{"id":480,"date":"2024-02-28T17:51:01","date_gmt":"2024-02-28T09:51:01","guid":{"rendered":"https:\/\/idc.birk.cn\/?p=480"},"modified":"2024-02-28T20:41:21","modified_gmt":"2024-02-28T12:41:21","slug":"mtu%e6%8e%a2%e6%b5%8b%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/idc.birk.cn\/?p=480","title":{"rendered":"MTU\u63a2\u6d4b\u65b9\u6cd5"},"content":{"rendered":"

\u4ec0\u4e48\u662fMTU\uff1f<\/h3>\n

\u7f51\u7edc\u5c42\u53d1\u9001\u6570\u636e\u5305\u662f\u6709\u6700\u5927\u957f\u5ea6\u7684\uff0c\u7f51\u7edc\u5c42\u4ece\u4f20\u8f93\u5c42\u63a5\u6536\u5230\u8981\u53d1\u9001\u7684\u6570\u636e\u5305\u65f6\uff0c\u5b83\u8981\u5224\u65ad\u5411\u672c\u5730\u54ea\u4e2a\u63a5\u53e3\u53d1\u9001\u6570\u636e\uff0c\u5e76\u67e5\u8be2\u8be5\u63a5\u53e3\u83b7\u5f97\u5176\u6700\u5927\u4f20\u8f93\u5355\u5143MTU\uff08MaximumTransmissionUnit\uff09\uff0c\u7f51\u7edc\u5c42\u628aMTU\u503c\u4e0e\u8981\u53d1\u9001\u7684IP\u6570\u636e\u5305\u957f\u5ea6\u8fdb\u884c\u6bd4\u8f83\uff0c\u5982\u679cIP\u6570\u636e\u5305\u7684\u957f\u5ea6\u6bd4MTU\u503c\u5927\uff0c\u90a3\u4e48IP\u6570\u636e\u5305\u5c31\u9700\u8981\u8fdb\u884c\u5206\u7247\uff0c\u5206\u7247\u540e\u7684\u6570\u636e\u5305\u957f\u5ea6\u5c0f\u4e8e\u7b49\u4e8eMTU(\u5305\u62ecIP\u5c42\u5934\u90e8\uff0c\u5927\u5c0f\u5355\u4f4d\uff1abyte)<\/p>\n

MTU\u4e0d\u4e00\u81f4\u7ecf\u5e38\u5f15\u8d77\u7684\u6545\u969c\u73b0\u8c61\uff1a<\/h3>\n

1\u3001\u5728\u7f51\u7edc\u4e2d\uff0c\u7531\u4e8e\u4e0d\u540c\u5382\u5546\uff0c\u751a\u81f3\u540c\u4e00\u5382\u5546\u4e0d\u540c\u578b\u53f7\u7684\u8bbe\u5907\uff0c\u5bf9MTU\u7684\u5b9a\u4e49\u548cMTU\u5206\u7247\u673a\u5236\u4e0d\u5c3d\u76f8\u540c\uff0c\u5e38\u51fa\u73b0MTU\u5f15\u8d77\u7684\u7f51\u7edc\u95ee\u9898\uff0c\u5e38\u8868\u73b0\u4e3a\u6e38\u620f\u5361\u3001\u90e8\u5206\u7f51\u7ad9\u6216\u94fe\u63a5\u6253\u4e0d\u5f00\uff0cEmail\u65e0\u6cd5\u53d1\u9001\u9644\u4ef6\uff0c\u90e8\u5206\u7f51\u9875\u6216\u5bf9\u8bdd\u6846\u65e0\u6cd5\u6253\u5f00\u7b49\u3002\u9047\u5230\u6b64\u7c7b\u95ee\u9898\u65f6\uff0c\u5efa\u8bae\u5148\u68c0\u67e5\u662f\u5426\u63a5\u53e3MTU\u4e0d\u5339\u914d\u5bfc\u81f4\u3002
\n\u6b64\u5916\uff0cOSPF\u3001IS-IS\u3001L2VPN\u3001VPLS\u7b49\u534f\u8bae\u90bb\u5c45\u5173\u7cfb\u65e0\u6cd5\u5efa\u7acb\uff0c\u4e5f\u53ef\u80fd\u662f\u94fe\u8def\u4e24\u7aefMTU\u503c\u4e0d\u4e00\u81f4\u5bfc\u81f4\u3002<\/p>\n

2\u3001\u901f\u7387\u65e0\u6cd5\u8fbe\u5230\u9884\u671f<\/p>\n

\u89e3\u51b3\u65b9\u6cd5\uff1a<\/h3>\n

\u8c03\u6574\u673a\u5668MTU<\/p>\n

\u5982\u4f55\u6d4b\u8bd5MTU\uff1f<\/h3>\n

Linux\u4e3b\u673a\u4e2d: \u6267\u884cping x.x.x.x -s 1422 -M do\u00a0 \/\/x.x.x.x\u662f\u76ee\u6807\u5730\u5740
\n-s\u6307\u660eicmp\u62a5\u6587\u7684\u6570\u636e\u90e8\u5206\u5927\u5c0f(\u4e0d\u5305\u542bicmp 8\u5b57\u8282\u5934\u90e8)
\n-M do \u8868\u793a\u4e0d\u5141\u8bb8\u5206\u7247\u3002\u591a\u8bd5\u51e0\u6b21\uff0c\u627e\u5230\u4e34\u754c\u70b9\u3002\u4ee5mtu\u4e3a1450\u4e3a\u4f8b\uff0c1450 = 20\u5b57\u8282IP\u5934 + 8\u5b57\u8282icmp\u5934 + 1422\u6570\u636e\uff0c\u5219-s\u6307\u5b9a\u4e3a1422\u53ef\u4ee5\u6b63\u5e38\u901a\u8fc7<\/p>\n

Windows\u4e3b\u673a\u4e2d: \u6267\u884cping x.x.x.x -l 1472 -f\u00a0 \u00a0\/\/x.x.x.x\u662f\u76ee\u6807\u5730\u5740
\n-l\u6307\u660eicmp\u62a5\u6587\u7684\u6570\u636e\u90e8\u5206\u5927\u5c0f(\u4e0d\u5305\u542bicmp 8\u5b57\u8282\u5934\u90e8)
\n-f\u8868\u793a\u4e0d\u5141\u8bb8\u5206\u7247\u3002<\/p>\n

traceroute --mtu www.baidu.com<\/p>\n

traceroute to www.baidu.com (14.215.177.39), 30 hops max, 65000 byte packets
\n1 192.168.109.1 (192.168.109.1) 3.063 ms F=1500 2.908 ms *
\n2 192.168.98.36 (192.168.98.36) 1.686 ms 1.422 ms *
\n3 113.98.59.57 (113.98.59.57) 7.075 ms 7.544 ms 5.851 ms<\/p>\n

\u53c2\u8003\uff1a<\/p>\n

ping -s 1400 -M do www.baidu.com
\nPING www.a.shifen.com (153.3.238.102) 1400(1428) bytes of data.\u00a0 \u00a0 \/\/1400+28\u5b57\u8282\u62a5\u6587\u5934
\nping: local error: Message too long, mtu=1418
\nping: local error: Message too long, mtu=1418
\nping: local error: Message too long, mtu=1418
\n^C
\n--- www.a.shifen.com ping statistics ---
\n3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2052ms<\/p>\n

\u4e3a\u4ec0\u4e48mtu\u503c\u662f\u63a2\u6d4b\u51fa\u6765\u7684\u503c\u52a0\u4e0a28?<\/h3>\n

\u56e0\u4e3aping\u4f7f\u7528icmp\u534f\u8bae\uff0c\u4f60\u6307\u5b9a\u7684\u63a2\u6d4b\u503c\u662f\u6570\u636e\u5305\u6570\u636e\u51c0\u8377\u7684\u957f\u5ea6\uff0c\u8fd8\u9700\u8981\u52a0\u4e0a20\u5b57\u8282\u7684ip\u5934\u90e8\uff0c\u548c8\u5b57\u8282\u7684icmp\u5c01\u88c5\u3002<\/p>\n

\u5176\u4ed6\u89e3\u51b3\u65b9\u6cd5<\/h3>\n

-j TCPMSS --set-mss mut-vaue<\/p>\n

\u7528\u6cd5\uff1aiptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -jTCPMSS --set-mss 128
\n\u8fd9\u6761\u89c4\u5219\u7684\u76ee\u7684\u662f\u8bbe\u7f6eMSS\u4e3a128\uff0c\u4eba\u5de5\u8bbe\u7f6e\u4e3a\u5b9a\u503c<\/p>\n","protected":false},"excerpt":{"rendered":"

\u4ec0\u4e48\u662fMTU\uff1f \u7f51\u7edc\u5c42\u53d1\u9001\u6570\u636e\u5305\u662f\u6709\u6700\u5927\u957f\u5ea6\u7684\uff0c\u7f51\u7edc\u5c42\u4ece\u4f20\u8f93\u5c42\u63a5\u6536\u5230\u8981\u53d1\u9001\u7684\u6570\u636e\u5305\u65f6\uff0c\u5b83\u8981\u5224\u65ad\u5411\u672c\u5730\u54ea\u4e2a\u63a5\u53e3\u53d1\u9001\u6570\u636e\uff0c\u5e76\u67e5\u8be2\u8be5\u63a5\u53e3\u83b7\u5f97\u5176\u6700\u5927\u4f20\u8f93\u5355\u5143MTU\uff08MaximumTransmissionUnit\uff09\uff0c\u7f51\u7edc\u5c42\u628aMTU\u503c\u4e0e\u8981\u53d1\u9001\u7684IP\u6570\u636e […]<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"topic":[],"class_list":["post-480","post","type-post","status-publish","format-standard","hentry","category-8"],"_links":{"self":[{"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/posts\/480","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=480"}],"version-history":[{"count":5,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/posts\/480\/revisions"}],"predecessor-version":[{"id":485,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/posts\/480\/revisions\/485"}],"wp:attachment":[{"href":"https:\/\/idc.birk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=480"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=480"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=480"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftopic&post=480"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}