{"id":7278,"date":"2026-05-14T00:00:00","date_gmt":"2026-05-14T00:00:00","guid":{"rendered":"https:\/\/lp.szlogic.cn\/glossary\/what-is-frame-check-sequence-fcs\/"},"modified":"2026-06-22T03:25:59","modified_gmt":"2026-06-22T03:25:59","slug":"what-is-frame-check-sequence-fcs","status":"publish","type":"post","link":"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/what-is-frame-check-sequence-fcs","title":{"rendered":"D\u00e3y ki\u1ec3m tra khung (FCS): \u00dd ngh\u0129a, l\u1ed7i v\u00e0 c\u00e1ch kh\u1eafc ph\u1ee5c"},"content":{"rendered":"<figure class=\"wp-block-image aligncenter size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1200\" height=\"628\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/88484eaf1ed240fd919c40e0be49a046.jpg\" alt=\"Frame Check Sequence (FCS): Meaning, Errors, and Fixes\" class=\"wp-image-7268\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/88484eaf1ed240fd919c40e0be49a046.jpg 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/88484eaf1ed240fd919c40e0be49a046-300x157.jpg 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/88484eaf1ed240fd919c40e0be49a046-1024x536.jpg 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/88484eaf1ed240fd919c40e0be49a046-768x402.jpg 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/88484eaf1ed240fd919c40e0be49a046-18x9.jpg 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">D\u00e3y Ki\u1ec3m tra Khung (FCS) l\u00e0 m\u1ed9t c\u01a1 ch\u1ebf ph\u00e1t hi\u1ec7n l\u1ed7i \u1edf L\u1edbp 2 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong Ethernet v\u00e0 c\u00e1c giao th\u1ee9c truy\u1ec1n th\u00f4ng d\u1eef li\u1ec7u kh\u00e1c nh\u1eb1m x\u00e1c minh xem khung m\u1ea1ng c\u00f3 b\u1ecb h\u1ecfng trong qu\u00e1 tr\u00ecnh truy\u1ec1n hay kh\u00f4ng. Trong c\u00e1c m\u1ea1ng Ethernet hi\u1ec7n \u0111\u1ea1i, tr\u01b0\u1eddng FCS th\u01b0\u1eddng d\u1ef1a tr\u00ean CRC-32 v\u00e0 \u0111\u01b0\u1ee3c th\u00eam v\u00e0o cu\u1ed1i m\u1ed7i khung Ethernet \u0111\u1ec3 h\u1ed7 tr\u1ee3 c\u00e1c thi\u1ebft b\u1ecb nh\u01b0 b\u1ed9 chuy\u1ec3n m\u1ea1ch, b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn, m\u00e1y ch\u1ee7 v\u00e0 <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/what-is-nic-network-interface-card\/\">card giao di\u1ec7n m\u1ea1ng<\/a> (NIC) ph\u00e1t hi\u1ec7n l\u1ed7i truy\u1ec1n tr\u01b0\u1edbc khi d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c x\u1eed l\u00fd b\u1edfi c\u00e1c giao th\u1ee9c \u1edf l\u1edbp tr\u00ean.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong c\u00e1c m\u00f4i tr\u01b0\u1eddng m\u1ea1ng th\u1ef1c t\u1ebf, c\u00e1c l\u1ed7i FCS kh\u00f4ng ch\u1ec9 l\u00e0 nh\u1eefng s\u1ef1 ki\u1ec7n giao th\u1ee9c mang t\u00ednh l\u00fd thuy\u1ebft. Ch\u00fang th\u01b0\u1eddng l\u00e0 d\u1ea5u hi\u1ec7u c\u1ea3nh b\u00e1o s\u1edbm v\u1ec1 c\u00e1c v\u1ea5n \u0111\u1ec1 th\u1ef1c t\u1ebf \u1edf l\u1edbp v\u1eadt l\u00fd, bao g\u1ed3m c\u00e1p Ethernet b\u1ecb h\u01b0 h\u1ea1i, \u0111\u1ea7u n\u1ed1i s\u1ee3i quang b\u1ea9n, m\u00f4-\u0111un quang kh\u00f4ng \u1ed5n \u0111\u1ecbnh, <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/what-is-electromagnetic-interference\/\">nhi\u1ec5u \u0111i\u1ec7n t\u1eeb<\/a> (EMI), s\u1ef1 kh\u00f4ng kh\u1edbp duplex, ho\u1eb7c suy gi\u1ea3m \u0111\u1ed9 to\u00e0n v\u1eb9n t\u00edn hi\u1ec7u tr\u00ean c\u00e1c li\u00ean k\u1ebft t\u1ed1c \u0111\u1ed9 cao. Trong trung t\u00e2m d\u1eef li\u1ec7u v\u00e0 m\u1ea1ng doanh nghi\u1ec7p, c\u00e1c l\u1ed7i CRC\/FCS l\u1eb7p \u0111i l\u1eb7p l\u1ea1i th\u01b0\u1eddng li\u00ean quan \u0111\u1ebfn c\u00e1c b\u1ed9 thu ph\u00e1t quang l\u1ed7i v\u00e0 c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng c\u00e1p ch\u1ea5t l\u01b0\u1ee3ng k\u00e9m. <a target=\"_self\" href=\"https:\/\/www.l-p.com\/store-26155-1g-sfp.htm\">SFP<\/a>, <a target=\"_self\" href=\"https:\/\/www.l-p.com\/store-26192-10g-sfp.htm\">SFP+<\/a>, <a target=\"_self\" href=\"https:\/\/www.l-p.com\/store-26153-40g-qsfp.htm\">QSFP<\/a>, or <a target=\"_self\" href=\"https:\/\/www.l-p.com\/store-27045-100g-qsfp28-sfp-dd.htm\">QSFP28<br><\/a> b\u1ed9 thu ph\u00e1t quang v\u00e0 c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng c\u00e1p ch\u1ea5t l\u01b0\u1ee3ng k\u00e9m.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Khi t\u1ed1c \u0111\u1ed9 Ethernet ti\u1ebfp t\u1ee5c ph\u00e1t tri\u1ec3n t\u1eeb 1G v\u00e0 10G l\u00ean 100G, 400G v\u00e0 th\u1eadm ch\u00ed 800G Ethernet \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a theo c\u00e1c ti\u00eau chu\u1ea9n nh\u01b0 IEEE 802.3ck, vi\u1ec7c duy tr\u00ec \u0111\u1ed9 to\u00e0n v\u1eb9n khung ng\u00e0y c\u00e0ng tr\u1edf n\u00ean quan tr\u1ecdng. Ngay c\u1ea3 m\u1ed9t t\u1ef7 l\u1ec7 l\u1ed7i bit r\u1ea5t nh\u1ecf <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/understanding-what-is-bit-error-rate\/\">T\u1ef7 l\u1ec7 l\u1ed7i bit<\/a> (BER) c\u0169ng c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn h\u1ecfng g\u00f3i tin, truy\u1ec1n l\u1ea1i, t\u0103ng \u0111\u1ed9 tr\u1ec5 v\u00e0 m\u1ea5t \u1ed5n \u0111\u1ecbnh \u1ee9ng d\u1ee5ng. \u0110\u00e2y l\u00e0 l\u00fd do v\u00ec sao k\u1ef9 s\u01b0 m\u1ea1ng th\u01b0\u1eddng xuy\u00ean gi\u00e1m s\u00e1t c\u00e1c b\u1ed9 \u0111\u1ebfm FCS tr\u00ean b\u1ed9 chuy\u1ec3n m\u1ea1ch v\u00e0 c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng khi kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 m\u1ea5t g\u00f3i ho\u1eb7c c\u00e1c v\u1ea5n \u0111\u1ec1 k\u1ebft n\u1ed1i ng\u1eaft qu\u00e3ng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">B\u00e0i vi\u1ebft n\u00e0y gi\u1ea3i th\u00edch \u00fd ngh\u0129a c\u1ee7a D\u00e3y Ki\u1ec3m tra Khung (FCS), c\u00e1ch CRC-32 ho\u1ea1t \u0111\u1ed9ng b\u00ean trong khung Ethernet, l\u00fd do xu\u1ea5t hi\u1ec7n l\u1ed7i FCS, c\u0169ng nh\u01b0 m\u1ed1i li\u00ean h\u1ec7 gi\u1eefa ch\u00fang v\u1edbi <a target=\"_self\" href=\"https:\/\/www.l-p.com\/store-25432-optics-transceivers-sfp-modules.htm\">module quang<br><\/a> v\u00e0 c\u00e1c li\u00ean k\u1ebft s\u1ee3i quang, c\u00f9ng c\u00e1ch c\u00e1c chuy\u00ean gia m\u1ea1ng ch\u1ea9n \u0111o\u00e1n v\u00e0 kh\u1eafc ph\u1ee5c c\u00e1c v\u1ea5n \u0111\u1ec1 li\u00ean quan \u0111\u1ebfn CRC\/FCS trong c\u00e1c tri\u1ec3n khai th\u1ef1c t\u1ebf. \u0110\u1ebfn cu\u1ed1i h\u01b0\u1edbng d\u1eabn n\u00e0y, b\u1ea1n s\u1ebd hi\u1ec3u r\u00f5 c\u1ea3 n\u1ec1n t\u1ea3ng l\u00fd thuy\u1ebft l\u1eabn \u00fd ngh\u0129a v\u1eadn h\u00e0nh c\u1ee7a FCS trong c\u00e1c m\u1ea1ng Ethernet hi\u1ec7n \u0111\u1ea1i.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >\u2705 D\u00e3y Ki\u1ec3m tra Khung (FCS) l\u00e0 g\u00ec?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">D\u00e3y Ki\u1ec3m tra Khung (FCS) l\u00e0 tr\u01b0\u1eddng ph\u1ea7n \u0111u\u00f4i \u1edf cu\u1ed1i khung Ethernet, ch\u1ee9a gi\u00e1 tr\u1ecb CRC d\u00f9ng \u0111\u1ec3 ph\u00e1t hi\u1ec7n l\u1ed7i truy\u1ec1n. Trong <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/knowledge-center\/ieee-802-3-ethernet-standard-explained\/\">IEEE 802.3<\/a> c\u1ea5u tr\u00fac khung, tr\u01b0\u1eddng FCS d\u00e0i 4 byte v\u00e0 gi\u00fap thi\u1ebft b\u1ecb nh\u1eadn quy\u1ebft \u0111\u1ecbnh khung \u0111\u00f3 c\u00f2n nguy\u00ean v\u1eb9n hay \u0111\u00e3 b\u1ecb h\u1ecfng tr\u01b0\u1edbc khi ch\u1ea5p nh\u1eadn d\u1eef li\u1ec7u.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img decoding=\"async\" width=\"1200\" height=\"675\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/2549c701a33d4df493a36c7365132a8f.jpg\" alt=\"What Is Frame Check Sequence (FCS)?\" class=\"wp-image-7269\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/2549c701a33d4df493a36c7365132a8f.jpg 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/2549c701a33d4df493a36c7365132a8f-300x169.jpg 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/2549c701a33d4df493a36c7365132a8f-1024x576.jpg 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/2549c701a33d4df493a36c7365132a8f-768x432.jpg 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/2549c701a33d4df493a36c7365132a8f-18x10.jpg 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" >\u0110\u1ecbnh ngh\u0129a vi m\u00f4 v\u1ec1 FCS<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">FCS (D\u00e3y Ki\u1ec3m tra Khung) l\u00e0 m\u1ed9t tr\u01b0\u1eddng ph\u1ea7n \u0111u\u00f4i \u1edf L\u1edbp 2 \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 x\u00e1c minh \u0111\u1ed9 to\u00e0n v\u1eb9n c\u1ee7a khung Ethernet trong qu\u00e1 tr\u00ecnh truy\u1ec1n.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u1ecbnh ngh\u0129a \u0111\u01a1n gi\u1ea3n: FCS = Gi\u00e1 tr\u1ecb ki\u1ec3m tra l\u1ed7i \u0111\u01b0\u1ee3c g\u1eafn v\u00e0o cu\u1ed1i khung Ethernet<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u1ea5u tr\u00fac khung Ethernet \u0111\u01a1n gi\u1ea3n h\u00f3a:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>| Ti\u00eau \u0111\u1ec1 Ethernet | D\u1eef li\u1ec7u t\u1ea3i | FCS |<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">N\u1ebfu gi\u00e1 tr\u1ecb FCS nh\u1eadn \u0111\u01b0\u1ee3c kh\u00f4ng kh\u1edbp v\u1edbi gi\u00e1 tr\u1ecb \u0111\u01b0\u1ee3c t\u00ednh l\u1ea1i, khung s\u1ebd b\u1ecb lo\u1ea1i b\u1ecf.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >\u0110\u1ecbnh ngh\u0129a vi m\u00f4 v\u1ec1 CRC-32<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">CRC-32 (Ki\u1ec3m tra d\u01b0 v\u00f2ng 32 bit) l\u00e0 thu\u1eadt to\u00e1n to\u00e1n h\u1ecdc \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 t\u1ea1o ra gi\u00e1 tr\u1ecb FCS c\u1ee7a Ethernet.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong Ethernet:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">CRC-32CRCtext{-}32CRC-32<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Quy tr\u00ecnh c\u01a1 b\u1ea3n:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>D\u1eef li\u1ec7u khung \u2192 T\u00ednh to\u00e1n CRC-32 \u2192 FCS<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Ph\u00eda thi\u1ebft b\u1ecb nh\u1eadn:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>Khung nh\u1eadn \u0111\u01b0\u1ee3c \u2192 T\u00ednh l\u1ea1i CRC \u2192 So s\u00e1nh v\u1edbi FCS<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">CRC-32 r\u1ea5t hi\u1ec7u qu\u1ea3 trong vi\u1ec7c ph\u00e1t hi\u1ec7n:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>L\u1ed7i bit<\/p><\/li><li><p>L\u1ed7i c\u1ee5m (burst errors)<\/p><\/li><li><p>H\u1ecfng t\u00edn hi\u1ec7u<\/p><\/li><li><p>Nhi\u1ec5u truy\u1ec1n<\/p><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" >L\u00fd do FCS \u0111\u01b0\u1ee3c \u0111\u1eb7t \u1edf cu\u1ed1i khung<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">FCS \u0111\u01b0\u1ee3c \u0111\u1eb7t \u1edf cu\u1ed1i khung Ethernet v\u00ec ph\u00e9p t\u00ednh CRC ph\u1ea3i ho\u00e0n t\u1ea5t sau khi to\u00e0n b\u1ed9 d\u1eef li\u1ec7u khung \u0111\u00e3 \u0111\u01b0\u1ee3c x\u1eed l\u00fd.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Lu\u1ed3ng quy tr\u00ecnh:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>Khung \u0111\u01b0\u1ee3c t\u1ea1o \u2192 T\u00ednh CRC \u2192 G\u1eafn FCS<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Thi\u1ebft k\u1ebf n\u00e0y cho ph\u00e9p c\u00e1c thi\u1ebft b\u1ecb Ethernet x\u00e1c minh \u0111\u1ed9 to\u00e0n v\u1eb9n c\u1ee7a to\u00e0n b\u1ed9 khung tr\u01b0\u1edbc khi ch\u1ea5p nh\u1eadn d\u1eef li\u1ec7u.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong m\u1ea1ng th\u1ef1c t\u1ebf, c\u00e1c l\u1ed7i FCS l\u1eb7p \u0111i l\u1eb7p l\u1ea1i th\u01b0\u1eddng cho th\u1ea5y c\u00e1c v\u1ea5n \u0111\u1ec1 \u1edf l\u1edbp v\u1eadt l\u00fd, bao g\u1ed3m:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"width: 336px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\" colwidth=\"336\"><p>Nguy\u00ean nh\u00e2n ph\u1ed5 bi\u1ebfn<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>K\u1ebft qu\u1ea3 \u0111i\u1ec3n h\u00ecnh<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"336\"><p>C\u00e1p Ethernet b\u1ecb h\u01b0 h\u1ea1i<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>L\u1ed7i CRC\/FCS<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"336\"><p>\u0110\u1ea7u n\u1ed1i s\u1ee3i quang b\u1ea9n<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>H\u1ecfng g\u00f3i tin<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"336\"><p>M\u00f4-\u0111un quang SFP\/QSFP l\u1ed7i<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Ng\u1eaft qu\u00e3ng <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/what-does-packet-loss-mean-for-your-internet-connection\/\">m\u1ea5t g\u00f3i<\/a><\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"336\"><p>Nhi\u1ec5u \u0111i\u1ec7n t\u1eeb (EMI)<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>H\u1ecfng khung ng\u1eabu nhi\u00ean<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ec l\u00fd do n\u00e0y, c\u00e1c l\u1ed7i FCS \u0111\u01b0\u1ee3c c\u00e1c k\u1ef9 s\u01b0 m\u1ea1ng s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i nh\u01b0 m\u1ed9t ch\u1ec9 b\u00e1o s\u1edbm v\u1ec1 c\u00e1c v\u1ea5n \u0111\u1ec1 ch\u1ea5t l\u01b0\u1ee3ng li\u00ean k\u1ebft ho\u1eb7c b\u1ed9 thu ph\u00e1t quang.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >\u2705 FCS ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o trong c\u00e1c khung Ethernet?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Khi m\u1ed9t thi\u1ebft b\u1ecb g\u1eedi truy\u1ec1n m\u1ed9t khung Ethernet, n\u00f3 t\u00ednh to\u00e1n gi\u00e1 tr\u1ecb CRC tr\u00ean n\u1ed9i dung khung v\u00e0 ghi k\u1ebft qu\u1ea3 \u0111\u00f3 v\u00e0o tr\u01b0\u1eddng FCS. Thi\u1ebft b\u1ecb nh\u1eadn th\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh t\u01b0\u01a1ng t\u1ef1 r\u1ed3i so s\u00e1nh gi\u00e1 tr\u1ecb thu \u0111\u01b0\u1ee3c. N\u1ebfu hai gi\u00e1 tr\u1ecb kh\u1edbp nhau, khung \u0111\u01b0\u1ee3c ch\u1ea5p nh\u1eadn; n\u1ebfu kh\u00f4ng kh\u1edbp, khung b\u1ecb lo\u1ea1i b\u1ecf. \u0110\u00f3 l\u00e0 l\u00fd do v\u00ec sao FCS l\u00e0 m\u1ed9t ph\u00e9p ki\u1ec3m tra \u0111\u1ed9 to\u00e0n v\u1eb9n \u1edf L\u1edbp 2 di\u1ec5n ra r\u1ea5t nhanh.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img decoding=\"async\" width=\"1200\" height=\"675\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/92ab1a95487c4af99647400a6d08c0d9.jpg\" alt=\" How Does FCS Work in Ethernet Frames?\" class=\"wp-image-7270\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/92ab1a95487c4af99647400a6d08c0d9.jpg 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/92ab1a95487c4af99647400a6d08c0d9-300x169.jpg 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/92ab1a95487c4af99647400a6d08c0d9-1024x576.jpg 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/92ab1a95487c4af99647400a6d08c0d9-768x432.jpg 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/92ab1a95487c4af99647400a6d08c0d9-18x10.jpg 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Vi\u1ec7c x\u00e1c minh FCS x\u1ea3y ra ho\u00e0n to\u00e0n \u1edf L\u1edbp 2 v\u00e0 th\u01b0\u1eddng \u0111\u01b0\u1ee3c x\u1eed l\u00fd b\u1edfi ph\u1ea7n c\u1ee9ng Ethernet nh\u01b0 NIC, b\u1ed9 chuy\u1ec3n m\u1ea1ch <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/what-is-application-specific-integrated-circuit-asic\/\">IC chuy\u00ean d\u1ee5ng (ASIC)<\/a>, v\u00e0 giao di\u1ec7n quang. \u0110i\u1ec1u n\u00e0y cho ph\u00e9p ph\u00e1t hi\u1ec7n c\u00e1c khung b\u1ecb h\u1ecfng \u1edf t\u1ed1c \u0111\u1ed9 \u0111\u01b0\u1eddng d\u00e2y tr\u01b0\u1edbc khi ch\u00fang \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn c\u00e1c giao th\u1ee9c ho\u1eb7c \u1ee9ng d\u1ee5ng \u1edf l\u1edbp cao h\u01a1n.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Vi\u1ec7c t\u1ea1o CRC \u1edf ph\u00eda ng\u01b0\u1eddi g\u1eedi<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Tr\u01b0\u1edbc khi truy\u1ec1n m\u1ed9t khung Ethernet, thi\u1ebft b\u1ecb g\u1eedi t\u00ednh gi\u00e1 tr\u1ecb CRC-32 t\u1eeb d\u1eef li\u1ec7u khung.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Quy tr\u00ecnh c\u01a1 b\u1ea3n:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>D\u1eef li\u1ec7u khung Ethernet \u2192 T\u00ednh to\u00e1n CRC-32 \u2192 FCS \u0111\u01b0\u1ee3c t\u1ea1o<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Gi\u00e1 tr\u1ecb CRC \u0111\u01b0\u1ee3c t\u1ea1o ra sau \u0111\u00f3 \u0111\u01b0\u1ee3c g\u1eafn v\u00e0o cu\u1ed1i khung d\u01b0\u1edbi d\u1ea1ng tr\u01b0\u1eddng FCS.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Quy tr\u00ecnh khung Ethernet \u0111\u01a1n gi\u1ea3n h\u00f3a n\u00e0y gi\u00fap \u0111\u1ea3m b\u1ea3o r\u1eb1ng khung \u0111\u01b0\u1ee3c truy\u1ec1n \u0111i sau n\u00e0y c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c thi\u1ebft b\u1ecb nh\u1eadn x\u00e1c minh \u0111\u1ed9 to\u00e0n v\u1eb9n.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Vi\u1ec7c x\u00e1c minh \u1edf ph\u00eda ng\u01b0\u1eddi nh\u1eadn<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Khi khung \u0111\u1ebfn n\u01a1i, thi\u1ebft b\u1ecb nh\u1eadn t\u00ednh l\u1ea1i gi\u00e1 tr\u1ecb CRC-32 d\u1ef1a tr\u00ean n\u1ed9i dung khung \u0111\u00e3 nh\u1eadn.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Quy tr\u00ecnh x\u00e1c minh:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>Khung nh\u1eadn \u0111\u01b0\u1ee3c \u2192 T\u00ednh l\u1ea1i CRC \u2192 So s\u00e1nh v\u1edbi FCS<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Hai k\u1ebft qu\u1ea3 kh\u1ea3 thi:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"width: 317px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\" colwidth=\"317\"><p>K\u1ebft qu\u1ea3<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>H\u00e0nh \u0111\u1ed9ng<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"317\"><p>CRC kh\u1edbp v\u1edbi FCS<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Khung \u0111\u01b0\u1ee3c ch\u1ea5p nh\u1eadn<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"317\"><p>CRC kh\u00f4ng kh\u1edbp v\u1edbi FCS<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Khung b\u1ecb t\u1eeb ch\u1ed1i<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">C\u01a1 ch\u1ebf n\u00e0y cho ph\u00e9p c\u00e1c thi\u1ebft b\u1ecb Ethernet nhanh ch\u00f3ng ph\u00e1t hi\u1ec7n c\u00e1c g\u00f3i tin b\u1ecb l\u1ed7i do l\u1ed7i truy\u1ec1n, nhi\u1ec5u t\u00edn hi\u1ec7u ho\u1eb7c c\u00e1c v\u1ea5n \u0111\u1ec1 \u1edf t\u1ea7ng v\u1eadt l\u00fd.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >H\u00e0nh vi lo\u1ea1i b\u1ecf khung (Frame Discard Behavior)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">N\u1ebfu gi\u00e1 tr\u1ecb CRC \u0111\u01b0\u1ee3c t\u00ednh l\u1ea1i kh\u00f4ng kh\u1edbp v\u1edbi FCS \u0111\u00e3 nh\u1eadn, khung Ethernet s\u1ebd t\u1ef1 \u0111\u1ed9ng b\u1ecb lo\u1ea1i b\u1ecf.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c nguy\u00ean nh\u00e2n \u0111i\u1ec3n h\u00ecnh g\u00e2y l\u1ed7i khung bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>C\u00e1p Ethernet b\u1ecb h\u01b0 h\u1ecfng<\/p><\/li><li><p>\u0110\u1ea7u n\u1ed1i c\u00e1p quang b\u1ea9n<\/p><\/li><li><p><a target=\"_blank\" rel=\"\" href=\"https:\/\/www.rj45-modularjack.com\/news\/what-is-electromagnetic-interference-emi-and-why-it-matters-259389.html\">Nhi\u1ec5u \u0111i\u1ec7n t\u1eeb (EMI)<\/a><\/p><\/li><li><p>C\u00e1c m\u00f4-\u0111un quang SFP\/QSFP b\u1ecb l\u1ed7i<\/p><\/li><li><p>C\u00e1c v\u1ea5n \u0111\u1ec1 v\u1ec1 \u0111\u1ed9 to\u00e0n v\u1eb9n t\u00edn hi\u1ec7u tr\u00ean c\u00e1c li\u00ean k\u1ebft t\u1ed1c \u0111\u1ed9 cao<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ed d\u1ee5:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>D\u1eef li\u1ec7u g\u1ed1c \u2192 10101010<br> D\u1eef li\u1ec7u b\u1ecb l\u1ed7i \u2192 10101110<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Ngay c\u1ea3 m\u1ed9t thay \u0111\u1ed5i \u0111\u01a1n bit c\u0169ng c\u00f3 th\u1ec3 khi\u1ebfn vi\u1ec7c x\u00e1c minh CRC th\u1ea5t b\u1ea1i.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong c\u00e1c m\u1ea1ng doanh nghi\u1ec7p v\u00e0 trung t\u00e2m d\u1eef li\u1ec7u, vi\u1ec7c t\u0103ng d\u1ea7n c\u00e1c b\u1ed9 \u0111\u1ebfm CRC\/FCS tr\u00ean c\u00e1c switch th\u01b0\u1eddng cho th\u1ea5y c\u00e1c v\u1ea5n \u0111\u1ec1 truy\u1ec1n d\u1eabn \u1edf t\u1ea7ng th\u1ea5p h\u01a1n, \u0111\u1eb7c bi\u1ec7t tr\u00ean c\u00e1c li\u00ean k\u1ebft s\u1ee3i quang v\u00e0 k\u1ebft n\u1ed1i b\u1ed9 thu ph\u00e1t quang.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >\u2705 FCS so v\u1edbi CRC so v\u1edbi TCP Checksum: S\u1ef1 kh\u00e1c bi\u1ec7t l\u00e0 g\u00ec?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">CRC l\u00e0 thu\u1eadt to\u00e1n; FCS l\u00e0 tr\u01b0\u1eddng l\u01b0u tr\u1eef k\u1ebft qu\u1ea3 CRC b\u00ean trong khung Ethernet. TCP checksum th\u00ec kh\u00e1c: n\u00f3 ho\u1ea1t \u0111\u1ed9ng \u1edf t\u1ea7ng 4 v\u00e0 b\u1ea3o v\u1ec7 ph\u00e2n \u0111o\u1ea1n TCP, trong khi FCS b\u1ea3o v\u1ec7 khung t\u1ea7ng 2. V\u00ec nh\u1eefng ki\u1ec3m tra n\u00e0y x\u1ea3y ra \u1edf c\u00e1c t\u1ea7ng kh\u00e1c nhau, ch\u00fang gi\u1ea3i quy\u1ebft c\u00e1c v\u1ea5n \u0111\u1ec1 \u0111\u1ed9 tin c\u1eady kh\u00e1c nhau v\u00e0 kh\u00f4ng n\u00ean coi l\u00e0 ho\u00e1n \u0111\u1ed5i \u0111\u01b0\u1ee3c cho nhau.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"675\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/7e27c0cf2856496d8df3941e8d3d96e0.jpg\" alt=\"FCS vs. CRC vs. TCP Checksum: What Is the Difference?\" class=\"wp-image-7271\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/7e27c0cf2856496d8df3941e8d3d96e0.jpg 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/7e27c0cf2856496d8df3941e8d3d96e0-300x169.jpg 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/7e27c0cf2856496d8df3941e8d3d96e0-1024x576.jpg 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/7e27c0cf2856496d8df3941e8d3d96e0-768x432.jpg 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/7e27c0cf2856496d8df3941e8d3d96e0-18x10.jpg 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" >CRC l\u00e0 g\u00ec?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">CRC (Ki\u1ec3m tra d\u01b0 th\u1eeba v\u00f2ng \u2013 Cyclic Redundancy Check) l\u00e0 thu\u1eadt to\u00e1n to\u00e1n h\u1ecdc \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 ph\u00e1t hi\u1ec7n l\u1ed7i truy\u1ec1n.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong Ethernet: CRC-32<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">CRC ph\u00e2n t\u00edch n\u1ed9i dung nh\u1ecb ph\u00e2n c\u1ee7a khung Ethernet v\u00e0 t\u1ea1o ra m\u1ed9t gi\u00e1 tr\u1ecb x\u00e1c minh duy nh\u1ea5t.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Quy tr\u00ecnh c\u01a1 b\u1ea3n:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>D\u1eef li\u1ec7u khung \u2192 T\u00ednh to\u00e1n CRC \u2192 K\u1ebft qu\u1ea3 \u0111\u01b0\u1ee3c l\u01b0u trong FCS<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">B\u1ea3n th\u00e2n CRC kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t tr\u01b0\u1eddng hi\u1ec3n th\u1ecb trong khung. N\u00f3 ch\u1ec9 l\u00e0 ph\u01b0\u01a1ng ph\u00e1p t\u00ednh to\u00e1n \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 t\u1ea1o gi\u00e1 tr\u1ecb FCS.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >FCS l\u00e0 g\u00ec?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">FCS (Tr\u00ecnh t\u1ef1 ki\u1ec3m tra khung \u2013 Frame Check Sequence) l\u00e0 tr\u01b0\u1eddng th\u1ef1c t\u1ebf g\u1ed3m 4 byte n\u1eb1m \u1edf cu\u1ed1i khung Ethernet.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u1ea5u tr\u00fac \u0111\u01a1n gi\u1ea3n h\u00f3a:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>| Ti\u00eau \u0111\u1ec1 Ethernet | D\u1eef li\u1ec7u t\u1ea3i | FCS |<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">FCS ch\u1ee9a k\u1ebft qu\u1ea3 CRC do thi\u1ebft b\u1ecb g\u1eedi t\u00ednh to\u00e1n. Thi\u1ebft b\u1ecb nh\u1eadn s\u1ebd t\u00ednh l\u1ea1i CRC v\u00e0 so s\u00e1nh v\u1edbi gi\u00e1 tr\u1ecb FCS \u0111\u00e3 nh\u1eadn \u0111\u1ec3 x\u00e1c minh t\u00ednh to\u00e0n v\u1eb9n c\u1ee7a khung.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">N\u1ebfu c\u00e1c gi\u00e1 tr\u1ecb kh\u00f4ng kh\u1edbp:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>Khung b\u1ecb t\u1eeb ch\u1ed1i<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Qu\u00e1 tr\u00ecnh n\u00e0y gi\u00fap c\u00e1c thi\u1ebft b\u1ecb Ethernet nhanh ch\u00f3ng ph\u00e1t hi\u1ec7n c\u00e1c khung b\u1ecb l\u1ed7i do s\u1ef1 c\u1ed1 c\u00e1p, \u0111\u1ed9 \u1ed5n \u0111\u1ecbnh k\u00e9m c\u1ee7a m\u00f4-\u0111un quang, nhi\u1ec5u t\u00edn hi\u1ec7u ho\u1eb7c l\u1ed7i truy\u1ec1n d\u1eabn.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Ki\u1ec3m tra t\u1ed5ng TCP l\u00e0 g\u00ec?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Ki\u1ec3m tra t\u1ed5ng TCP l\u00e0 c\u01a1 ch\u1ebf ki\u1ec3m tra t\u00ednh to\u00e0n v\u1eb9n \u1edf t\u1ea7ng 4 \u0111\u01b0\u1ee3c giao th\u1ee9c TCP s\u1eed d\u1ee5ng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Kh\u00e1c v\u1edbi FCS\u2014ch\u1ec9 b\u1ea3o v\u1ec7 m\u1ed9t khung Ethernet duy nh\u1ea5t tr\u00ean li\u00ean k\u1ebft c\u1ee5c b\u1ed9\u2014ki\u1ec3m tra t\u1ed5ng TCP b\u1ea3o v\u1ec7 ph\u00e2n \u0111o\u1ea1n TCP tr\u00ean to\u00e0n b\u1ed9 \u0111\u01b0\u1eddng truy\u1ec1n t\u1eeb \u0111\u1ea7u \u0111\u1ebfn cu\u1ed1i.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ki\u1ec3m tra t\u1ed5ng TCP x\u00e1c minh:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Ti\u00eau \u0111\u1ec1 TCP<\/p><\/li><li><p>D\u1eef li\u1ec7u t\u1ea3i (payload)<\/p><\/li><li><p>Th\u00f4ng tin ti\u00eau \u0111\u1ec1 gi\u1ea3 (pseudo-header)<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Quy tr\u00ecnh \u0111\u01a1n gi\u1ea3n h\u00f3a:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>Ph\u00e2n \u0111o\u1ea1n TCP \u2192 T\u00ednh to\u00e1n ki\u1ec3m tra t\u1ed5ng \u2192 X\u00e1c minh t\u1ea1i m\u00e1y nh\u1eadn<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Ngay c\u1ea3 khi m\u1ed9t khung Ethernet v\u01b0\u1ee3t qua ki\u1ec3m tra FCS th\u00e0nh c\u00f4ng, vi\u1ec7c x\u00e1c minh ki\u1ec3m tra t\u1ed5ng TCP v\u1eabn c\u00f3 th\u1ec3 th\u1ea5t b\u1ea1i sau \u0111\u00f3 n\u1ebfu x\u1ea3y ra l\u1ed7i \u1edf n\u01a1i kh\u00e1c trong ng\u0103n x\u1ebfp m\u1ea1ng.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Nh\u1eefng kh\u00e1c bi\u1ec7t ch\u00ednh gi\u1eefa FCS, CRC v\u00e0 ki\u1ec3m tra t\u1ed5ng TCP<\/h3>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\"><p>M\u1ee5c<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>L\u1edbp OSI<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>B\u1ea3o v\u1ec7<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>V\u1ecb tr\u00ed t\u1ed3n t\u1ea1i<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>FCS<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>T\u1ea7ng 2<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Khung Ethernet<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Cu\u1ed1i khung Ethernet<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>CRC<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Kh\u00e1i ni\u1ec7m t\u1ea7ng 2<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>T\u00ednh to\u00e1n ph\u00e1t hi\u1ec7n l\u1ed7i<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>\u0110\u01b0\u1ee3c t\u00ednh to\u00e1n v\u00e0 l\u01b0u tr\u1eef trong FCS<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>Ki\u1ec3m tra t\u1ed5ng TCP<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>T\u1ea7ng 4<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Ph\u00e2n \u0111o\u1ea1n TCP<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Ti\u00eau \u0111\u1ec1 TCP<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" >\u2705 T\u1ea1i sao x\u1ea3y ra l\u1ed7i FCS tr\u00ean c\u00e1c switch, NIC, li\u00ean k\u1ebft s\u1ee3i quang v\u00e0 m\u00f4-\u0111un quang?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">L\u1ed7i FCS th\u01b0\u1eddng c\u00f3 ngh\u0129a l\u00e0 khung \u0111\u00e3 \u0111\u1ebfn b\u1ecb l\u1ed7i \u1edf \u0111\u00e2u \u0111\u00f3 d\u1ecdc theo \u0111\u01b0\u1eddng truy\u1ec1n. Trong c\u00e1c m\u1ea1ng th\u1ef1c t\u1ebf, nguy\u00ean nh\u00e2n g\u1ed1c r\u1ec5 th\u01b0\u1eddng li\u00ean quan \u0111\u1ebfn l\u1edbp v\u1eadt l\u00fd ho\u1eb7c ch\u1ea5t l\u01b0\u1ee3ng li\u00ean k\u1ebft: c\u00e1p h\u1ecfng, \u0111\u1ea7u n\u1ed1i s\u1ee3i quang b\u1ea9n, thi\u1ebft b\u1ecb quang kh\u00f4ng t\u01b0\u01a1ng th\u00edch, h\u00e0nh vi kho\u1ea3ng c\u00e1ch gi\u1eefa c\u00e1c khung (inter-frame gap) kh\u00f4ng \u0111\u00fang, ho\u1eb7c m\u00f4-\u0111un quang \u0111ang h\u1ecfng. T\u00e0i li\u1ec7u c\u1ee7a Cisco n\u00eau r\u1eb1ng l\u1ed7i CRC\/FCS c\u00f3 th\u1ec3 xu\u1ea5t hi\u1ec7n d\u01b0\u1edbi d\u1ea1ng l\u1ed7i \u0111\u1ea7u v\u00e0o ho\u1eb7c m\u1ea5t g\u00f3i tr\u00ean c\u00e1c thi\u1ebft b\u1ecb k\u1ebft n\u1ed1i v\u00e0 v\u1ea5n \u0111\u1ec1 th\u01b0\u1eddng n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng li\u00ean k\u1ebft ch\u1ee9 kh\u00f4ng ph\u1ea3i \u1edf c\u00e1c giao th\u1ee9c t\u1ea7ng tr\u00ean.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"675\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/40fb162a76634c70b44172d8cc18c143.jpg\" alt=\"Why Do FCS Errors Happen on Switches, NICs, Fiber Links, and Optical Modules?\" class=\"wp-image-7272\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/40fb162a76634c70b44172d8cc18c143.jpg 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/40fb162a76634c70b44172d8cc18c143-300x169.jpg 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/40fb162a76634c70b44172d8cc18c143-1024x576.jpg 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/40fb162a76634c70b44172d8cc18c143-768x432.jpg 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/40fb162a76634c70b44172d8cc18c143-18x10.jpg 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" >S\u1ef1 c\u1ed1 c\u00e1p \u0111\u1ed3ng<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1p Ethernet b\u1ecb h\u01b0 h\u1ea1i ho\u1eb7c ch\u1ea5t l\u01b0\u1ee3ng th\u1ea5p l\u00e0 m\u1ed9t trong nh\u1eefng nguy\u00ean nh\u00e2n ph\u1ed5 bi\u1ebfn nh\u1ea5t g\u00e2y ra l\u1ed7i FCS.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c v\u1ea5n \u0111\u1ec1 \u0111i\u1ec3n h\u00ecnh bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>C\u00e1c c\u1eb7p d\u00e2y c\u00e1p b\u1ecb \u0111\u1ee9t<\/p><\/li><li><p>L\u1edbp ch\u1eafn k\u00e9m<\/p><\/li><li><p>U\u1ed1n cong c\u00e1p qu\u00e1 m\u1ee9c<\/p><\/li><li><p>Lo\u1ea1i c\u00e1p kh\u00f4ng ph\u00f9 h\u1ee3p<\/p><\/li><li><p>K\u1ebft n\u1ed1i RJ45 l\u1ecfng l\u1ebbo<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ed d\u1ee5, m\u1ed9t c\u00e1p <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/knowledge-center\/cat5e-vs-cat6-vs-cat7-ethernet-cable\/\">Cat5e<\/a> \u0111ang ch\u1ea1y l\u01b0u l\u01b0\u1ee3ng 10GBASE-T c\u00f3 th\u1ec3 g\u00e2y ra l\u1ed7i bit l\u00e0m h\u1ecfng khung Ethernet trong qu\u00e1 tr\u00ecnh truy\u1ec1n.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Nhi\u1ec5m b\u1ea9n s\u1ee3i quang<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u1ea7u n\u1ed1i s\u1ee3i quang b\u1ea9n ho\u1eb7c b\u1ecb h\u01b0 h\u1ea1i l\u00e0 nguy\u00ean nh\u00e2n l\u1edbn g\u00e2y ra l\u1ed7i CRC\/FCS trong trung t\u00e2m d\u1eef li\u1ec7u.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ngay c\u1ea3 c\u00e1c h\u1ea1t b\u1ee5i vi m\u00f4 tr\u00ean \u0111\u1ea7u n\u1ed1i LC ho\u1eb7c MPO c\u0169ng c\u00f3 th\u1ec3 g\u00e2y ra:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Suy hao t\u00edn hi\u1ec7u quang<\/p><\/li><li><p>T\u1ed5n th\u1ea5t ph\u1ea3n x\u1ea1<\/p><\/li><li><p>T\u1ef7 l\u1ec7 l\u1ed7i bit (BER) t\u0103ng<\/p><\/li><li><p>H\u1ecfng g\u00f3i tin<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c ngu\u1ed3n nhi\u1ec5m b\u1ea9n ph\u1ed5 bi\u1ebfn bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>B\u1ee5i tr\u00ean \u0111\u1ea7u n\u1ed1i LC<\/p><\/li><li><p>\u0110\u1ea7u n\u1ed1i ferrule b\u1ecb tr\u1ea7y x\u01b0\u1edbc<\/p><\/li><li><p>Quy tr\u00ecnh l\u00e0m s\u1ea1ch kh\u00f4ng \u0111\u00fang c\u00e1ch<\/p><\/li><li><p>C\u00e1c d\u00e2y c\u00e1p MPO b\u1ecb nhi\u1ec5m b\u1ea9n<\/p><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" >T\u00ednh t\u01b0\u01a1ng th\u00edch c\u1ee7a module quang<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c module quang kh\u00f4ng t\u01b0\u01a1ng th\u00edch ho\u1eb7c kh\u00f4ng \u1ed5n \u0111\u1ecbnh th\u01b0\u1eddng g\u00e2y ra l\u1ed7i FCS v\u00e0 CRC trong m\u00f4i tr\u01b0\u1eddng doanh nghi\u1ec7p <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/knowledge-center\/what-is-a-network-switch\/\">routers<\/a> and <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/knowledge-center\/what-is-servers-components-types-functions\/\">, and fiber optic links through interchangeable transceiver modules. Unlike standard RJ45 Ethernet ports, SFP ports can support both fiber optic and copper Ethernet connections depending on the installed module.<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c module quang b\u1ecb \u1ea3nh h\u01b0\u1edfng c\u00f3 th\u1ec3 bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p><a target=\"_self\" href=\"https:\/\/www.l-p.com\/products\/478230.htm\">C\u00e1c m\u00f4-\u0111un SFP<\/a><\/p><\/li><li><p><a target=\"_self\" href=\"https:\/\/www.l-p.com\/products\/475415.htm\">b\u1ed9 chuy\u1ec3n \u0111\u1ed5i SFP+<\/a><\/p><\/li><li><p>Module quang QSFP\/QSFP28<\/p><\/li><li><p><a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/knowledge-center\/direct-attach-cables-dac-in-networking\/\">SFF-8472<\/a> and <a target=\"_self\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/knowledge-center\/aoc-explained-active-optical-cable-benefits-uses-advancements-guide\/\">AOC<\/a> C\u00e1p<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c nguy\u00ean nh\u00e2n ph\u1ed5 bi\u1ebfn bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>V\u1ea5n \u0111\u1ec1 t\u01b0\u01a1ng th\u00edch gi\u1eefa c\u00e1c nh\u00e0 cung c\u1ea5p<\/p><\/li><li><p>Kh\u00f4ng ch\u00ednh x\u00e1c <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/knowledge-center\/how-eeprom-powers-sfp-and-qsfp-optical-modules\/\">B\u1ed9 nh\u1edb EEPROM<\/a> Tham s\u1ed1<\/p><\/li><li><p>\u0110\u1ea7u ra laser kh\u00f4ng \u1ed5n \u0111\u1ecbnh<\/p><\/li><li><p>K\u00e9m <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/digital-signal-processor-functionality-in-optical-transceivers\/\">ti\u00ean ti\u1ebfn<\/a> \u0110i\u1ec1u ch\u1ec9nh<\/p><\/li><li><p>B\u1ed9 thu ph\u00e1t kh\u00f4ng \u0111\u01b0\u1ee3c ch\u1ee9ng nh\u1eadn<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c t\u00ecnh hu\u1ed1ng v\u00ed d\u1ee5:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"width: 337px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\" colwidth=\"337\"><p>V\u1ea5n \u0111\u1ec1 quang h\u1ecdc<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>\u1ea2nh h\u01b0\u1edfng \u0111i\u1ec3n h\u00ecnh<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"337\"><p>Module SFP+ kh\u00f4ng t\u01b0\u01a1ng th\u00edch<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>L\u1ed7i CRC ng\u1eaft qu\u00e3ng<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"337\"><p>Module quang QSFP28 h\u1ecfng<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>H\u1ecfng g\u00f3i tin<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"337\"><p>C\u00e1p DAC ch\u1ea5t l\u01b0\u1ee3ng k\u00e9m<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>M\u1ea5t t\u00ednh to\u00e0n v\u1eb9n t\u00edn hi\u1ec7u<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"337\"><p>Module quang qu\u00e1 n\u00f3ng<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>M\u1ea5t khung ng\u1eabu nhi\u00ean<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Trong nhi\u1ec1u tri\u1ec3n khai th\u1ef1c t\u1ebf, vi\u1ec7c thay th\u1ebf b\u1ed9 thu ph\u00e1t quang ngay l\u1eadp t\u1ee9c s\u1ebd gi\u1ea3i quy\u1ebft tri\u1ec7t \u0111\u1ec3 c\u00e1c v\u1ea5n \u0111\u1ec1 FCS dai d\u1eb3ng.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Nhi\u1ec7t \u0111\u1ed9 v\u00e0 l\u00e3o h\u00f3a<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c module quang v\u00e0 NIC c\u00f3 th\u1ec3 tr\u1edf n\u00ean kh\u00f4ng \u1ed5n \u0111\u1ecbnh khi nhi\u1ec7t \u0111\u1ed9 t\u0103ng l\u00ean ho\u1eb7c c\u00e1c linh ki\u1ec7n gi\u00e0 \u0111i theo th\u1eddi gian.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c v\u1ea5n \u0111\u1ec1 li\u00ean quan \u0111\u1ebfn l\u00e3o h\u00f3a ph\u1ed5 bi\u1ebfn bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Suy gi\u1ea3m c\u00f4ng su\u1ea5t laser<\/p><\/li><li><p>Tr\u00f4i nhi\u1ec7t<\/p><\/li><li><p>T\u1ef7 l\u1ec7 l\u1ed7i bit (BER) t\u0103ng<\/p><\/li><li><p>Kh\u00f4ng \u1ed5n \u0111\u1ecbnh <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/clock-and-data-recovery-in-modern-communication-systems\/\">Kh\u00f4i ph\u1ee5c \u0111\u1ed3ng h\u1ed3<\/a><\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">H\u00e0nh vi \u0111i\u1ec3n h\u00ecnh:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"width: 310px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\" colwidth=\"310\"><p>\u0110i\u1ec1u ki\u1ec7n<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>Tri\u1ec7u ch\u1ee9ng ph\u1ed5 bi\u1ebfn<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"310\"><p>Nhi\u1ec7t \u0111\u1ed9 switch cao<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>\u0110\u1ec9nh \u0111i\u1ec3m l\u1ed7i CRC<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"310\"><p>Module SFP l\u00e3o h\u00f3a<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>M\u1ea5t g\u00f3i d\u1eef li\u1ec7u ng\u1eaft qu\u00e3ng<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"310\"><p>Th\u1eddi gian ho\u1ea1t \u0111\u1ed9ng li\u00ean t\u1ee5c d\u00e0i<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>L\u1ed7i giao di\u1ec7n ng\u00e0y c\u00e0ng t\u0103ng<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"310\"><p>T\u1ea3i l\u01b0u l\u01b0\u1ee3ng cao<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>M\u1ea5t \u1ed5n \u0111\u1ecbnh li\u00ean k\u1ebft<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u00e2y l\u00e0 l\u00fd do v\u00ec sao <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/knowledge-center\/what-is-a-data-center\/\">trung t\u00e2m d\u1eef li\u1ec7u<\/a> C\u00e1c k\u1ef9 s\u01b0 v\u1eadn h\u00e0nh th\u01b0\u1eddng gi\u00e1m s\u00e1t c\u00e1c gi\u00e1 tr\u1ecb DOM\/DDM nh\u01b0:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>C\u00f4ng su\u1ea5t ph\u00e1t (Tx power)<\/p><\/li><li><p>C\u00f4ng su\u1ea5t thu (Rx power)<\/p><\/li><li><p>Nhi\u1ec7t \u0111\u1ed9 module<\/p><\/li><li><p>D\u00f2ng ph\u00e2n c\u1ef1c (Bias current)<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u1ec3 ph\u00e1t hi\u1ec7n s\u1edbm c\u00e1c module quang s\u1eafp h\u1ecfng tr\u01b0\u1edbc khi x\u1ea3y ra s\u1ef1 c\u1ed1 m\u1ea5t k\u1ebft n\u1ed1i ho\u00e0n to\u00e0n.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Kho\u1ea3ng c\u00e1ch gi\u1eefa c\u00e1c g\u00f3i tin (Interpacket Gap) v\u00e0 h\u00e0nh vi \u0111\u1ed3ng b\u1ed9 th\u1eddi gian<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">L\u1ed7i FCS c\u0169ng c\u00f3 th\u1ec3 x\u1ea3y ra khi h\u00e0nh vi \u0111\u1ed3ng b\u1ed9 th\u1eddi gian c\u1ee7a Ethernet tr\u1edf n\u00ean kh\u00f4ng \u1ed5n \u0111\u1ecbnh.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c k\u1ebft n\u1ed1i Ethernet hi\u1ec7n \u0111\u1ea1i ph\u1ee5 thu\u1ed9c v\u00e0o vi\u1ec7c \u0111\u1ed3ng b\u1ed9 th\u1eddi gian ch\u00ednh x\u00e1c gi\u1eefa c\u00e1c khung tin, bao g\u1ed3m c\u1ea3 vi\u1ec7c duy tr\u00ec kho\u1ea3ng c\u00e1ch gi\u1eefa c\u00e1c g\u00f3i tin (IPG) \u0111\u00fang quy chu\u1ea9n. N\u1ebfu c\u00e1c khung tin \u0111\u01b0\u1ee3c truy\u1ec1n qu\u00e1 g\u1ea7n nhau ho\u1eb7c \u0111\u1ed3ng b\u1ed9 th\u1eddi gian tr\u1edf n\u00ean kh\u00f4ng \u1ed5n \u0111\u1ecbnh, b\u1ed9 thu c\u00f3 th\u1ec3 x\u1eed l\u00fd sai ranh gi\u1edbi khung tin.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c nguy\u00ean nh\u00e2n ti\u1ec1m \u1ea9n bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Ph\u1ea7n m\u1ec1m\u56fa\u4ef6 NIC l\u1ed7i<\/p><\/li><li><p>S\u1ef1 b\u1ea5t \u1ed5n v\u1ec1 th\u1eddi gian \u1edf PHY<\/p><\/li><li><p>V\u1ea5n \u0111\u1ec1 v\u1ec1 ASIC switch<\/p><\/li><li><p>Nhi\u1ec5u th\u1eddi gian (jitter) tr\u00ean c\u00e1c k\u1ebft n\u1ed1i t\u1ed1c \u0111\u1ed9 cao<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Quy tr\u00ecnh \u0111\u01a1n gi\u1ea3n h\u00f3a:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>S\u1ef1 b\u1ea5t \u1ed5n v\u1ec1 th\u1eddi gian<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">M\u1eb7c d\u00f9 c\u00e1c s\u1ef1 c\u1ed1 FCS li\u00ean quan \u0111\u1ebfn th\u1eddi \u0111i\u1ec3m \u00edt ph\u1ed5 bi\u1ebfn h\u01a1n c\u00e1c s\u1ef1 c\u1ed1 c\u00e1p ho\u1eb7c quang h\u1ecdc, nh\u01b0ng ch\u00fang tr\u1edf n\u00ean quan tr\u1ecdng h\u01a1n trong c\u00e1c m\u00f4i tr\u01b0\u1eddng Ethernet t\u1ed1c \u0111\u1ed9 cao nh\u01b0:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Ethernet 100G<\/p><\/li><li><p>Ethernet 400G<\/p><\/li><li><p>M\u1ea1ng c\u1ee5m AI<\/p><\/li><li><p>Trung t\u00e2m d\u1eef li\u1ec7u quy m\u00f4 si\u00eau l\u1edbn<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Trong c\u00e1c m\u00f4i tr\u01b0\u1eddng n\u00e0y, ngay c\u1ea3 nh\u1eefng v\u1ea5n \u0111\u1ec1 nh\u1ecf nh\u1ea5t v\u1ec1 th\u1eddi \u0111i\u1ec3m ho\u1eb7c t\u00ednh to\u00e0n v\u1eb9n t\u00edn hi\u1ec7u c\u0169ng c\u00f3 th\u1ec3 l\u00e0m t\u0103ng nhanh b\u1ed9 \u0111\u1ebfm CRC\/FCS tr\u00ean c\u00e1c giao di\u1ec7n chuy\u1ec3n m\u1ea1ch.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >\u2705 C\u00e1ch kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 CRC\/FCS trong m\u1ea1ng th\u1ef1c t\u1ebf<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1ch hi\u1ec7u qu\u1ea3 nh\u1ea5t \u0111\u1ec3 kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 CRC\/FCS l\u00e0 c\u00e1ch ly t\u1eebng b\u01b0\u1edbc li\u00ean k\u1ebft v\u1eadt l\u00fd. Trong c\u00e1c m\u1ea1ng Ethernet th\u1ef1c t\u1ebf, c\u00e1c khung b\u1ecb l\u1ed7i th\u01b0\u1eddng do c\u00e1p, li\u00ean k\u1ebft s\u1ee3i quang, m\u00f4-\u0111un quang ho\u1eb7c c\u00e1c v\u1ea5n \u0111\u1ec1 v\u1ec1 ch\u1ea5t l\u01b0\u1ee3ng t\u00edn hi\u1ec7u ch\u1ee9 kh\u00f4ng ph\u1ea3i do c\u00e1c giao th\u1ee9c \u1edf t\u1ea7ng cao h\u01a1n. K\u1ef9 s\u01b0 m\u1ea1ng th\u01b0\u1eddng tu\u00e2n theo quy tr\u00ecnh \u0111\u01a1n gi\u1ea3n \u201cki\u1ec3m tra, thay th\u1ebf v\u00e0 so s\u00e1nh\u201d: ki\u1ec3m tra \u0111\u01b0\u1eddng d\u1eabn c\u00e1p ho\u1eb7c s\u1ee3i quang, l\u00e0m s\u1ea1ch c\u00e1c \u0111\u1ea7u n\u1ed1i, thay th\u1ebf m\u00f4-\u0111un quang SFP\/QSFP, so s\u00e1nh b\u1ed9 \u0111\u1ebfm giao di\u1ec7n \u1edf c\u1ea3 hai \u0111\u1ea7u v\u00e0 xem l\u1ea1i c\u00e1c gi\u00e1 tr\u1ecb ch\u1ea9n \u0111o\u00e1n DOM\/DDM \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1c li\u00ean k\u1ebft kh\u00f4ng \u1ed5n \u0111\u1ecbnh.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"675\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/9dfdfe7a7a83414a93769dc2f15ac38f.jpg\" alt=\"How to Troubleshoot CRC\/FCS Errors in Real Networks\" class=\"wp-image-7273\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/9dfdfe7a7a83414a93769dc2f15ac38f.jpg 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/9dfdfe7a7a83414a93769dc2f15ac38f-300x169.jpg 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/9dfdfe7a7a83414a93769dc2f15ac38f-1024x576.jpg 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/9dfdfe7a7a83414a93769dc2f15ac38f-768x432.jpg 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/9dfdfe7a7a83414a93769dc2f15ac38f-18x10.jpg 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c l\u1ed7i CRC\/FCS dai d\u1eb3ng kh\u00f4ng bao gi\u1edd \u0111\u01b0\u1ee3c b\u1ecf qua, \u0111\u1eb7c bi\u1ec7t tr\u00ean c\u00e1c li\u00ean k\u1ebft Ethernet 10G, 25G, 100G ho\u1eb7c 400G, n\u01a1i ngay c\u1ea3 vi\u1ec7c t\u0103ng nh\u1ecf nh\u1ea5t c\u1ee7a T\u1ef7 l\u1ec7 l\u1ed7i bit (BER) c\u0169ng c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn m\u1ea5t g\u00f3i v\u00e0 truy\u1ec1n l\u1ea1i.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >B\u01b0\u1edbc 1: Ki\u1ec3m tra b\u1ed9 \u0111\u1ebfm giao di\u1ec7n<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">B\u1eaft \u0111\u1ea7u b\u1eb1ng c\u00e1ch ki\u1ec3m tra th\u1ed1ng k\u00ea giao di\u1ec7n Ethernet tr\u00ean c\u00e1c thi\u1ebft b\u1ecb chuy\u1ec3n m\u1ea1ch, b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn ho\u1eb7c m\u00e1y ch\u1ee7.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c l\u1ec7nh th\u00f4ng d\u1ee5ng: <code>show interface<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">ho\u1eb7c tr\u00ean Linux: <code>ethtool -S eth0<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">T\u00ecm c\u00e1c b\u1ed9 \u0111\u1ebfm nh\u01b0:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>L\u1ed7i CRC<\/p><\/li><li><p>L\u1ed7i FCS<\/p><\/li><li><p>L\u1ed7i \u0111\u1ea7u v\u00e0o<\/p><\/li><li><p>L\u1ed7i c\u0103n ch\u1ec9nh<\/p><\/li><li><p>M\u1ea5t g\u00f3i tin<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Di\u1ec5n gi\u1ea3i \u0111i\u1ec3n h\u00ecnh:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"width: 314px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\" colwidth=\"314\"><p>H\u00e0nh vi b\u1ed9 \u0111\u1ebfm<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>Nguy\u00ean nh\u00e2n c\u00f3 th\u1ec3 x\u1ea3y ra<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"314\"><p>B\u1ed9 \u0111\u1ebfm CRC t\u0103ng ch\u1eadm<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>V\u1ea5n \u0111\u1ec1 t\u00edn hi\u1ec7u nh\u1ecf<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"314\"><p>B\u1ed9 \u0111\u1ebfm FCS t\u0103ng nhanh<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>S\u1ef1 m\u1ea5t \u1ed5n \u0111\u1ecbnh \u1edf t\u1ea7ng v\u1eadt l\u00fd<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"314\"><p>L\u1ed7i ch\u1ec9 xu\u1ea5t hi\u1ec7n \u1edf m\u1ed9t ph\u00eda<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>V\u1ea5n \u0111\u1ec1 truy\u1ec1n\/nh\u1eadn (Tx\/Rx)<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"314\"><p>L\u1ed7i xu\u1ea5t hi\u1ec7n \u1edf c\u1ea3 hai ph\u00eda<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>V\u1ea5n \u0111\u1ec1 c\u00e1p ho\u1eb7c s\u1ee3i quang<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Vi\u1ec7c theo d\u00f5i li\u1ec7u c\u00e1c b\u1ed9 \u0111\u1ebfm c\u00f3 ti\u1ebfp t\u1ee5c t\u0103ng hay kh\u00f4ng l\u00e0 r\u1ea5t quan tr\u1ecdng \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1c l\u1ed7i ng\u1eaft qu\u00e3ng.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >B\u01b0\u1edbc 2: Thay d\u00e2y nh\u1ea3y<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">D\u00e2y nh\u1ea3y l\u00e0 m\u1ed9t trong nh\u1eefng \u0111i\u1ec3m d\u1ec5 h\u1ecfng v\u00e0 ph\u1ed5 bi\u1ebfn nh\u1ea5t.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u1ed1i v\u1edbi li\u00ean k\u1ebft \u0111\u1ed3ng:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Thay c\u00e1p RJ45<\/p><\/li><li><p>X\u00e1c minh lo\u1ea1i c\u00e1p (<a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/knowledge-center\/cat5e-vs-cat6-vs-cat6a-for-copper-sfp\/\">Cat5e\/Cat6\/Cat6A<\/a>)<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u1ed1i v\u1edbi li\u00ean k\u1ebft s\u1ee3i quang:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Thay d\u00e2y nh\u1ea3y LC-LC<\/p><\/li><li><p>Ki\u1ec3m tra \u0111\u1ea7u n\u1ed1i MPO<\/p><\/li><li><p>L\u00e0m s\u1ea1ch m\u1eb7t cu\u1ed1i s\u1ee3i quang \u0111\u00fang c\u00e1ch<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c v\u1ea5n \u0111\u1ec1 s\u1ee3i quang ph\u1ed5 bi\u1ebfn bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Nhi\u1ec5m b\u1ee5i<\/p><\/li><li><p>S\u1ee3i quang b\u1ecb cong<\/p><\/li><li><p>H\u01b0 h\u1ecfng \u0111\u1ea7u n\u1ed1i<\/p><\/li><li><p>T\u1ed5n hao ch\u00e8n qu\u00e1 m\u1ee9c<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Trong nhi\u1ec1u tr\u01b0\u1eddng h\u1ee3p, vi\u1ec7c thay th\u1ebf ngay l\u1eadp t\u1ee9c d\u00e2y c\u00e1p n\u1ed1i c\u00f3 ch\u1ea5t l\u01b0\u1ee3ng th\u1ea5p ho\u1eb7c b\u1ecb h\u01b0 h\u1ecfng s\u1ebd lo\u1ea1i b\u1ecf ho\u00e0n to\u00e0n c\u00e1c l\u1ed7i CRC\/FCS.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >B\u01b0\u1edbc 3: Thay th\u1ebf m\u00f4-\u0111un quang<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">N\u1ebfu l\u1ed7i v\u1eabn ti\u1ebfp di\u1ec5n, h\u00e3y thay b\u1ed9 thu ph\u00e1t quang.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c thi\u1ebft b\u1ecb b\u1ecb \u1ea3nh h\u01b0\u1edfng c\u00f3 th\u1ec3 bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>C\u00e1c m\u00f4-\u0111un SFP<\/p><\/li><li><p><a target=\"_self\" href=\"https:\/\/www.l-p.com\/products\/475586.htm\">Quang h\u1ecdc SFP+<\/a><\/p><\/li><li><p>QSFP\/<a target=\"_self\" href=\"https:\/\/www.l-p.com\/products\/482749.htm\">b\u1ed9 thu ph\u00e1t QSFP28<\/a><\/p><\/li><li><p>C\u00e1p DAC\/AOC<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c tri\u1ec7u ch\u1ee9ng \u0111i\u1ec3n h\u00ecnh c\u1ee7a quang h\u1ecdc b\u1ecb l\u1ed7i:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"width: 306px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\" colwidth=\"306\"><p>Tri\u1ec7u ch\u1ee9ng<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>Nguy\u00ean nh\u00e2n c\u00f3 th\u1ec3 x\u1ea3y ra<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"306\"><p>L\u1ed7i CRC ng\u1eaft qu\u00e3ng<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Laser kh\u00f4ng \u1ed5n \u0111\u1ecbnh<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"306\"><p>Nh\u1ea5p nh\u00e1y li\u00ean k\u1ebft<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Quang h\u1ecdc qu\u00e1 nhi\u1ec7t<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"306\"><p>H\u1ecfng g\u00f3i tin<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>\u0110\u1ed9 b\u1ea5t \u1ed5n c\u1ee7a DSP<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"306\"><p>T\u1ef7 l\u1ec7 l\u1ed7i bit (BER) cao<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>B\u1ed9 thu ph\u00e1t \u0111\u00e3 l\u00e3o h\u00f3a<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Vi\u1ec7c thay th\u1ebf \u0111\u01a1n gi\u1ea3n m\u1ed9t b\u1ed9 quang th\u01b0\u1eddng l\u00e0 c\u00e1ch nhanh nh\u1ea5t \u0111\u1ec3 x\u00e1c nh\u1eadn li\u1ec7u b\u1ed9 thu ph\u00e1t c\u00f3 b\u1ecb l\u1ed7i hay kh\u00f4ng.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >B\u01b0\u1edbc 4: So s\u00e1nh c\u1ea3 hai \u0111\u1ea7u c\u1ee7a li\u00ean k\u1ebft<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Lu\u00f4n so s\u00e1nh th\u1ed1ng k\u00ea giao di\u1ec7n \u1edf c\u1ea3 hai ph\u00eda c\u1ee7a k\u1ebft n\u1ed1i Ethernet.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ed d\u1ee5:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>Switch A \u2194 Li\u00ean k\u1ebft s\u1ee3i quang \u2194 Switch B<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c c\u00e2u h\u1ecfi c\u1ea7n ki\u1ec3m tra:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>L\u1ed7i c\u00f3 \u0111ang gia t\u0103ng \u1edf c\u1ea3 hai \u0111\u1ea7u hay kh\u00f4ng?<\/p><\/li><li><p>Ch\u1ec9 m\u1ed9t ph\u00eda b\u00e1o l\u1ed7i CRC\/FCS?<\/p><\/li><li><p>Ph\u00eda truy\u1ec1n c\u00f3 \u1ed5n \u0111\u1ecbnh kh\u00f4ng?<\/p><\/li><li><p>Vi\u1ec7c m\u1ea5t g\u00f3i tin c\u00f3 \u0111\u1ed1i x\u1ee9ng kh\u00f4ng?<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Quy t\u1eafc chung:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\"><p>Quan s\u00e1t<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>Nguy\u00ean nh\u00e2n c\u00f3 kh\u1ea3 n\u0103ng x\u1ea3y ra<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>C\u1ea3 hai ph\u00eda \u0111\u1ec1u hi\u1ec3n th\u1ecb l\u1ed7i<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>V\u1ea5n \u0111\u1ec1 v\u1ec1 s\u1ee3i quang ho\u1eb7c c\u00e1p<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>Ch\u1ec9 m\u1ed9t ph\u00eda<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>V\u1ea5n \u0111\u1ec1 ph\u1ea7n c\u1ee9ng Tx\/Rx<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>Ch\u1ec9 xu\u1ea5t hi\u1ec7n d\u01b0\u1edbi t\u1ea3i cao<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>V\u1ea5n \u0111\u1ec1 v\u1ec1 \u0111\u1ed9 to\u00e0n v\u1eb9n t\u00edn hi\u1ec7u<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>L\u1ed7i xu\u1ea5t hi\u1ec7n sau khi thay quang h\u1ecdc<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>V\u1ea5n \u0111\u1ec1 v\u1ec1 switch\/b\u1ed9 NIC<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Vi\u1ec7c so s\u00e1nh n\u00e0y gi\u00fap x\u00e1c \u0111\u1ecbnh ch\u00ednh x\u00e1c v\u1ea5n \u0111\u1ec1 b\u1eaft ngu\u1ed3n t\u1eeb li\u00ean k\u1ebft, t\u1eeb m\u00f4-\u0111un quang hay t\u1eeb ph\u1ea7n c\u1ee9ng giao di\u1ec7n.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >B\u01b0\u1edbc 5: Xem l\u1ea1i ch\u1ea9n \u0111o\u00e1n DDM\/DOM<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c m\u00f4-\u0111un quang hi\u1ec7n \u0111\u1ea1i h\u1ed7 tr\u1ee3 <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/ddm-dom-in-optical-transceivers\/\">DOM\/DDM<\/a> gi\u00e1m s\u00e1t, cung c\u1ea5p ch\u1ea9n \u0111o\u00e1n quang h\u1ecdc theo th\u1eddi gian th\u1ef1c.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c d\u1ea5u hi\u1ec7u c\u1ea3nh b\u00e1o \u0111i\u1ec3n h\u00ecnh:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\"><p>Gi\u00e1 tr\u1ecb \u0111\u1ecdc DOM\/DDM<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>V\u1ea5n \u0111\u1ec1 c\u00f3 th\u1ec3 x\u1ea3y ra<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>C\u00f4ng su\u1ea5t Rx th\u1ea5p<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>S\u1ee3i quang b\u1ea9n ho\u1eb7c suy hao<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>Nhi\u1ec7t \u0111\u1ed9 cao<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>V\u1ea5n \u0111\u1ec1 l\u00e0m m\u00e1t<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>D\u00f2ng thi\u00ean \u00e1p cao<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Laser l\u00e3o h\u00f3a<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>C\u00f4ng su\u1ea5t dao \u0111\u1ed9ng<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Quang h\u1ecdc kh\u00f4ng \u1ed5n \u0111\u1ecbnh<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ed d\u1ee5, m\u1ed9t <a target=\"_self\" href=\"https:\/\/www.l-p.com\/products\/482487.htm\">m\u00f4-\u0111un QSFP28<\/a> c\u00f3 c\u00f4ng su\u1ea5t Rx kh\u00f4ng \u1ed5n \u0111\u1ecbnh c\u00f3 th\u1ec3 g\u00e2y ra c\u00e1c l\u1ed7i CRC\/FCS gi\u00e1n \u0111o\u1ea1n ngay c\u1ea3 khi li\u00ean k\u1ebft v\u1eabn hi\u1ec3n th\u1ecb tr\u1ea1ng th\u00e1i ho\u1ea1t \u0111\u1ed9ng b\u00ecnh th\u01b0\u1eddng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong c\u00e1c m\u00f4i tr\u01b0\u1eddng Ethernet t\u1ed1c \u0111\u1ed9 cao nh\u01b0 m\u1ea1ng 100G v\u00e0 400G, vi\u1ec7c gi\u00e1m s\u00e1t DOM\/DDM th\u01b0\u1eddng r\u1ea5t c\u1ea7n thi\u1ebft \u0111\u1ec3 ph\u00e1t hi\u1ec7n c\u00e1c v\u1ea5n \u0111\u1ec1 ti\u1ec1m \u1ea9n \u1edf l\u1edbp quang tr\u01b0\u1edbc khi li\u00ean k\u1ebft ho\u00e0n to\u00e0n th\u1ea5t b\u1ea1i.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >\u2705 T\u1ea1i sao Wireshark th\u01b0\u1eddng kh\u00f4ng hi\u1ec3n th\u1ecb FCS?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Nhi\u1ec1u k\u1ef9 s\u01b0 m\u1ea1ng k\u1ef3 v\u1ecdng s\u1ebd th\u1ea5y chu\u1ed7i ki\u1ec3m tra khung 4 byte (FCS) trong c\u00e1c b\u1ea3n ghi g\u00f3i tin, nh\u01b0ng trong h\u1ea7u h\u1ebft c\u00e1c tr\u01b0\u1eddng h\u1ee3p Wireshark kh\u00f4ng bao gi\u1edd nh\u1eadn \u0111\u01b0\u1ee3c tr\u01b0\u1eddng FCS t\u1eeb card giao di\u1ec7n m\u1ea1ng (NIC). C\u00e1c NIC hi\u1ec7n \u0111\u1ea1i v\u00e0 h\u1ec7 \u0111i\u1ec1u h\u00e0nh th\u01b0\u1eddng lo\u1ea1i b\u1ecf FCS tr\u01b0\u1edbc khi chuy\u1ec3n c\u00e1c g\u00f3i tin cho ph\u1ea7n m\u1ec1m b\u1eaft g\u00f3i. Do \u0111\u00f3, m\u1ed9t g\u00f3i tin c\u00f3 th\u1ec3 hi\u1ec3n th\u1ecb b\u00ecnh th\u01b0\u1eddng trong Wireshark ngay c\u1ea3 khi b\u1ed9 chuy\u1ec3n m\u1ea1ch, b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn ho\u1eb7c NIC \u0111ang b\u00e1o l\u1ed7i CRC\/FCS tr\u00ean giao di\u1ec7n v\u1eadt l\u00fd.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"675\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/f1916b7d68e340fabd50746e1a0bcd16.jpg\" alt=\"Why Does Wireshark Often Not Show FCS?\" class=\"wp-image-7274\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/f1916b7d68e340fabd50746e1a0bcd16.jpg 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/f1916b7d68e340fabd50746e1a0bcd16-300x169.jpg 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/f1916b7d68e340fabd50746e1a0bcd16-1024x576.jpg 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/f1916b7d68e340fabd50746e1a0bcd16-768x432.jpg 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/f1916b7d68e340fabd50746e1a0bcd16-18x10.jpg 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">H\u00e0nh vi n\u00e0y l\u00e0 m\u1ed9t trong nh\u1eefng nguy\u00ean nh\u00e2n g\u00e2y nh\u1ea7m l\u1eabn ph\u1ed5 bi\u1ebfn nh\u1ea5t khi kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 h\u1ecfng d\u1eef li\u1ec7u Ethernet.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >B\u1eaft g\u00f3i so v\u1edbi Khung tr\u00ean d\u00e2y c\u00e1p<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">G\u00f3i \u0111\u01b0\u1ee3c hi\u1ec3n th\u1ecb trong Wireshark kh\u00f4ng ph\u1ea3i l\u00fac n\u00e0o c\u0169ng gi\u1ed1ng h\u1ec7t khung Ethernet g\u1ed1c \u0111\u01b0\u1ee3c truy\u1ec1n tr\u00ean d\u00e2y c\u00e1p.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Truy\u1ec1n Ethernet th\u1ef1c t\u1ebf:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>| Ti\u00eau \u0111\u1ec1 Ethernet | D\u1eef li\u1ec7u t\u1ea3i | FCS |<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110i\u1ec1u m\u00e0 Wireshark th\u01b0\u1eddng nh\u1eadn \u0111\u01b0\u1ee3c:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>| Ti\u00eau \u0111\u1ec1 Ethernet | D\u1eef li\u1ec7u t\u1ea3i |<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ec card giao di\u1ec7n m\u1ea1ng (NIC) lo\u1ea1i b\u1ecf tr\u01b0\u1eddng FCS tr\u01b0\u1edbc khi chuy\u1ec3n g\u00f3i \u0111\u1ebfn h\u1ec7 \u0111i\u1ec1u h\u00e0nh, ph\u1ea7n m\u1ec1m b\u1eaft g\u00f3i c\u00f3 th\u1ec3 ch\u01b0a bao gi\u1edd nh\u00ecn th\u1ea5y tr\u01b0\u1eddng FCS g\u1ed1c d\u00e0i 4 byte.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u00e2y l\u00e0 l\u00fd do v\u00ec sao:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Wireshark c\u00f3 th\u1ec3 kh\u00f4ng hi\u1ec3n th\u1ecb tr\u01b0\u1eddng FCS<\/p><\/li><li><p>\u0110\u1ed9 d\u00e0i g\u00f3i tr\u00f4ng ng\u1eafn h\u01a1n<\/p><\/li><li><p>C\u00e1c l\u1ed7i CRC v\u1eabn t\u1ed3n t\u1ea1i tr\u00ean giao di\u1ec7n switch<\/p><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" >H\u00e0nh vi d\u1eddi t\u1ea3i c\u1ee7a NIC<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c NIC hi\u1ec7n \u0111\u1ea1i th\u1ef1c hi\u1ec7n nhi\u1ec1u thao t\u00e1c Ethernet tr\u1ef1c ti\u1ebfp trong ph\u1ea7n c\u1ee9ng nh\u1eb1m c\u1ea3i thi\u1ec7n hi\u1ec7u n\u0103ng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c ch\u1ee9c n\u0103ng d\u1eddi t\u1ea3i ph\u1ea7n c\u1ee9ng ph\u1ed5 bi\u1ebfn bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>T\u1ea1o FCS<\/p><\/li><li><p>X\u00e1c minh CRC<\/p><\/li><li><p>D\u1eddi t\u1ea3i ki\u1ec3m tra t\u1ed5ng ki\u1ec3m tra TCP<\/p><\/li><li><p>D\u1eddi t\u1ea3i ph\u00e2n \u0111o\u1ea1n<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Tr\u00ean h\u1ea7u h\u1ebft c\u00e1c h\u1ec7 th\u1ed1ng, NIC x\u00e1c minh CRC\/FCS tr\u01b0\u1edbc khi g\u00f3i \u0111\u1ebfn \u0111\u01b0\u1ee3c Wireshark.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Lu\u1ed3ng quy tr\u00ecnh:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>Khung Ethernet \u0111\u1ebfn<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">N\u1ebfu khung kh\u00f4ng v\u01b0\u1ee3t qua x\u00e1c minh CRC, NIC c\u00f3 th\u1ec3 lo\u1ea1i b\u1ecf ngay l\u1eadp t\u1ee9c khung \u0111\u00f3 thay v\u00ec chuy\u1ec3n n\u00f3 \u0111\u1ebfn h\u1ec7 \u0111i\u1ec1u h\u00e0nh.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Do \u0111\u00f3, c\u00e1c g\u00f3i b\u1ecb l\u1ed7i th\u01b0\u1eddng v\u00f4 h\u00ecnh trong c\u00e1c b\u1ea3n b\u1eaft g\u00f3i d\u00f9 b\u1ed9 \u0111\u1ebfm giao di\u1ec7n v\u1eabn ti\u1ebfp t\u1ee5c t\u0103ng.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >T\u1ea1i sao \u0111\u1ed9 d\u00e0i g\u00f3i tr\u00f4ng ng\u1eafn h\u01a1n k\u1ef3 v\u1ecdng<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">FCS Ethernet th\u00eam 4 byte v\u00e0o cu\u1ed1i khung.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1ec1 m\u1eb7t l\u00fd thuy\u1ebft:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>\u0110\u1ed9 d\u00e0i khung Ethernet<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Tuy nhi\u00ean, do FCS th\u01b0\u1eddng b\u1ecb NIC lo\u1ea1i b\u1ecf, Wireshark th\u01b0\u1eddng hi\u1ec3n th\u1ecb \u0111\u1ed9 d\u00e0i khung ng\u1eafn h\u01a1n 4 byte so v\u1edbi \u0111\u1ed9 d\u00e0i truy\u1ec1n th\u1ef1c t\u1ebf tr\u00ean d\u00e2y c\u00e1p.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ed d\u1ee5:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\"><p>Lo\u1ea1i khung<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>\u0110\u1ed9 d\u00e0i hi\u1ec3n th\u1ecb<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>Khung Ethernet th\u1ef1c t\u1ebf<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>1518 byte<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>Khung b\u1eaft \u0111\u01b0\u1ee3c m\u00e0 kh\u00f4ng c\u00f3 FCS<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>1514 byte<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">S\u1ef1 ch\u00eanh l\u1ec7ch n\u00e0y ho\u00e0n to\u00e0n b\u00ecnh th\u01b0\u1eddng trong h\u1ea7u h\u1ebft m\u00f4i tr\u01b0\u1eddng b\u1eaft g\u00f3i.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">M\u1ed9t s\u1ed1 b\u1ed9 th\u00edch nghi b\u1eaft g\u00f3i chuy\u00ean d\u1ee5ng v\u00e0 h\u1ec7 th\u1ed1ng gi\u00e1m s\u00e1t c\u00f3 th\u1ec3 gi\u1eef nguy\u00ean tr\u01b0\u1eddng FCS, nh\u01b0ng c\u00e1c NIC \u0111\u1ec3 b\u00e0n ti\u00eau chu\u1ea9n th\u01b0\u1eddng kh\u00f4ng xu\u1ea5t tr\u01b0\u1eddng n\u00e0y ra Wireshark theo m\u1eb7c \u0111\u1ecbnh.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Khi kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 li\u00ean quan \u0111\u1ebfn CRC\/FCS, k\u1ef9 s\u01b0 m\u1ea1ng do \u0111\u00f3 d\u1ef1a nhi\u1ec1u h\u01a1n v\u00e0o:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>B\u1ed9 \u0111\u1ebfm giao di\u1ec7n switch<\/p><\/li><li><p>Th\u1ed1ng k\u00ea NIC<\/p><\/li><li><p>Ch\u1ea9n \u0111o\u00e1n module quang<\/p><\/li><li><p>Gi\u00e1m s\u00e1t DOM\/DDM<\/p><\/li><li><p>Ki\u1ec3m tra l\u1edbp v\u1eadt l\u00fd<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">thay v\u00ec ch\u1ec9 d\u1ef1a v\u00e0o b\u1ea3n b\u1eaft g\u00f3i.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >\u2705 Li\u1ec7u m\u1ed9t s\u1ed1 l\u01b0\u1ee3ng nh\u1ecf l\u1ed7i CRC\/FCS c\u00f3 th\u1ec3 ch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c kh\u00f4ng?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Trong c\u00e1c m\u1ea1ng s\u1ea3n xu\u1ea5t, ngay c\u1ea3 m\u1ed9t s\u1ed1 l\u01b0\u1ee3ng l\u1ed7i CRC\/FCS nh\u1ecf nh\u01b0ng l\u1eb7p l\u1ea1i th\u01b0\u1eddng l\u00e0 d\u1ea5u hi\u1ec7u cho th\u1ea5y c\u00f3 v\u1ea5n \u0111\u1ec1, \u0111\u1eb7c bi\u1ec7t tr\u00ean c\u00e1c li\u00ean k\u1ebft t\u1ed1c \u0111\u1ed9 cao. C\u00e1c cu\u1ed9c th\u1ea3o lu\u1eadn tr\u00ean Reddit gi\u1eefa c\u00e1c k\u1ef9 s\u01b0 m\u1ea1ng li\u00ean t\u1ee5c m\u00f4 t\u1ea3 m\u1ee9c \u201cch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c\u201d l\u00e0 v\u1ec1 c\u01a1 b\u1ea3n b\u1eb1ng kh\u00f4ng trong c\u00e1c m\u00f4i tr\u01b0\u1eddng \u1ed5n \u0111\u1ecbnh, b\u1edfi v\u00ec ngay c\u1ea3 t\u1ef7 l\u1ec7 l\u1ed7i th\u1ea5p c\u0169ng c\u00f3 th\u1ec3 g\u00e2y ra vi\u1ec7c truy\u1ec1n l\u1ea1i, \u0111\u1ed9 tr\u1ec5 v\u00e0 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn \u1ee9ng d\u1ee5ng.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"675\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/0f53c3e969c04e8c9fa33cf0cb8b5fdc.jpg\" alt=\"Is a Small Number of CRC\/FCS Errors Acceptable?\" class=\"wp-image-7275\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/0f53c3e969c04e8c9fa33cf0cb8b5fdc.jpg 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/0f53c3e969c04e8c9fa33cf0cb8b5fdc-300x169.jpg 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/0f53c3e969c04e8c9fa33cf0cb8b5fdc-1024x576.jpg 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/0f53c3e969c04e8c9fa33cf0cb8b5fdc-768x432.jpg 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/0f53c3e969c04e8c9fa33cf0cb8b5fdc-18x10.jpg 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ec Ethernet t\u1ef1 \u0111\u1ed9ng lo\u1ea1i b\u1ecf c\u00e1c khung b\u1ecb l\u1ed7i, n\u00ean c\u00e1c l\u1ed7i FCS l\u1eb7p l\u1ea1i lu\u00f4n c\u1ea7n \u0111\u01b0\u1ee3c \u0111i\u1ec1u tra ch\u1ee9 kh\u00f4ng n\u00ean b\u1ecf qua.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Khi \u201ckh\u00f4ng\u201d l\u00e0 m\u1ee5c ti\u00eau<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Trong c\u00e1c m\u1ea1ng doanh nghi\u1ec7p v\u00e0 trung t\u00e2m d\u1eef li\u1ec7u, k\u1ef9 s\u01b0 m\u1ea1ng th\u01b0\u1eddng k\u1ef3 v\u1ecdng:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>L\u1ed7i CRC = 0<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u0111\u1eb7c bi\u1ec7t tr\u00ean:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Switch l\u00f5i<\/p><\/li><li><p>M\u1ea1ng l\u01b0u tr\u1eef<\/p><\/li><li><p>Ki\u1ebfn tr\u00fac spine-leaf<\/p><\/li><li><p>Li\u00ean k\u1ebft c\u1ee5m AI<\/p><\/li><li><p>M\u1ea1ng giao d\u1ecbch t\u1ea7n s\u1ed1 cao<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c li\u00ean k\u1ebft Ethernet \u1ed5n \u0111\u1ecbnh n\u00ean ho\u1ea1t \u0111\u1ed9ng m\u00e0 kh\u00f4ng x\u1ea3y ra t\u00ecnh tr\u1ea1ng h\u1ecfng khung li\u00ean t\u1ee5c.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">H\u00e0nh vi giao di\u1ec7n kh\u1ecfe m\u1ea1nh \u0111i\u1ec3n h\u00ecnh:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\"><p>Tr\u1ea1ng th\u00e1i giao di\u1ec7n<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>L\u1ed7i CRC\/FCS<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>Li\u00ean k\u1ebft \u1ed5n \u0111\u1ecbnh b\u00ecnh th\u01b0\u1eddng<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>0<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>S\u1ef1 ki\u1ec7n nh\u1ea5t th\u1eddi ng\u1eabu nhi\u00ean<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>R\u1ea5t th\u1ea5p<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>B\u1ed9 \u0111\u1ebfm t\u0103ng li\u00ean t\u1ee5c<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>C\u00f3 v\u1ea5n \u0111\u1ec1 t\u1ed3n t\u1ea1i<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">N\u1ebfu c\u00e1c b\u1ed9 \u0111\u1ebfm ti\u1ebfp t\u1ee5c t\u0103ng theo th\u1eddi gian, th\u00ec v\u1ea5n \u0111\u1ec1 th\u01b0\u1eddng kh\u00f4ng \u0111\u01b0\u1ee3c coi l\u00e0 b\u00ecnh th\u01b0\u1eddng.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Khi c\u00e1c l\u1ed7i ng\u1eaft qu\u00e3ng tr\u1edf th\u00e0nh v\u1ea5n \u0111\u1ec1<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">M\u1ed9t s\u1ed1 m\u00f4i tr\u01b0\u1eddng g\u1eb7p c\u00e1c \u0111\u1ee3t t\u0103ng \u0111\u1ed9t bi\u1ebfn CRC\/FCS ng\u1eaft qu\u00e3ng do:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Nhi\u1ec5u \u0111i\u1ec7n t\u1eeb (EMI)<\/p><\/li><li><p>\u0110\u1ea7u n\u1ed1i l\u1ecfng l\u1ebbo<\/p><\/li><li><p>Thi\u1ebft b\u1ecb quang gi\u00e0 c\u1ed7i<\/p><\/li><li><p>Bi\u1ebfn \u0111\u1ed9ng nhi\u1ec7t \u0111\u1ed9<\/p><\/li><li><p>Ch\u1ea5t l\u01b0\u1ee3ng c\u00e1p k\u00e9m<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Ngay c\u1ea3 khi t\u1ef7 l\u1ec7 l\u1ed7i tr\u00f4ng c\u00f3 v\u1ebb th\u1ea5p, s\u1ef1 h\u1ecfng h\u00f3c ng\u1eaft qu\u00e3ng v\u1eabn c\u00f3 th\u1ec3 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Vi\u1ec7c truy\u1ec1n l\u1ea1i TCP<\/p><\/li><li><p>L\u01b0u l\u01b0\u1ee3ng l\u01b0u tr\u1eef<\/p><\/li><li><p>Ch\u1ea5t l\u01b0\u1ee3ng tho\u1ea1i\/video<\/p><\/li><li><p>\u0110\u1ed3ng b\u1ed9 h\u00f3a c\u01a1 s\u1edf d\u1eef li\u1ec7u<\/p><\/li><li><p>C\u00f4ng vi\u1ec7c AI th\u1eddi gian th\u1ef1c<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">H\u00e0nh vi v\u00ed d\u1ee5:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>T\u1ef7 l\u1ec7 l\u1ed7i bit (BER) th\u1ea5p<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Trong nhi\u1ec1u m\u00f4i tr\u01b0\u1eddng s\u1ea3n xu\u1ea5t, c\u00e1c l\u1ed7i ng\u1eaft qu\u00e3ng tr\u1edf n\u00ean r\u00f5 r\u1ec7t h\u01a1n trong c\u00e1c giai \u0111o\u1ea1n:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Th\u1eddi \u0111i\u1ec3m l\u01b0u l\u01b0\u1ee3ng \u0111\u1ea1t \u0111\u1ec9nh<\/p><\/li><li><p>Nhi\u1ec7t \u0111\u1ed9 cao<\/p><\/li><li><p>Truy\u1ec1n t\u1ec7p l\u1edbn<\/p><\/li><li><p>L\u01b0u l\u01b0\u1ee3ng east-west ng\u1eaft qu\u00e3ng<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u00e2y l\u00e0 l\u00fd do v\u00ec sao c\u00e1c l\u1ed7i CRC\/FCS l\u1eb7p l\u1ea1i th\u01b0\u1eddng \u0111\u01b0\u1ee3c xem nh\u01b0 d\u1ea5u hi\u1ec7u c\u1ea3nh b\u00e1o s\u1edbm tr\u01b0\u1edbc khi x\u1ea3y ra s\u1ef1 c\u1ed1 li\u00ean k\u1ebft nghi\u00eam tr\u1ecdng h\u01a1n.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >T\u1ea1i sao c\u00e1c li\u00ean k\u1ebft t\u1ed1c \u0111\u1ed9 cao \u00edt khoan dung h\u01a1n<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Khi t\u1ed1c \u0111\u1ed9 Ethernet t\u0103ng l\u00ean, \u0111\u1ed9 to\u00e0n v\u1eb9n t\u00edn hi\u1ec7u tr\u1edf n\u00ean nh\u1ea1y c\u1ea3m h\u01a1n r\u1ea5t nhi\u1ec1u.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c li\u00ean k\u1ebft t\u1ed1c \u0111\u1ed9 cao h\u01a1n nh\u01b0:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Ethernet 25G<\/p><\/li><li><p>Ethernet 100G<\/p><\/li><li><p>Ethernet 400G<\/p><\/li><li><p>Ethernet 800G<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">ho\u1ea1t \u0111\u1ed9ng v\u1edbi:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>T\u1ed1c \u0111\u1ed9 t\u00edn hi\u1ec7u cao h\u01a1n<\/p><\/li><li><p>\u0110\u1ed9 dung sai th\u1eddi gian ch\u1eb7t ch\u1ebd h\u01a1n<\/p><\/li><li><p>\u0110\u1ed9 nh\u1ea1y cao h\u01a1n v\u1edbi nhi\u1ec5u v\u00e0 \u0111\u1ed9 m\u00e9o th\u1eddi gian (jitter)<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Xu h\u01b0\u1edbng chung:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"width: 282px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\" colwidth=\"282\"><p>T\u1ed1c \u0111\u1ed9 Ethernet<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>\u0110\u1ed9 nh\u1ea1y l\u1ed7i<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"282\"><p>1G<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Lower<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"282\"><p>Kh\u00f4ng b\u1ecb \u1ea3nh h\u01b0\u1edfng b\u1edfi nhi\u1ec5u \u0111i\u1ec7n t\u1eeb, \u0111\u1ea3m b\u1ea3o hi\u1ec7u su\u1ea5t \u1ed5n \u0111\u1ecbnh trong m\u00f4i tr\u01b0\u1eddng kh\u1eafc nghi\u1ec7t.<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Trung b\u00ecnh<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"282\"><p>25G<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Cao h\u01a1n<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"282\"><p>100G<br><\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>R\u1ea5t cao<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"282\"><p>400G+<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>C\u1ef1c k\u1ef3 nh\u1ea1y c\u1ea3m<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ec v\u1eady, c\u00e1c v\u1ea5n \u0111\u1ec1 c\u00f3 th\u1ec3 kh\u00f4ng \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn li\u00ean k\u1ebft 1G l\u1ea1i d\u1ec5 d\u00e0ng g\u00e2y ra l\u1ed7i CRC\/FCS tr\u00ean c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng Ethernet t\u1ed1c \u0111\u1ed9 cao hi\u1ec7n \u0111\u1ea1i.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c nguy\u00ean nh\u00e2n ph\u1ed5 bi\u1ebfn \u1edf t\u1ed1c \u0111\u1ed9 cao bao g\u1ed3m:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>\u0110\u1ea7u n\u1ed1i MPO b\u1ea9n<\/p><\/li><li><p>Bi\u00ean \u0111\u1ed9 h\u1ea1n ch\u1ebf <a target=\"_self\" href=\"https:\/\/www.l-p.com\/products\/488423.htm\">Module quang QSFP28 k\u00e9m ch\u1ea5t l\u01b0\u1ee3ng<\/a><\/p><\/li><li><p>Ch\u1ea5t l\u01b0\u1ee3ng c\u00e1p DAC k\u00e9m<\/p><\/li><li><p>V\u1ea5n \u0111\u1ec1 \u0111\u1ed9 to\u00e0n v\u1eb9n t\u00edn hi\u1ec7u tr\u00ean b\u1ea3ng m\u1ea1ch in (PCB)<\/p><\/li><li><p>B\u1ea5t \u1ed5n nhi\u1ec7t<\/p><\/li><li><p>M\u1ea5t c\u00e2n b\u1eb1ng c\u00f4ng su\u1ea5t quang<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Trong c\u00e1c trung t\u00e2m d\u1eef li\u1ec7u hi\u1ec7n \u0111\u1ea1i, c\u00e1c l\u1ed7i CRC\/FCS l\u1eb7p l\u1ea1i tr\u00ean c\u00e1c c\u1ed5ng t\u1ed1c \u0111\u1ed9 cao th\u01b0\u1eddng \u0111\u01b0\u1ee3c coi l\u00e0 ch\u1ec9 b\u00e1o v\u1ec1 ch\u1ea5t l\u01b0\u1ee3ng li\u00ean k\u1ebft suy gi\u1ea3m, \u0111\u00f2i h\u1ecfi \u0111i\u1ec1u tra ngay l\u1eadp t\u1ee9c.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >\u2705 K\u1ebft lu\u1eadn: C\u00e1c l\u1ed7i FCS n\u00f3i l\u00ean \u0111i\u1ec1u g\u00ec v\u1ec1 \u0111\u1ed9 tin c\u1eady m\u1ea1ng<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">D\u00e3y Ki\u1ec3m tra Khung (FCS) l\u00e0 m\u1ed9t trong nh\u1eefng c\u01a1 ch\u1ebf ki\u1ec3m tra t\u00ednh to\u00e0n v\u1eb9n quan tr\u1ecdng nh\u1ea5t trong m\u1ea1ng Ethernet. B\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng x\u00e1c minh CRC-32 \u1edf L\u1edbp 2, c\u00e1c thi\u1ebft b\u1ecb Ethernet c\u00f3 th\u1ec3 nhanh ch\u00f3ng ph\u00e1t hi\u1ec7n c\u00e1c khung b\u1ecb l\u1ed7i tr\u01b0\u1edbc khi d\u1eef li\u1ec7u kh\u00f4ng h\u1ee3p l\u1ec7 \u0111\u1ebfn c\u00e1c \u1ee9ng d\u1ee5ng ho\u1eb7c d\u1ecbch v\u1ee5 \u1edf c\u00e1c l\u1edbp cao h\u01a1n. Khi x\u00e1c minh FCS th\u1ea5t b\u1ea1i, v\u1ea5n \u0111\u1ec1 th\u01b0\u1eddng li\u00ean quan \u0111\u1ebfn \u0111\u01b0\u1eddng truy\u1ec1n v\u1eadt l\u00fd ch\u1ee9 kh\u00f4ng ph\u1ea3i c\u00e1c giao th\u1ee9c \u1edf l\u1edbp TCP hay l\u1edbp \u1ee9ng d\u1ee5ng.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"675\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1fe7cb7bfbf243bab5a0e65faafcf36e.jpg\" alt=\"What FCS Errors Mean for Network Reliability\" class=\"wp-image-7276\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1fe7cb7bfbf243bab5a0e65faafcf36e.jpg 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1fe7cb7bfbf243bab5a0e65faafcf36e-300x169.jpg 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1fe7cb7bfbf243bab5a0e65faafcf36e-1024x576.jpg 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1fe7cb7bfbf243bab5a0e65faafcf36e-768x432.jpg 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1fe7cb7bfbf243bab5a0e65faafcf36e-18x10.jpg 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Trong c\u00e1c m\u00f4i tr\u01b0\u1eddng doanh nghi\u1ec7p v\u00e0 trung t\u00e2m d\u1eef li\u1ec7u th\u1ef1c t\u1ebf, c\u00e1c l\u1ed7i CRC\/FCS l\u1eb7p \u0111i l\u1eb7p l\u1ea1i tuy\u1ec7t \u0111\u1ed1i kh\u00f4ng \u0111\u01b0\u1ee3c b\u1ecf qua. Ngay c\u1ea3 m\u1ed9t s\u1ed1 l\u01b0\u1ee3ng l\u1ed7i nh\u1ecf nh\u01b0ng li\u00ean t\u1ee5c t\u0103ng l\u00ean c\u0169ng c\u00f3 th\u1ec3 cho th\u1ea5y c\u00e1c v\u1ea5n \u0111\u1ec1 s\u00e2u xa h\u01a1n nh\u01b0 c\u00e1p Ethernet b\u1ecb h\u01b0 h\u1ecfng, \u0111\u1ea7u n\u1ed1i s\u1ee3i quang b\u1ea9n, \u0111\u1ed9 to\u00e0n v\u1eb9n t\u00edn hi\u1ec7u kh\u00f4ng \u1ed5n \u0111\u1ecbnh, card m\u1ea1ng (NIC) g\u1eb7p s\u1ef1 c\u1ed1 ho\u1eb7c c\u00e1c m\u00f4-\u0111un quang h\u1ecdc SFP, SFP+, QSFP v\u00e0 QSFP28 b\u1ecb l\u1ed7i.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Khi m\u1ea1ng Ethernet ti\u1ebfp t\u1ee5c ph\u00e1t tri\u1ec3n h\u01b0\u1edbng t\u1edbi c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng hi\u1ec7u n\u0103ng cao 100G, 400G v\u00e0 do tr\u00ed tu\u1ec7 nh\u00e2n t\u1ea1o \u0111i\u1ec1u khi\u1ec3n, vi\u1ec7c duy tr\u00ec T\u1ef7 l\u1ec7 l\u1ed7i bit (BER) th\u1ea5p v\u00e0 truy\u1ec1n d\u1eabn quang \u1ed5n \u0111\u1ecbnh ng\u00e0y c\u00e0ng tr\u1edf n\u00ean quan tr\u1ecdng. C\u00e1c k\u1ebft n\u1ed1i t\u1ed1c \u0111\u1ed9 cao hi\u1ec7n \u0111\u1ea1i ho\u1ea1t \u0111\u1ed9ng v\u1edbi bi\u00ean \u0111\u1ed9 t\u00edn hi\u1ec7u r\u1ea5t ch\u1eb7t ch\u1ebd, ngh\u0129a l\u00e0 ngay c\u1ea3 nh\u1eefng sai l\u1ec7ch nh\u1ecf \u1edf l\u1edbp v\u1eadt l\u00fd c\u0169ng c\u00f3 th\u1ec3 nhanh ch\u00f3ng d\u1eabn \u0111\u1ebfn l\u1ed7i g\u00f3i tin, y\u00eau c\u1ea7u truy\u1ec1n l\u1ea1i, t\u0103ng \u0111\u1ed9 tr\u1ec5 v\u00e0 m\u1ea5t \u1ed5n \u0111\u1ecbnh \u1ee9ng d\u1ee5ng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">B\u00e0i h\u1ecdc th\u1ef1c ti\u1ec5n nh\u1ea5t l\u00e0 \u0111\u01a1n gi\u1ea3n:<\/p>\n\n\n\n<pre class=\"wp-block-code\">\n<code>C\u00e1c l\u1ed7i CRC\/FCS l\u1eb7p l\u1ea1i g\u1ea7n nh\u01b0 lu\u00f4n lu\u00f4n cho th\u1ea5y \u0111\u01b0\u1eddng truy\u1ec1n v\u1eadt l\u00fd c\u1ea7n \u0111\u01b0\u1ee3c \u0111i\u1ec1u tra.<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Trong h\u1ea7u h\u1ebft c\u00e1c tr\u01b0\u1eddng h\u1ee3p, quy tr\u00ecnh kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 nhanh nh\u1ea5t l\u00e0:<\/p>\n\n\n\n<ol class=\"wp-block-list\" >\n<li><p>Ki\u1ec3m tra b\u1ed9 \u0111\u1ebfm tr\u00ean giao di\u1ec7n<\/p><\/li><li><p>Thay c\u00e1p ho\u1eb7c d\u00e2y nh\u1ea3y s\u1ee3i quang<\/p><\/li><li><p>L\u00e0m s\u1ea1ch v\u00e0 ki\u1ec3m tra \u0111\u1ea7u n\u1ed1i<\/p><\/li><li><p>Ho\u00e1n \u0111\u1ed5i <a target=\"_self\" href=\"https:\/\/www.l-p.com\/store-25432-optics-transceivers-sfp-modules.htm\">b\u1ed9 thu ph\u00e1t quang<\/a><\/p><\/li><li><p>Xem l\u1ea1i ch\u1ea9n \u0111o\u00e1n DOM\/DDM<\/p><\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u1ed1i v\u1edbi k\u1ef9 s\u01b0 m\u1ea1ng, ng\u01b0\u1eddi v\u1eadn h\u00e0nh trung t\u00e2m d\u1eef li\u1ec7u v\u00e0 qu\u1ea3n tr\u1ecb vi\u00ean CNTT, b\u1ed9 \u0111\u1ebfm FCS v\u1eabn l\u00e0 m\u1ed9t trong nh\u1eefng ch\u1ec9 b\u00e1o s\u1edbm nh\u1ea5t v\u00e0 gi\u00e1 tr\u1ecb nh\u1ea5t v\u1ec1 t\u00ecnh tr\u1ea1ng s\u1ee9c kh\u1ecfe c\u1ee7a \u0111\u01b0\u1eddng truy\u1ec1n Ethernet.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >T\u00e0i nguy\u00ean \u0111\u1ec1 xu\u1ea5t<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p><a target=\"_self\" href=\"https:\/\/www.l-p.com\/\">C\u1eeda h\u00e0ng Ch\u00ednh th\u1ee9c LINK-PP<\/a> M\u00f4-\u0111un SFP<\/p><\/li><li><p><a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/knowledge-center\/how-to-test-sfp-compatibility\/\">H\u01b0\u1edbng d\u1eabn t\u01b0\u01a1ng th\u00edch b\u1ed9 thu ph\u00e1t quang<\/a><\/p><\/li><li><p>Th\u1ef1c h\u00e0nh t\u1ed1t nh\u1ea5t v\u1ec1 l\u00e0m s\u1ea1ch v\u00e0 ki\u1ec3m tra s\u1ee3i quang<\/p><\/li><li><p>Danh s\u00e1ch ki\u1ec3m tra kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 CRC\/FCS Ethernet<\/p><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" >Ti\u1ec3u s\u1eed t\u00e1c gi\u1ea3<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u01b0\u1ee3c vi\u1ebft b\u1edfi chuy\u00ean gia n\u1ed9i dung v\u1ec1 c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng m\u1ea1ng, c\u00f3 kinh nghi\u1ec7m th\u1ef1c t\u1ebf trong vi\u1ec7c kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 Ethernet, t\u01b0\u01a1ng th\u00edch b\u1ed9 thu ph\u00e1t quang v\u00e0 m\u1ea1ng s\u1ee3i quang.<\/p>","protected":false},"excerpt":{"rendered":"<p>\u00dd ngh\u0129a c\u1ee7a chu\u1ed7i ki\u1ec3m tra khung (FCS), c\u00e1ch CRC-32 ph\u00e1t hi\u1ec7n c\u00e1c khung Ethernet b\u1ecb l\u1ed7i v\u00e0 l\u00fd do l\u1ed7i FCS th\u01b0\u1eddng li\u00ean quan \u0111\u1ebfn s\u1ef1 c\u1ed1 c\u00e1p, v\u1ea5n \u0111\u1ec1 s\u1ee3i quang ho\u1eb7c b\u1ed9 thu ph\u00e1t quang.<\/p>","protected":false},"author":1,"featured_media":7277,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[27],"tags":[26],"class_list":["post-7278","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-glossary","tag-optics-transceivers"],"blocksy_meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/posts\/7278","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/comments?post=7278"}],"version-history":[{"count":6,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/posts\/7278\/revisions"}],"predecessor-version":[{"id":10688,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/posts\/7278\/revisions\/10688"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/media\/7277"}],"wp:attachment":[{"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/media?parent=7278"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/categories?post=7278"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/tags?post=7278"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}