00e1y ch\u1ee7, \u0111\u1ed3ng th\u1eddi tri\u1ec3n khai c\u00e1c k\u1ef9 thu\u1eadt nh\u01b0 caching ho\u1eb7c t\u0103ng c\u01b0\u1eddng t\u00e0i nguy\u00ean ph\u1ea7n c\u1ee9ng.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-18-ch\u1ec9-ra-s\u1ef1-khac-bi\u1ec7t-gi\u1eefa-switch-layer-2-layer-3\"><strong>18. Ch\u1ec9 ra s\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa Switch Layer 2, Layer 3<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Switch Layer 2<\/strong>: Ho\u1ea1t \u0111\u1ed9ng \u1edf Data Link layer, chuy\u1ec3n ti\u1ebfp khung d\u1eef li\u1ec7u d\u1ef1a tr\u00ean \u0111\u1ecba ch\u1ec9 MAC.\u00a0<\/li>\n\n\n\n<li><strong>Switch Layer 3<\/strong>: Ho\u1ea1t \u0111\u1ed9ng \u1edf Network layer, c\u00f3 kh\u1ea3 n\u0103ng \u0111\u1ecbnh tuy\u1ebfn c\u00e1c g\u00f3i tin d\u1ef1a tr\u00ean \u0111\u1ecba ch\u1ec9 IP.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-19-l2vpn-va-l3vpn-ho\u1ea1t-d\u1ed9ng-nh\u01b0-th\u1ebf-nao-qua-mpls-nbsp\"><strong>19. L2VPN v\u00e0 L3VPN ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o qua MPLS?<\/strong>&nbsp;<\/h3>\n\n\n\n<p>L2VPN m\u1edf r\u1ed9ng m\u1ea1ng Layer 2 qua MPLS, cho ph\u00e9p c\u00e1c thi\u1ebft b\u1ecb \u1edf c\u00e1c v\u1ecb tr\u00ed kh\u00e1c nhau giao ti\u1ebfp nh\u01b0 th\u1ec3 ch\u00fang \u0111ang \u1edf tr\u00ean c\u00f9ng m\u1ed9t m\u1ea1ng c\u1ee5c b\u1ed9. Trong khi \u0111\u00f3, L3VPN cung c\u1ea5p k\u1ebft n\u1ed1i Layer 3 qua MPLS, t\u1ea1o ra c\u00e1c m\u1ea1ng \u0111\u1ecbnh tuy\u1ebfn ri\u00eang \u1ea3o gi\u00fap ph\u00e2n t\u00e1ch l\u01b0u l\u01b0\u1ee3ng gi\u1eefa c\u00e1c kh\u00e1ch h\u00e0ng kh\u00e1c nhau.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-20-lam-th\u1ebf-nao-d\u1ec3-tri\u1ec3n-khai-va-qu\u1ea3n-ly-sdn-trong-m\u1ea1ng-doanh-nghi\u1ec7p\"><strong>20. L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 tri\u1ec3n khai v\u00e0 qu\u1ea3n l\u00fd SDN trong m\u1ea1ng doanh nghi\u1ec7p?<\/strong><\/h3>\n\n\n\n<p>T\u00f4i tri\u1ec3n khai SDN b\u1eb1ng c\u00e1ch tri\u1ec3n khai b\u1ed9 \u0111i\u1ec1u khi\u1ec3n SDN v\u00e0 b\u1ed9 chuy\u1ec3n m\u1ea1ch t\u01b0\u01a1ng th\u00edch. Qu\u1ea3n l\u00fd SDN th\u00f4ng qua API do b\u1ed9 \u0111i\u1ec1u khi\u1ec3n SDN cung c\u1ea5p, c\u1ea5u h\u00ecnh ch\u00ednh s\u00e1ch m\u1ea1ng v\u00e0 s\u1eed d\u1ee5ng \u1ea3o h\u00f3a m\u1ea1ng \u0111\u1ec3 t\u1ed1i \u01b0u h\u00f3a lu\u1ed3ng l\u01b0u l\u01b0\u1ee3ng v\u00e0 t\u00e0i nguy\u00ean.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-cau-h\u1ecfi-ph\u1ecfng-v\u1ea5n-network-engineer-c\u1ea5p-cao\"><span class=\"ez-toc-section\" id=\"Cau_hoi_phong_van_Network_Engineer_cap_cao\"><\/span><strong>C\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer c\u1ea5p cao<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-21-lam-th\u1ebf-nao-d\u1ec3-d\u1ea3m-b\u1ea3o-an-ninh-m\u1ea1ng-trong-khi-v\u1eabn-duy-tri-hi\u1ec7u-su\u1ea5t\"><span class=\"ez-toc-section\" id=\"21_Lam_the_nao_de_dam_bao_an_ninh_mang_trong_khi_van_duy_tri_hieu_suat\"><\/span><strong>21. L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o an ninh m\u1ea1ng trong khi v\u1eabn duy tr\u00ec hi\u1ec7u su\u1ea5t?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>L\u01b0u \u00fd: Sau \u0111\u00e2y l\u00e0 v\u00ed d\u1ee5 v\u1ec1 m\u1eabu c\u00e2u tr\u1ea3 l\u1eddi m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o, h\u00e3y tr\u1ea3 l\u1eddi theo kinh nghi\u1ec7m c\u00e1 nh\u00e2n.<\/p>\n<\/blockquote>\n\n\n\n<p>T\u00f4i \u0111\u00e3 tri\u1ec3n khai ph\u01b0\u01a1ng ph\u00e1p b\u1ea3o m\u1eadt nhi\u1ec1u l\u1edbp b\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng firewall, h\u1ec7 th\u1ed1ng ph\u00e1t hi\u1ec7n x\u00e2m nh\u1eadp v\u00e0 \u0111\u00e1nh gi\u00e1 l\u1ed7 h\u1ed5ng th\u01b0\u1eddng xuy\u00ean. T\u00f4i \u0111\u1ea3m b\u1ea3o r\u1eb1ng c\u00e1c bi\u1ec7n ph\u00e1p b\u1ea3o m\u1eadt kh\u00f4ng l\u00e0m gi\u1ea3m hi\u1ec7u su\u1ea5t b\u1eb1ng c\u00e1ch t\u1ed1i \u01b0u h\u00f3a c\u00e1c quy t\u1eafc firewall v\u00e0 ti\u1ebfn h\u00e0nh c\u00e1c b\u00e0i ki\u1ec3m tra hi\u1ec7u su\u1ea5t m\u1ea1ng th\u01b0\u1eddng xuy\u00ean.<\/p>\n\n\n\n<p>Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y kh\u00f4ng ch\u1ec9 b\u1ea3o m\u1eadt m\u1ea1ng c\u1ee7a ch\u00fang t\u00f4i m\u00e0 c\u00f2n duy tr\u00ec th\u1eddi gian ho\u1ea1t \u0111\u1ed9ng 99,9%, \u0111i\u1ec1u n\u00e0y r\u1ea5t quan tr\u1ecdng \u0111\u1ed1i v\u1edbi kh\u00e1ch h\u00e0ng trong l\u0129nh v\u1ef1c t\u00e0i ch\u00ednh.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-22-so-sanh-gi\u1eefa-tcp-va-udp\"><strong>22. So s\u00e1nh gi\u1eefa TCP v\u00e0 UDP<\/strong><\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>TCP<\/strong><\/td><td><strong>UDP<\/strong><\/td><\/tr><tr><td>Giao th\u1ee9c h\u01b0\u1edbng k\u1ebft n\u1ed1i<\/td><td>Giao th\u1ee9c kh\u00f4ng k\u1ebft n\u1ed1i<\/td><\/tr><tr><td>\u0110\u00e1ng tin c\u1eady<\/td><td>\u00cdt tin c\u1eady h\u01a1n<\/td><\/tr><tr><td>Truy\u1ec1n ch\u1eadm h\u01a1n<\/td><td>Truy\u1ec1n t\u1ea3i nhanh h\u01a1n<\/td><\/tr><tr><td>Th\u1ee9 t\u1ef1 c\u00e1c packet c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c b\u1ea3o to\u00e0n ho\u1eb7c c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eafp x\u1ebfp l\u1ea1i<\/td><td>Th\u1ee9 t\u1ef1 c\u00e1c packet kh\u00f4ng c\u1ed1 \u0111\u1ecbnh v\u00e0 c\u00e1c packet \u0111\u1ed9c l\u1eadp v\u1edbi nhau<\/td><\/tr><tr><td>S\u1eed d\u1ee5ng m\u00f4 h\u00ecnh three-way handshake \u0111\u1ec3 k\u1ebft n\u1ed1i<\/td><td>K\u1ebft n\u1ed1i kh\u00f4ng handshake<\/td><\/tr><tr><td>C\u00e1c packet TCP c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng n\u1eb7ng<\/td><td>C\u00e1c packet UDP c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng nh\u1eb9<\/td><\/tr><tr><td>Cung c\u1ea5p c\u01a1 ch\u1ebf ki\u1ec3m tra l\u1ed7i<\/td><td>Kh\u00f4ng c\u00f3 ki\u1ec3m tra l\u1ed7i<\/td><\/tr><tr><td>C\u00e1c giao th\u1ee9c nh\u01b0 HTTP, FTP, Telnet, SMTP, HTTPS, v.v. s\u1eed d\u1ee5ng TCP \u1edf Transport layer<\/td><td>C\u00e1c giao th\u1ee9c nh\u01b0 DNS, RIP, SNMP, RTP, BOOTP, TFTP, NIP, v.v. s\u1eed d\u1ee5ng UDP \u1edf Transport layer<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-23-khi-b\u1ea1n-nh\u1eadp-google-com-vao-trinh-duy\u1ec7t-va-nh\u1ea5n-enter-di\u1ec1u-gi-s\u1ebd-x\u1ea3y-ra-t\u1eeb-goc-d\u1ed9-m\u1ea1ng-va-h\u1ec7-th\u1ed1ng-hay-mo-t\u1ea3-toan-b\u1ed9-qua-trinh\"><strong>23. Khi b\u1ea1n nh\u1eadp &#8220;google.com&#8221; v\u00e0o tr\u00ecnh duy\u1ec7t v\u00e0 nh\u1ea5n Enter, \u0111i\u1ec1u g\u00ec s\u1ebd x\u1ea3y ra t\u1eeb g\u00f3c \u0111\u1ed9 m\u1ea1ng v\u00e0 h\u1ec7 th\u1ed1ng? H\u00e3y m\u00f4 t\u1ea3 to\u00e0n b\u1ed9 qu\u00e1 tr\u00ecnh.<\/strong><\/h3>\n\n\n\n<p>Khi ng\u01b0\u1eddi d\u00f9ng nh\u1eadp &#8220;google.com&#8221; v\u00e0o tr\u00ecnh duy\u1ec7t v\u00e0 nh\u1ea5n Enter, qu\u00e1 tr\u00ecnh di\u1ec5n ra qua nhi\u1ec1u b\u01b0\u1edbc nh\u01b0 sau:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u0110\u1ea7u ti\u00ean, tr\u00ecnh duy\u1ec7t ki\u1ec3m tra xem n\u1ed9i dung c\u00f3 m\u1edbi v\u00e0 hi\u1ec3n th\u1ecb trong b\u1ed9 nh\u1edb \u0111\u1ec7m (cache) kh\u00f4ng.\u00a0<\/li>\n\n\n\n<li>N\u1ebfu kh\u00f4ng, tr\u00ecnh duy\u1ec7t s\u1ebd ki\u1ec3m tra xem IP c\u1ee7a URL c\u00f3 trong b\u1ed9 nh\u1edb \u0111\u1ec7m (browser v\u00e0 OS) hay kh\u00f4ng, n\u1ebfu kh\u00f4ng, h\u00e3y y\u00eau c\u1ea7u h\u1ec7 \u0111i\u1ec1u h\u00e0nh th\u1ef1c hi\u1ec7n tra c\u1ee9u DNS b\u1eb1ng UDP \u0111\u1ec3 l\u1ea5y \u0111\u1ecba ch\u1ec9 IP t\u01b0\u01a1ng \u1ee9ng c\u1ee7a URL t\u1eeb m\u00e1y ch\u1ee7 DNS \u0111\u1ec3 thi\u1ebft l\u1eadp k\u1ebft n\u1ed1i TCP m\u1edbi.\u00a0<\/li>\n\n\n\n<li>Sau khi c\u00f3 \u0111\u1ecba ch\u1ec9 IP, tr\u00ecnh duy\u1ec7t thi\u1ebft l\u1eadp k\u1ebft n\u1ed1i TCP v\u1edbi server th\u00f4ng qua quy tr\u00ecnh b\u1eaft tay 3 b\u01b0\u1edbc (three-way handshake).<\/li>\n\n\n\n<li>Y\u00eau c\u1ea7u HTTP \u0111\u01b0\u1ee3c g\u1eedi \u0111\u1ebfn m\u00e1y ch\u1ee7 b\u1eb1ng k\u1ebft n\u1ed1i TCP.\u00a0<\/li>\n\n\n\n<li>C\u00e1c m\u00e1y ch\u1ee7 web ch\u1ea1y tr\u00ean server x\u1eed l\u00fd y\u00eau c\u1ea7u HTTP \u0111\u1ebfn v\u00e0 g\u1eedi ph\u1ea3n h\u1ed3i HTTP.\u00a0<\/li>\n\n\n\n<li>Tr\u00ecnh duy\u1ec7t x\u1eed l\u00fd ph\u1ea3n h\u1ed3i HTTP \u0111\u01b0\u1ee3c g\u1eedi b\u1edfi m\u00e1y ch\u1ee7 v\u00e0 c\u00f3 th\u1ec3 \u0111\u00f3ng k\u1ebft n\u1ed1i TCP ho\u1eb7c s\u1eed d\u1ee5ng l\u1ea1i k\u1ebft n\u1ed1i \u0111\u00f3 cho c\u00e1c y\u00eau c\u1ea7u trong t\u01b0\u01a1ng lai.\u00a0<\/li>\n\n\n\n<li>N\u1ebfu d\u1eef li\u1ec7u ph\u1ea3n h\u1ed3i c\u00f3 th\u1ec3 l\u01b0u v\u00e0o b\u1ed9 nh\u1edb \u0111\u1ec7m th\u00ec tr\u00ecnh duy\u1ec7t c\u0169ng s\u1ebd l\u01b0u v\u00e0o b\u1ed9 nh\u1edb \u0111\u1ec7m d\u1eef li\u1ec7u \u0111\u00f3.\u00a0<\/li>\n\n\n\n<li>Tr\u00ecnh duy\u1ec7t gi\u1ea3i m\u00e3 ph\u1ea3n h\u1ed3i v\u00e0 hi\u1ec3n th\u1ecb n\u1ed9i dung.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-24-gi\u1ea3i-thich-cach-tri\u1ec3n-khai-va-kh\u1eafc-ph\u1ee5c-s\u1ef1-c\u1ed1-d\u1ecbnh-tuy\u1ebfn-bgp-lam-th\u1ebf-nao-d\u1ec3-b\u1ea3o-m\u1eadt-cac-phien-bgp-nbsp\"><strong>24. Gi\u1ea3i th\u00edch c\u00e1ch tri\u1ec3n khai v\u00e0 kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 \u0111\u1ecbnh tuy\u1ebfn BGP. L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 b\u1ea3o m\u1eadt c\u00e1c phi\u00ean BGP?&nbsp;<\/strong><\/h3>\n\n\n\n<p>BGP l\u00e0 vi\u1ebft t\u1eaft c\u1ee7a Border Gateway Protocol, ch\u1ecbu tr\u00e1ch nhi\u1ec7m trao \u0111\u1ed5i th\u00f4ng tin \u0111\u1ecbnh tuy\u1ebfn tr\u1ef1c tuy\u1ebfn gi\u1eefa c\u00e1c h\u1ec7 th\u1ed1ng t\u1ef1 tr\u1ecb (AS). BGP s\u1eed d\u1ee5ng c\u00e1c thu\u1ed9c t\u00ednh path \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh tuy\u1ebfn \u0111\u01b0\u1eddng t\u1ed1t nh\u1ea5t. \u0110\u1ec3 tri\u1ec3n khai BGP, t\u00f4i c\u1ea5u h\u00ecnh c\u00e1c BGP peer, ch\u1ec9 \u0111\u1ecbnh s\u1ed1 h\u1ec7 th\u1ed1ng t\u1ef1 ch\u1ee7 v\u00e0 qu\u1ea3ng c\u00e1o m\u1ea1ng.&nbsp;<\/p>\n\n\n\n<p>Kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 BGP b\u1eb1ng c\u00e1ch ki\u1ec3m tra peer status, qu\u1ea3ng c\u00e1o router v\u00e0 b\u1ea3ng BGP. C\u00e1c l\u1ec7nh nh\u01b0 &#8216;show ip BGP&#8217;, &#8216;show ip BGP summary&#8217; v\u00e0 `debug ip bgp` r\u1ea5t h\u1eefu \u00edch. B\u1ea3o m\u1eadt c\u00e1c phi\u00ean BGP b\u1eb1ng c\u00e1c k\u1ef9 thu\u1eadt nh\u01b0 x\u00e1c th\u1ef1c BGP MD5 \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o r\u1eb1ng c\u00e1c b\u1ea3n c\u1eadp nh\u1eadt BGP \u0111\u1ebfn t\u1eeb c\u00e1c \u0111\u1ed1i t\u00e1c h\u1ee3p ph\u00e1p v\u00e0 \u00e1p d\u1ee5ng prefix filter \u0111\u1ec3 ng\u0103n ch\u1eb7n vi\u1ec7c qu\u1ea3ng c\u00e1o c\u00e1c router kh\u00f4ng ch\u00ednh x\u00e1c.<\/p>\n\n\n\n<p>C\u00e1c k\u1ef9 thu\u1eadt b\u1ea3o m\u1eadt BGP ti\u00ean ti\u1ebfn bao g\u1ed3m:<\/p>\n\n\n\n<p><strong>1. RPKI (Resource Public Key Infrastructure):<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>H\u1ec7 th\u1ed1ng x\u00e1c th\u1ef1c d\u1ef1a tr\u00ean ch\u1ee9ng ch\u1ec9 \u0111\u1ec3 x\u00e1c minh quy\u1ec1n s\u1edf h\u1eefu prefix;<\/li>\n\n\n\n<li>H\u1ed7 tr\u1ee3 ROA (Route Origin Authorization) \u0111\u1ec3 x\u00e1c minh AS \u0111\u00fang \u0111ang qu\u1ea3ng c\u00e1o prefix;<\/li>\n\n\n\n<li>Gi\u00fap ng\u0103n ch\u1eb7n BGP hijacking v\u00e0 route leaks.<\/li>\n<\/ul>\n\n\n\n<p><strong>2. BGP FlowSpec:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Cho ph\u00e9p tri\u1ec3n khai c\u00e1c filter d\u1ef1a tr\u00ean lu\u1ed3ng \u0111\u1ec3 ch\u1ed1ng DDoS;<\/li>\n\n\n\n<li>C\u00f3 th\u1ec3 \u0111\u1ecbnh ngh\u0129a v\u00e0 tri\u1ec3n khai c\u00e1c quy t\u1eafc l\u1ecdc chi ti\u1ebft tr\u00ean to\u00e0n m\u1ea1ng.<\/li>\n<\/ul>\n\n\n\n<p><strong>3. BGPSEC:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>M\u1edf r\u1ed9ng c\u1ee7a BGP \u0111\u1ec3 x\u00e1c th\u1ef1c to\u00e0n b\u1ed9 \u0111\u01b0\u1eddng \u0111i (path) thay v\u00ec ch\u1ec9 origin;<\/li>\n\n\n\n<li>S\u1eed d\u1ee5ng m\u1eadt m\u00e3 \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o t\u00ednh to\u00e0n v\u1eb9n c\u1ee7a chu\u1ed7i AS-PATH.<\/li>\n<\/ul>\n\n\n\n<p><strong>4. TTL Security (GTSM &#8211; Generalized TTL Security Mechanism):<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u0110\u1eb7t gi\u00e1 tr\u1ecb TTL cao khi\u1ebfn c\u00e1c g\u00f3i tin t\u1eeb xa kh\u00f4ng th\u1ec3 \u0111\u1ea1t \u0111\u1ebfn router;<\/li>\n\n\n\n<li>B\u1ea3o v\u1ec7 hi\u1ec7u qu\u1ea3 ch\u1ed1ng l\u1ea1i c\u00e1c cu\u1ed9c t\u1ea5n c\u00f4ng t\u1eeb xa.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-25-b\u1ea1n-da-t\u1eebng-x\u1eed-ly-s\u1ef1-c\u1ed1-m\u1ea1ng-nghiem-tr\u1ecdng-trong-tinh-hu\u1ed1ng-ap-l\u1ef1c-cao-ch\u01b0a-hay-mo-t\u1ea3-cach-b\u1ea1n-gi\u1ea3i-quy\u1ebft-va-nh\u1eefng-bai-h\u1ecdc-rut-ra\"><strong>25. B\u1ea1n \u0111\u00e3 t\u1eebng x\u1eed l\u00fd s\u1ef1 c\u1ed1 m\u1ea1ng nghi\u00eam tr\u1ecdng trong t\u00ecnh hu\u1ed1ng \u00e1p l\u1ef1c cao ch\u01b0a? H\u00e3y m\u00f4 t\u1ea3 c\u00e1ch b\u1ea1n gi\u1ea3i quy\u1ebft v\u00e0 nh\u1eefng b\u00e0i h\u1ecdc r\u00fat ra.<\/strong><\/h3>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>L\u01b0u \u00fd: Sau \u0111\u00e2y l\u00e0 v\u00ed d\u1ee5 v\u1ec1 m\u1eabu c\u00e2u tr\u1ea3 l\u1eddi m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o, h\u00e3y tr\u1ea3 l\u1eddi theo kinh nghi\u1ec7m c\u00e1 nh\u00e2n.<\/p>\n<\/blockquote>\n\n\n\n<p>T\u00f4i t\u1eebng \u0111\u1ed1i m\u1eb7t v\u1edbi s\u1ef1 c\u1ed1 m\u1ea5t m\u1ea1ng nghi\u00eam tr\u1ecdng do b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh sai trong gi\u1edd cao \u0111i\u1ec3m. T\u00f4i \u0111\u00e3 nhanh ch\u00f3ng \u0111\u00e1nh gi\u00e1 t\u00ecnh h\u00ecnh v\u00e0 s\u1eed d\u1ee5ng c\u00e1c c\u00f4ng c\u1ee5 gi\u00e1m s\u00e1t m\u1ea1ng \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh v\u1ea5n \u0111\u1ec1. Sau \u0111\u00f3, t\u00f4i c\u1ea5u h\u00ecnh l\u1ea1i b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn v\u00e0 tri\u1ec3n khai gi\u1ea3i ph\u00e1p chuy\u1ec3n \u0111\u1ed5i d\u1ef1 ph\u00f2ng \u0111\u1ec3 kh\u00f4i ph\u1ee5c d\u1ecbch v\u1ee5 trong v\u00f2ng 30 ph\u00fat. Sau \u0111\u00f3, t\u00f4i c\u1ea3i ti\u1ebfn quy tr\u00ecnh thay \u0111\u1ed5i b\u1eb1ng c\u00e1ch th\u00eam b\u01b0\u1edbc ki\u1ec3m th\u1eed v\u00e0 ph\u00ea duy\u1ec7t k\u1ef9 h\u01a1n. Tr\u1ea3i nghi\u1ec7m n\u00e0y \u0111\u00e3 d\u1ea1y cho t\u00f4i t\u1ea7m quan tr\u1ecdng c\u1ee7a vi\u1ec7c gi\u1eef b\u00ecnh t\u0129nh d\u01b0\u1edbi \u00e1p l\u1ef1c v\u00e0 c\u00f3 quy tr\u00ecnh kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 r\u00f5 r\u00e0ng.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-26-lam-th\u1ebf-nao-d\u1ec3-t\u1ed1i-\u01b0u-hoa-cac-vung-ospf-nbsp\"><strong>26. L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 t\u1ed1i \u01b0u h\u00f3a c\u00e1c v\u00f9ng OSPF?<\/strong>&nbsp;<\/h3>\n\n\n\n<p>T\u00f4i t\u1ed1i \u01b0u h\u00f3a c\u00e1c v\u00f9ng OSPF b\u1eb1ng c\u00e1c c\u00e1ch:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>S\u1eed d\u1ee5ng c\u00e1c lo\u1ea1i v\u00f9ng th\u00edch h\u1ee3p (v\u00ed d\u1ee5: backbone area, stub area, not-so-stubby area) \u0111\u1ec3 qu\u1ea3n l\u00fd th\u00f4ng tin \u0111\u1ecbnh tuy\u1ebfn.\u00a0<\/li>\n\n\n\n<li>Tri\u1ec3n khai t\u00f3m t\u1eaft \u0111\u1ec3 gi\u1ea3m k\u00edch th\u01b0\u1edbc b\u1ea3ng \u0111\u1ecbnh tuy\u1ebfn.\u00a0<\/li>\n\n\n\n<li>\u0110i\u1ec1u ch\u1ec9nh chi ph\u00ed v\u00e0 s\u1ed1 li\u1ec7u OSPF \u0111\u1ec3 t\u00e1c \u0111\u1ed9ng \u0111\u1ebfn vi\u1ec7c l\u1ef1a ch\u1ecdn \u0111\u01b0\u1eddng d\u1eabn.<\/li>\n\n\n\n<li>S\u1eed d\u1ee5ng x\u00e1c th\u1ef1c MD5 ho\u1eb7c SHA cho c\u00e1c adjacency OSPF.<\/li>\n\n\n\n<li>Tri\u1ec3n khai TTL security \u0111\u1ec3 ng\u0103n ch\u1eb7n c\u00e1c cu\u1ed9c t\u1ea5n c\u00f4ng t\u1eeb xa.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-27-nh\u1eefng-l\u01b0u-y-quan-tr\u1ecdng-khi-l\u1eadp-k\u1ebf-ho\u1ea1ch-ph\u1ee5c-h\u1ed3i-sau-th\u1ea3m-h\u1ecda-m\u1ea1ng-la-gi-nbsp\"><strong>27. Nh\u1eefng l\u01b0u \u00fd quan tr\u1ecdng khi l\u1eadp k\u1ebf ho\u1ea1ch ph\u1ee5c h\u1ed3i sau th\u1ea3m h\u1ecda m\u1ea1ng l\u00e0 g\u00ec?&nbsp;<\/strong><\/h3>\n\n\n\n<p>K\u1ebf ho\u1ea1ch DR (Disaster Recovery) c\u1ea7n x\u00e1c \u0111\u1ecbnh r\u00f5 <strong>RPO<\/strong> (m\u1ee9c m\u1ea5t d\u1eef li\u1ec7u ch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c) v\u00e0 <strong>RTO<\/strong> (th\u1eddi gian kh\u00f4i ph\u1ee5c t\u1ed1i \u0111a cho ph\u00e9p).<br>Ngo\u00e0i ra, c\u1ea7n l\u01b0u \u00fd c\u00e1c y\u1ebfu t\u1ed1 quan tr\u1ecdng nh\u01b0:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>D\u1ef1 ph\u00f2ng \u0111a l\u1edbp: ph\u1ea7n c\u1ee9ng, \u0111\u01b0\u1eddng truy\u1ec1n v\u00e0 v\u1ecb tr\u00ed \u0111\u1ecba l\u00fd.<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Thi\u1ebft l\u1eadp v\u00e0 ki\u1ec3m tra c\u00e1c giao th\u1ee9c sao l\u01b0u v\u00e0 kh\u00f4i ph\u1ee5c d\u1eef li\u1ec7u th\u01b0\u1eddng xuy\u00ean.\u00a0<\/li>\n\n\n\n<li>Tri\u1ec3n khai c\u00e1c c\u01a1 ch\u1ebf chuy\u1ec3n \u0111\u1ed5i d\u1ef1 ph\u00f2ng t\u1ef1 \u0111\u1ed9ng \u0111\u1ec3 gi\u1ea3m thi\u1ec3u s\u1ef1 can thi\u1ec7p th\u1ee7 c\u00f4ng.<\/li>\n\n\n\n<li>Ghi ch\u00e9p \u0111\u1ea7y \u0111\u1ee7, d\u1ec5 ti\u1ebfp c\u1eadn \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o k\u1ebf ho\u1ea1ch c\u00f3 hi\u1ec7u qu\u1ea3.<\/li>\n\n\n\n<li>C\u00e1c gi\u1ea3i ph\u00e1p ph\u1ee5c h\u1ed3i sau th\u1ea3m h\u1ecda d\u1ef1a tr\u00ean \u0111\u00e1m m\u00e2y cung c\u1ea5p kh\u1ea3 n\u0103ng m\u1edf r\u1ed9ng v\u00e0 linh ho\u1ea1t h\u01a1n.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-28-s\u1ef1-khac-nhau-gi\u1eefa-ipconfig-va-ifconfig-la-gi-nbsp\"><strong>28. S\u1ef1 kh\u00e1c nhau gi\u1eefa ipconfig v\u00e0 ifconfig l\u00e0 g\u00ec?<\/strong>&nbsp;<\/h3>\n\n\n\n<p>C\u1ea3 ipconfig v\u00e0 ifconfig \u0111\u1ec1u l\u00e0 l\u1ec7nh d\u00f9ng \u0111\u1ec3 xem v\u00e0 c\u1ea5u h\u00ecnh c\u00e1c th\u00f4ng tin m\u1ea1ng (l\u1ea5y TCP\/IP summary v\u00e0 cho ph\u00e9p thay \u0111\u1ed5i c\u00e0i \u0111\u1eb7t DHCP v\u00e0 DNS), nh\u01b0ng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng tr\u00ean c\u00e1c h\u1ec7 \u0111i\u1ec1u h\u00e0nh kh\u00e1c nhau:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>ipconfig l\u00e0 l\u1ec7nh d\u00e0nh cho h\u1ec7 \u0111i\u1ec1u h\u00e0nh Windows, d\u00f9ng \u0111\u1ec3 hi\u1ec3n th\u1ecb th\u00f4ng tin c\u1ea5u h\u00ecnh TCP\/IP v\u00e0 cho ph\u00e9p l\u00e0m m\u1edbi \u0111\u1ecba ch\u1ec9 IP, c\u00e0i \u0111\u1eb7t DNS, DHCP,&#8230;<br><\/li>\n\n\n\n<li>ifconfig l\u00e0 l\u1ec7nh d\u00e0nh cho c\u00e1c h\u1ec7 \u0111i\u1ec1u h\u00e0nh Linux, macOS, UNIX, d\u00f9ng \u0111\u1ec3 c\u1ea5u h\u00ecnh v\u00e0 qu\u1ea3n l\u00fd c\u00e1c giao di\u1ec7n m\u1ea1ng nh\u01b0 g\u00e1n \u0111\u1ecba ch\u1ec9 IP, b\u1eadt\/t\u1eaft giao di\u1ec7n,\u2026\u00a0<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-29-lam-th\u1ebf-nao-d\u1ec3-b\u1ea3o-v\u1ec7-m\u1ea1ng-ch\u1ed1ng-l\u1ea1i-cac-cu\u1ed9c-t\u1ea5n-cong-ddos-nbsp\"><strong>29. L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 b\u1ea3o v\u1ec7 m\u1ea1ng ch\u1ed1ng l\u1ea1i c\u00e1c cu\u1ed9c t\u1ea5n c\u00f4ng DDoS?<\/strong>&nbsp;<\/h3>\n\n\n\n<p>Ph\u00f2ng th\u1ee7 ch\u1ed1ng l\u1ea1i c\u00e1c cu\u1ed9c t\u1ea5n c\u00f4ng DDoS (Distributed Denial of Service) \u0111\u00f2i h\u1ecfi m\u1ed9t ph\u01b0\u01a1ng ph\u00e1p ti\u1ebfp c\u1eadn nhi\u1ec1u layer:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Gi\u1edbi h\u1ea1n s\u1ed1 l\u01b0\u1ee3ng y\u00eau c\u1ea7u t\u1eeb m\u1ed9t ngu\u1ed3n (IP) c\u1ee5 th\u1ec3.\u00a0<\/li>\n\n\n\n<li>L\u1ecdc traffic b\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng ACL v\u00e0 BGP flowspec \u0111\u1ec3 ch\u1eb7n c\u00e1c m\u1eabu traffic \u0111\u1ed9c h\u1ea1i.\u00a0<\/li>\n\n\n\n<li>H\u1ec7 th\u1ed1ng ph\u00e1t hi\u1ec7n\/ng\u0103n ch\u1eb7n x\u00e2m nh\u1eadp (IDS\/IPS) gi\u00fap x\u00e1c \u0111\u1ecbnh v\u00e0 ch\u1eb7n c\u00e1c signature t\u1ea5n c\u00f4ng.\u00a0<\/li>\n<\/ul>\n\n\n\n<p>C\u00e1c d\u1ecbch v\u1ee5 gi\u1ea3m thi\u1ec3u DDoS, d\u00f9 l\u00e0 tr\u00ean n\u1ec1n t\u1ea3ng \u0111\u00e1m m\u00e2y hay t\u1ea1i ch\u1ed7, c\u00f3 th\u1ec3 h\u1ea5p th\u1ee5 kh\u1ed1i l\u01b0\u1ee3ng l\u1edbn l\u01b0u l\u01b0\u1ee3ng t\u1ea5n c\u00f4ng. Vi\u1ec7c c\u1ea5p ph\u00e1t d\u01b0 th\u1eeba b\u0103ng th\u00f4ng s\u1ebd cung c\u1ea5p th\u00eam dung l\u01b0\u1ee3ng. S\u1eed d\u1ee5ng CDN ph\u00e2n ph\u1ed1i l\u01b0u l\u01b0\u1ee3ng, khi\u1ebfn vi\u1ec7c qu\u00e1 t\u1ea3i m\u00e1y ch\u1ee7 g\u1ed1c tr\u1edf n\u00ean kh\u00f3 kh\u0103n h\u01a1n.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-30-mo-t\u1ea3-m\u1ed9t-s\u1ef1-c\u1ed1-m\u1ea1ng-ph\u1ee9c-t\u1ea1p-ma-b\u1ea1n-da-gi\u1ea3i-quy\u1ebft-va-cac-b\u01b0\u1edbc-b\u1ea1n-da-th\u1ef1c-hi\u1ec7n-d\u1ec3-kh\u1eafc-ph\u1ee5c-s\u1ef1-c\u1ed1-nbsp\"><strong>30. M\u00f4 t\u1ea3 m\u1ed9t s\u1ef1 c\u1ed1 m\u1ea1ng ph\u1ee9c t\u1ea1p m\u00e0 b\u1ea1n \u0111\u00e3 gi\u1ea3i quy\u1ebft v\u00e0 c\u00e1c b\u01b0\u1edbc b\u1ea1n \u0111\u00e3 th\u1ef1c hi\u1ec7n \u0111\u1ec3 kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1?<\/strong>&nbsp;<\/h3>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>L\u01b0u \u00fd: Sau \u0111\u00e2y l\u00e0 v\u00ed d\u1ee5 v\u1ec1 m\u1eabu c\u00e2u tr\u1ea3 l\u1eddi m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o, h\u00e3y tr\u1ea3 l\u1eddi theo kinh nghi\u1ec7m c\u00e1 nh\u00e2n.<\/p>\n<\/blockquote>\n\n\n\n<p>T\u00f4i t\u1eebng g\u1eb7p ph\u1ea3i c\u00e1c s\u1ef1 c\u1ed1 k\u1ebft n\u1ed1i kh\u00f4ng li\u00ean t\u1ee5c \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn ho\u1ea1t \u0111\u1ed9ng c\u1ee7a trung t\u00e2m d\u1eef li\u1ec7u. T\u00f4i \u0111\u00e3 d\u1eabn d\u1eaft qu\u00e1 tr\u00ecnh kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 v\u1edbi c\u00e1c b\u01b0\u1edbc nh\u01b0 sau:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u0110\u1ea7u ti\u00ean l\u00e0 ph\u00e2n t\u00edch nh\u1eadt k\u00fd v\u00e0 l\u01b0u l\u01b0\u1ee3ng m\u1ea1ng. T\u00f4i ph\u00e1t hi\u1ec7n ra m\u1ed9t b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn \u0111\u01b0\u1ee3c c\u1ea5u h\u00ecnh sai g\u00e2y m\u1ea5t packet.\u00a0<\/li>\n\n\n\n<li>Khi h\u1ee3p t\u00e1c v\u1edbi nh\u00f3m c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng, ch\u00fang t\u00f4i \u0111\u00e3 c\u1ea5u h\u00ecnh l\u1ea1i c\u00e0i \u0111\u1eb7t b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn v\u00e0 theo d\u00f5i k\u1ebft qu\u1ea3. \u0110i\u1ec1u n\u00e0y kh\u00f4ng ch\u1ec9 kh\u00f4i ph\u1ee5c k\u1ebft n\u1ed1i m\u00e0 c\u00f2n c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t m\u1ea1ng t\u1ed5ng th\u1ec3 l\u00ean 30%.\u00a0<\/li>\n<\/ul>\n\n\n\n<p>Kinh nghi\u1ec7m n\u00e0y \u0111\u00e3 d\u1ea1y cho t\u00f4i gi\u00e1 tr\u1ecb c\u1ee7a vi\u1ec7c ph\u00e2n t\u00edch k\u1ef9 l\u01b0\u1ee1ng v\u00e0 l\u00e0m vi\u1ec7c nh\u00f3m trong vi\u1ec7c gi\u1ea3i quy\u1ebft c\u00e1c s\u1ef1 c\u1ed1 ph\u1ee9c t\u1ea1p.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-31-m\u1ed9t-s\u1ed1-bi\u1ec7n-phap-th\u1ef1c-hanh-t\u1ed1t-nh\u1ea5t-cho-b\u1ea3o-m\u1eadt-m\u1ea1ng-khong-day-la-gi-nbsp\"><strong>31. M\u1ed9t s\u1ed1 bi\u1ec7n ph\u00e1p th\u1ef1c h\u00e0nh t\u1ed1t nh\u1ea5t cho b\u1ea3o m\u1eadt m\u1ea1ng kh\u00f4ng d\u00e2y l\u00e0 g\u00ec?&nbsp;<\/strong><\/h3>\n\n\n\n<p>B\u1ea3o m\u1eadt m\u1ea1ng kh\u00f4ng d\u00e2y l\u00e0 ch\u00eca kh\u00f3a \u0111\u1ec3 b\u1ea3o v\u1ec7 d\u1eef li\u1ec7u v\u00e0 h\u1ec7 th\u1ed1ng kh\u1ecfi truy c\u1eadp tr\u00e1i ph\u00e9p. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 bi\u1ec7n ph\u00e1p t\u00f4i th\u01b0\u1eddng \u00e1p d\u1ee5ng:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>S\u1eed d\u1ee5ng m\u00e3 h\u00f3a m\u1ea1nh (m\u00e3 h\u00f3a WPA2 v\u00e0 WPA3).\u00a0<\/li>\n\n\n\n<li>T\u1eaft ph\u00e1t s\u00f3ng SSID \u0111\u1ec3 gi\u1ea3m kh\u1ea3 n\u0103ng m\u1ea1ng b\u1ecb ph\u00e1t hi\u1ec7n b\u1edfi c\u00e1c thi\u1ebft b\u1ecb kh\u00f4ng mong mu\u1ed1n.<\/li>\n\n\n\n<li>L\u1ecdc \u0111\u1ecba ch\u1ec9 MAC ng\u0103n c\u00e1c thi\u1ebft b\u1ecb kh\u00e1c k\u1ebft n\u1ed1i v\u1edbi m\u1ea1ng.<\/li>\n\n\n\n<li>Tri\u1ec3n khai firewall \u0111\u1ec3 b\u1ed5 sung m\u1ed9t l\u1edbp b\u1ea3o v\u1ec7 th\u1ee9 hai nh\u1eb1m ki\u1ec3m so\u00e1t l\u01b0u l\u01b0\u1ee3ng ra v\u00e0o m\u1ea1ng.<\/li>\n\n\n\n<li>C\u1eadp nh\u1eadt firmware \u0111\u1ecbnh k\u1ef3 \u0111\u1ec3 lo\u1ea1i b\u1ecf c\u00e1c l\u1ed7 h\u1ed5ng b\u1ea3o m\u1eadt.\u00a0<\/li>\n\n\n\n<li>T\u00e1ch ri\u00eang guest network kh\u1ecfi m\u1ea1ng ch\u00ednh gi\u00fap ng\u0103n ch\u1eb7n vi\u1ec7c truy c\u1eadp v\u00f4 t\u00ecnh v\u00e0o c\u00e1c t\u00e0i nguy\u00ean quan tr\u1ecdng.\u00a0<\/li>\n\n\n\n<li>V\u00e0 t\u00f4i kh\u00f4ng bao gi\u1edd \u0111\u00e1nh gi\u00e1 th\u1ea5p t\u1ea7m quan tr\u1ecdng c\u1ee7a vi\u1ec7c ki\u1ec3m tra an ninh th\u01b0\u1eddng xuy\u00ean, th\u1ef1c hi\u1ec7n c\u00e1c b\u00e0i ki\u1ec3m th\u1eed x\u00e2m nh\u1eadp (penetration testing) \u0111\u1ecbnh k\u1ef3 \u0111\u1ec3 ph\u00e1t hi\u1ec7n v\u00e0 kh\u1eafc ph\u1ee5c k\u1ecbp th\u1eddi c\u00e1c \u0111i\u1ec3m y\u1ebfu trong h\u1ec7 th\u1ed1ng.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-32-gi\u1ea3i-thich-vi\u1ec7c-s\u1eed-d\u1ee5ng-ai-va-may-h\u1ecdc-trong-qu\u1ea3n-ly-m\u1ea1ng-nbsp\"><strong>32. Gi\u1ea3i th\u00edch vi\u1ec7c s\u1eed d\u1ee5ng AI v\u00e0 m\u00e1y h\u1ecdc trong qu\u1ea3n l\u00fd m\u1ea1ng.<\/strong>&nbsp;<\/h3>\n\n\n\n<p>AI v\u00e0 m\u00e1y h\u1ecdc (Machine Learning) \u0111ang bi\u1ebfn \u0111\u1ed5i c\u00e1ch qu\u1ea3n l\u00fd m\u1ea1ng b\u1eb1ng c\u00e1c kh\u1ea3 n\u0103ng sau:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>D\u1ef1 \u0111o\u00e1n s\u1ef1 c\u1ed1:<\/strong> Ph\u00e2n t\u00edch d\u1eef li\u1ec7u l\u1ecbch s\u1eed \u0111\u1ec3 d\u1ef1 \u0111o\u00e1n l\u01b0u l\u01b0\u1ee3ng v\u00e0 ph\u00e1t hi\u1ec7n s\u1edbm c\u00e1c r\u1ee7i ro ti\u1ec1m \u1ea9n.<\/li>\n\n\n\n<li><strong>Ph\u00e1t hi\u1ec7n b\u1ea5t th\u01b0\u1eddng:<\/strong> X\u00e1c \u0111\u1ecbnh h\u00e0nh vi m\u1ea1ng b\u1ea5t th\u01b0\u1eddng v\u00e0 c\u00e1c m\u1ed1i \u0111e d\u1ecda b\u1ea3o m\u1eadt b\u1eb1ng c\u00e1ch ph\u00e2n t\u00edch c\u00e1c m\u00f4 h\u00ecnh v\u00e0 \u0111\u1ed9 l\u1ec7ch so v\u1edbi h\u00e0nh vi b\u00ecnh th\u01b0\u1eddng.\u00a0<\/li>\n\n\n\n<li><strong>T\u1ef1 \u0111\u1ed9ng h\u00f3a:<\/strong> T\u1ef1 \u0111\u1ed9ng th\u1ef1c hi\u1ec7n c\u00e1c t\u00e1c v\u1ee5 th\u01b0\u1eddng xuy\u00ean nh\u01b0 thay \u0111\u1ed5i c\u1ea5u h\u00ecnh, t\u1ed1i \u01b0u h\u00f3a m\u1ea1ng v\u00e0 qu\u1ea3n l\u00fd l\u1ed7i.\u00a0<\/li>\n\n\n\n<li><strong>T\u1ed1i \u01b0u h\u00f3a hi\u1ec7u su\u1ea5t m\u1ea1ng:<\/strong> Ph\u00e2n t\u00edch th\u1eddi gian th\u1ef1c \u0111\u1ec3 \u0111i\u1ec1u ch\u1ec9nh t\u00e0i nguy\u00ean v\u00e0 c\u1ea5u h\u00ecnh m\u1ed9t c\u00e1ch linh ho\u1ea1t.<\/li>\n\n\n\n<li><strong>T\u1ef1 ph\u1ee5c h\u1ed3i:<\/strong> Tri\u1ec3n khai c\u01a1 ch\u1ebf t\u1ef1 ph\u1ee5c h\u1ed3i gi\u00fap t\u1ef1 \u0111\u1ed9ng gi\u1ea3i quy\u1ebft c\u00e1c s\u1ef1 c\u1ed1 m\u1ea1ng m\u00e0 kh\u00f4ng c\u1ea7n s\u1ef1 can thi\u1ec7p c\u1ee7a con ng\u01b0\u1eddi.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-33-s\u1eed-d\u1ee5ng-h\u1ec7-th\u1ed1ng-giam-sat-m\u1ea1ng-nms-co-l\u1ee3i-cho-b\u1ea1n-nh\u01b0-th\u1ebf-nao-nbsp\"><strong>33. S\u1eed d\u1ee5ng h\u1ec7 th\u1ed1ng gi\u00e1m s\u00e1t m\u1ea1ng NMS c\u00f3 l\u1ee3i cho b\u1ea1n nh\u01b0 th\u1ebf n\u00e0o?<\/strong>&nbsp;<\/h3>\n\n\n\n<p>C\u00f3 nhi\u1ec1u l\u1ee3i \u00edch khi s\u1eed d\u1ee5ng H\u1ec7 th\u1ed1ng gi\u00e1m s\u00e1t m\u1ea1ng (NMS &#8211; Network Monitoring System):<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Cho ph\u00e9p ph\u00e1t hi\u1ec7n ch\u1ee7 \u0111\u1ed9ng c\u00e1c s\u1ef1 c\u1ed1 c\u00f3 th\u1ec3 x\u1ea3y ra tr\u01b0\u1edbc khi ch\u00fang \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn ng\u01b0\u1eddi d\u00f9ng, b\u1eb1ng c\u00e1ch cung c\u1ea5p kh\u1ea3 n\u0103ng gi\u00e1m s\u00e1t t\u1eadp trung t\u1ea5t c\u1ea3 c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng v\u00e0 c\u00e1c bi\u1ec7n ph\u00e1p hi\u1ec7u su\u1ea5t.\u00a0<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Gi\u00fap \u0111\u01a1n gi\u1ea3n h\u00f3a vi\u1ec7c l\u1eadp k\u1ebf ho\u1ea1ch n\u0103ng l\u1ef1c, theo d\u00f5i c\u00e1c m\u00f4 h\u00ecnh t\u0103ng tr\u01b0\u1edfng v\u00e0 m\u1ee9c s\u1eed d\u1ee5ng b\u0103ng th\u00f4ng.\u00a0<\/li>\n\n\n\n<li>Gi\u00fap ph\u00e2n t\u00edch hi\u1ec7u su\u1ea5t to\u00e0n di\u1ec7n \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m ngh\u1ebdn v\u00e0 t\u0103ng c\u01b0\u1eddng hi\u1ec7u qu\u1ea3.\u00a0<\/li>\n\n\n\n<li>Cung c\u1ea5p nh\u1eadt k\u00fd chi ti\u1ebft v\u00e0 d\u1eef li\u1ec7u ch\u1ea9n \u0111o\u00e1n \u0111\u1ec3 h\u1ed7 tr\u1ee3 t\u00ecm l\u1ed7i.\u00a0<\/li>\n\n\n\n<li>C\u1ea3i thi\u1ec7n kh\u1ea3 n\u0103ng ph\u1ea3n h\u1ed3i v\u00e0 gi\u1ea3m b\u1ea3o tr\u00ec nh\u1edd t\u00ednh n\u0103ng b\u00e1o c\u00e1o t\u1ef1 \u0111\u1ed9ng cho c\u00e1c s\u1ef1 ki\u1ec7n quan tr\u1ecdng.\u00a0<\/li>\n\n\n\n<li>C\u1ea3i thi\u1ec7n kh\u1ea3 n\u0103ng hi\u1ec3n th\u1ecb, \u0111\u1ed9 tin c\u1eady v\u00e0 hi\u1ec7u qu\u1ea3 qu\u1ea3n l\u00fd m\u1ea1ng cu\u1ed1i c\u00f9ng.<\/li>\n<\/ul>\n\n\n\n<p>Ngo\u00e0i ra, c\u00e1c h\u1ec7 th\u1ed1ng NMS hi\u1ec7n \u0111\u1ea1i cung c\u1ea5p nhi\u1ec1u t\u00ednh n\u0103ng v\u00e0 l\u1ee3i \u00edch kh\u00e1c nh\u01b0:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Gi\u00e1m s\u00e1t th\u1eddi gian th\u1ef1c c\u00e1c metrics nh\u01b0 CPU, b\u1ed9 nh\u1edb, \u0111\u0129a v\u00e0 s\u1eed d\u1ee5ng b\u0103ng th\u00f4ng;<\/li>\n\n\n\n<li>Theo d\u00f5i t\u00ecnh tr\u1ea1ng thi\u1ebft b\u1ecb v\u00e0 d\u1ecbch v\u1ee5 v\u1edbi c\u00e1c ki\u1ec3m tra tr\u1ea1ng th\u00e1i;<\/li>\n\n\n\n<li>Ph\u00e1t hi\u1ec7n thay \u0111\u1ed5i c\u1ea5u h\u00ecnh v\u00e0 compliance monitoring;<\/li>\n\n\n\n<li>Ph\u00e2n t\u00edch xu h\u01b0\u1edbng d\u00e0i h\u1ea1n \u0111\u1ec3 d\u1ef1 b\u00e1o nhu c\u1ea7u v\u1ec1 t\u00e0i nguy\u00ean;<\/li>\n\n\n\n<li>B\u00e1o c\u00e1o SLA (Service Level Agreement) \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o tu\u00e2n th\u1ee7 c\u00e1c th\u1ecfa thu\u1eadn d\u1ecbch v\u1ee5;<\/li>\n\n\n\n<li>Ph\u00e2n t\u00edch flow-based (NetFlow, sFlow, IPFIX) cung c\u1ea5p th\u00f4ng tin chi ti\u1ebft v\u1ec1 l\u01b0u l\u01b0\u1ee3ng m\u1ea1ng.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-34-b\u1ea1n-x\u1eed-ly-multicast-routing-nh\u01b0-th\u1ebf-nao-trong-m\u1ed9t-network-r\u1ed9ng-l\u1edbn-nbsp\"><strong>34. B\u1ea1n x\u1eed l\u00fd multicast routing nh\u01b0 th\u1ebf n\u00e0o trong m\u1ed9t network r\u1ed9ng l\u1edbn?<\/strong>&nbsp;<\/h3>\n\n\n\n<p>X\u1eed l\u00fd multicast routing b\u1eb1ng c\u00e1c protocol nh\u01b0 PIM \u0111\u1ec3 qu\u1ea3n l\u00fd t\u01b0 c\u00e1ch th\u00e0nh vi\u00ean nh\u00f3m \u0111a h\u01b0\u1edbng v\u00e0 \u0111\u1ecbnh tuy\u1ebfn l\u01b0u l\u01b0\u1ee3ng \u0111a h\u01b0\u1edbng m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-35-mo-t\u1ea3-m\u1ed9t-ki\u1ebfn-truc-m\u1ea1ng-ph\u1ee9c-t\u1ea1p-ma-b\u1ea1n-da-thi\u1ebft-k\u1ebf-va-tri\u1ec3n-khai-k\u1ebft-qu\u1ea3-nh\u01b0-th\u1ebf-nao-va-co-thach-th\u1ee9c-gi-khong\"><strong>35. M\u00f4 t\u1ea3 m\u1ed9t ki\u1ebfn \u200b\u200btr\u00fac m\u1ea1ng ph\u1ee9c t\u1ea1p m\u00e0 b\u1ea1n \u0111\u00e3 thi\u1ebft k\u1ebf v\u00e0 tri\u1ec3n khai, k\u1ebft qu\u1ea3 nh\u01b0 th\u1ebf n\u00e0o v\u00e0 c\u00f3 th\u00e1ch th\u1ee9c g\u00ec kh\u00f4ng?<\/strong><\/h3>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>L\u01b0u \u00fd: Sau \u0111\u00e2y l\u00e0 v\u00ed d\u1ee5 v\u1ec1 m\u1eabu c\u00e2u tr\u1ea3 l\u1eddi m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o, h\u00e3y tr\u1ea3 l\u1eddi theo kinh nghi\u1ec7m c\u00e1 nh\u00e2n.<\/p>\n<\/blockquote>\n\n\n\n<p>T\u00f4i \u0111\u00e3 thi\u1ebft k\u1ebf m\u1ed9t ki\u1ebfn \u200b\u200btr\u00fac m\u1ea1ng \u0111a trang web cho m\u1ed9t kh\u00e1ch h\u00e0ng c\u00f3 y\u00eau c\u1ea7u v\u1ec1 t\u00ednh kh\u1ea3 d\u1ee5ng cao. Th\u00e1ch th\u1ee9c l\u1edbn nh\u1ea5t l\u00e0 l\u00e0m sao \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o khi m\u1ed9t site g\u1eb7p s\u1ef1 c\u1ed1, c\u00e1c k\u1ebft n\u1ed1i v\u1eabn ho\u1ea1t \u0111\u1ed9ng b\u00ecnh th\u01b0\u1eddng m\u00e0 ng\u01b0\u1eddi d\u00f9ng g\u1ea7n nh\u01b0 kh\u00f4ng nh\u1eadn ra. T\u00f4i \u0111\u00e3 k\u1ebft h\u1ee3p MPLS cho c\u00e1c \u1ee9ng d\u1ee5ng quan tr\u1ecdng c\u1ea7n \u0111\u1ed9 \u1ed5n \u0111\u1ecbnh cao v\u1edbi SD-WAN \u0111\u1ec3 t\u1ed1i \u01b0u chi ph\u00ed v\u00e0 t\u0103ng \u0111\u1ed9 linh ho\u1ea1t cho c\u00e1c k\u1ebft n\u1ed1i c\u00f2n l\u1ea1i.<\/p>\n\n\n\n<p>K\u1ebft qu\u1ea3 l\u00e0 th\u1eddi gian downtime \u0111\u01b0\u1ee3c gi\u1ea3m h\u01a1n 90%, v\u00e0 qu\u00e1 tr\u00ecnh failover di\u1ec5n ra g\u1ea7n nh\u01b0 t\u1ee9c th\u00ec. Ngo\u00e0i ra, vi\u1ec7c c\u00f3 th\u1ec3 theo d\u00f5i v\u00e0 \u0111i\u1ec1u ch\u1ec9nh ch\u00ednh s\u00e1ch m\u1ea1ng theo th\u1eddi gian th\u1ef1c qua SD-WAN gi\u00fap \u0111\u1ed9i v\u1eadn h\u00e0nh ph\u1ea3n \u1ee9ng nhanh h\u01a1n v\u1edbi s\u1ef1 c\u1ed1. Kh\u00e1ch h\u00e0ng b\u00e1o c\u00e1o r\u1eb1ng hi\u1ec7u qu\u1ea3 ho\u1ea1t \u0111\u1ed9ng v\u00e0 s\u1ef1 h\u00e0i l\u00f2ng c\u1ee7a kh\u00e1ch h\u00e0ng t\u0103ng \u0111\u00e1ng k\u1ec3 do \u0111\u1ed9 tin c\u1eady c\u1ee7a m\u1ea1ng \u0111\u01b0\u1ee3c n\u00e2ng cao.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-36-mo-t\u1ea3-m\u1ed9t-s\u1ef1-c\u1ed1-m\u1ea5t-m\u1ea1ng-b\u1ea1n-da-qu\u1ea3n-ly-va-cach-b\u1ea1n-gi\u1ea3i-quy\u1ebft\"><strong>36. M\u00f4 t\u1ea3 m\u1ed9t s\u1ef1 c\u1ed1 m\u1ea5t m\u1ea1ng b\u1ea1n \u0111\u00e3 qu\u1ea3n l\u00fd v\u00e0 c\u00e1ch b\u1ea1n gi\u1ea3i quy\u1ebft.<\/strong><\/h3>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>L\u01b0u \u00fd: Sau \u0111\u00e2y l\u00e0 v\u00ed d\u1ee5 v\u1ec1 m\u1eabu c\u00e2u tr\u1ea3 l\u1eddi m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o, h\u00e3y tr\u1ea3 l\u1eddi theo kinh nghi\u1ec7m c\u00e1 nh\u00e2n.<\/p>\n<\/blockquote>\n\n\n\n<p>T\u00f4i \u0111\u00e3 tr\u1ea3i qua m\u1ed9t s\u1ef1 c\u1ed1 m\u1ea5t m\u1ea1ng l\u1edbn \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn h\u01a1n 10.000 kh\u00e1ch h\u00e0ng. T\u00f4i \u0111\u00e3 nhanh ch\u00f3ng t\u1eadp h\u1ee3p nh\u00f3m k\u1ef9 thu\u1eadt v\u00e0 c\u00e1c b\u1ed9 ph\u1eadn li\u00ean quan \u0111\u1ec3 \u0111\u00e1nh gi\u00e1 t\u00ecnh h\u00ecnh. Ch\u00fang t\u00f4i x\u00e1c \u0111\u1ecbnh nguy\u00ean nh\u00e2n l\u00e0 c\u00f3 m\u1ed9t c\u1ea5u h\u00ecnh sai trong giao th\u1ee9c \u0111\u1ecbnh tuy\u1ebfn c\u1ee7a m\u00ecnh. Sau khi x\u00e1c \u0111\u1ecbnh nguy\u00ean nh\u00e2n, ch\u00fang t\u00f4i ph\u1ed1i h\u1ee3p tri\u1ec3n khai b\u1ea3n v\u00e1 trong v\u00f2ng kho\u1ea3ng 2 ti\u1ebfng \u0111\u1ec3 kh\u00f4i ph\u1ee5c k\u1ebft n\u1ed1i. \u0110\u1ed3ng th\u1eddi, t\u00f4i \u0111\u1ea3m b\u1ea3o c\u1eadp nh\u1eadt minh b\u1ea1ch cho kh\u00e1ch h\u00e0ng b\u1ecb \u1ea3nh h\u01b0\u1edfng trong su\u1ed1t qu\u00e1 tr\u00ecnh x\u1eed l\u00fd, gi\u00fap h\u1ecd y\u00ean t\u00e2m h\u01a1n.<\/p>\n\n\n\n<p>Sau s\u1ef1 c\u1ed1, t\u00f4i c\u00f9ng team \u0111\u00e3 r\u00e0 so\u00e1t l\u1ea1i to\u00e0n b\u1ed9 quy tr\u00ecnh qu\u1ea3n l\u00fd thay \u0111\u1ed5i, b\u1ed5 sung th\u00eam c\u00e1c b\u01b0\u1edbc ki\u1ec3m tra ch\u00e9o. Nh\u1edd v\u1eady, t\u1ef7 l\u1ec7 g\u1eb7p s\u1ef1 c\u1ed1 m\u1ea5t m\u1ea1ng t\u01b0\u01a1ng t\u1ef1 trong n\u0103m sau \u0111\u00e3 gi\u1ea3m \u0111\u00e1ng k\u1ec3 &#8211; kho\u1ea3ng 30%.&nbsp;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-t\u1ed5ng-k\u1ebft\"><span class=\"ez-toc-section\" id=\"Tong_ket\"><\/span><strong>T\u1ed5ng k\u1ebft<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>V\u1edbi b\u1ed9 c\u00e2u h\u1ecfi v\u00e0 g\u1ee3i \u00fd tr\u1ea3 l\u1eddi chi ti\u1ebft ITviec v\u1eeba chia s\u1ebb, c\u00e1c \u1ee9ng vi\u00ean Network Engineer s\u1ebd trang b\u1ecb th\u00eam s\u1ef1 t\u1ef1 tin v\u00e0 ki\u1ebfn th\u1ee9c v\u1eefng ch\u1eafc \u0111\u1ec3 chinh ph\u1ee5c m\u1ecdi nh\u00e0 tuy\u1ec3n d\u1ee5ng. H\u00e3y nh\u1edb r\u1eb1ng, s\u1ef1 chu\u1ea9n b\u1ecb k\u1ef9 l\u01b0\u1ee1ng v\u00e0 kh\u1ea3 n\u0103ng th\u1ec3 hi\u1ec7n b\u1ea3n th\u00e2n m\u1ed9t c\u00e1ch chuy\u00ean nghi\u1ec7p ch\u00ednh l\u00e0 ch\u00eca kh\u00f3a d\u1eabn \u0111\u1ebfn th\u00e0nh c\u00f4ng trong l\u0129nh v\u1ef1c \u0111\u1ea7y th\u1eed th\u00e1ch v\u00e0 c\u01a1 h\u1ed9i n\u00e0y.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>B\u1ea1n \u0111ang chu\u1ea9n b\u1ecb b\u01b0\u1edbc v\u00e0o v\u00f2ng ph\u1ecfng v\u1ea5n cho v\u1ecb tr\u00ed Network Engineer? B\u00e0i vi\u1ebft n\u00e0y s\u1ebd gi\u00fap b\u1ea1n t\u1ed5ng h\u1ee3p nh\u1eefng c\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer ph\u1ed5 bi\u1ebfn nh\u1ea5t, \u0111i k\u00e8m v\u1edbi g\u1ee3i \u00fd c\u00e1ch tr\u1ea3 l\u1eddi th\u00f4ng minh v\u00e0 hi\u1ec7u qu\u1ea3. C\u00f9ng kh\u00e1m ph\u00e1 nh\u1eefng c\u00e2u h\u1ecfi ph\u1ed5 bi\u1ebfn nh\u1ea5t v\u00e0 [&hellip;]<\/p>\n","protected":false},"author":205,"featured_media":88769,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_gspb_post_css":"","footnotes":""},"categories":[109,105,94],"tags":[],"class_list":["post-88761","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-chuyen-mon-it","category-phong-van-it","category-su-nghiep-it"],"blocksy_meta":[],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v26.8 (Yoast SEO v27.7) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>Top 30+ c\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer ph\u1ed5 bi\u1ebfn - ITviec Blog<\/title>\n<meta name=\"description\" content=\"H\u01b0\u1edbng d\u1eabn tr\u1ea3 l\u1eddi c\u00e1c c\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer ph\u1ed5 bi\u1ebfn, t\u1eeb c\u01a1 b\u1ea3n \u0111\u1ebfn c\u1ea5p cao, gi\u00fap b\u1ea1n \u00f4n t\u1eadp hi\u1ec7u qu\u1ea3 v\u00e0 t\u1ef1 tin khi ph\u1ecfng v\u1ea5n.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/itviec.com\/blog\/cau-hoi-phong-van-network-engineer\/\" \/>\n<meta property=\"og:locale\" content=\"vi_VN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Top 30+ c\u00e2u h\u1ecfi ph\u1ecfng v\u1ea5n Network Engineer ph\u1ed5 bi\u1ebfn\" \/>\n<meta property=\"og:description\" content=\"B\u1ea1n \u0111ang chu\u1ea9n b\u1ecb b\u01b0\u1edbc v\u00e0o v\u00f2ng ph\u1ecfng v\u1ea5n cho v\u1ecb tr\u00ed Network Engineer? 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