{"id":2110,"date":"2019-10-19T23:08:59","date_gmt":"2019-10-19T15:08:59","guid":{"rendered":"http:\/\/jc.a300.cn/luyouwang\/?p=2110"},"modified":"2019-10-19T23:08:59","modified_gmt":"2019-10-19T15:08:59","slug":"%e8%b7%af%e7%94%b1%e5%99%a8mtu%e5%80%bc%e5%a4%9a%e5%b0%91%e5%90%88%e9%80%82","status":"publish","type":"post","link":"http:\/\/jc.a300.cn/luyouwang\/2110.html","title":{"rendered":"\u8def\u7531\u5668mtu\u503c\u591a\u5c11\u5408\u9002"},"content":{"rendered":"

MTU\u662fMaximum Transmission Unit\u7684\u7f29\u5199\u3002
\u610f\u601d\u662f\u7f51\u7edc\u4e0a\u4f20\u9001\u7684\u6700\u5927\u6570\u636e\u5305\u3002MTU\u7684\u5355\u4f4d\u662f\u5b57\u8282\u3002\u5927\u90e8\u5206\u7f51\u7edc\u8bbe\u5907\u7684MTU\u90fd\u662f1500\u3002\u5982\u679c\u672c\u673a\u7684MTU\u6bd4\u7f51\u5173\u7684MTU\u5927\uff0c\u5927\u7684\u6570\u636e\u5305\u5c31\u4f1a\u88ab\u62c6\u5f00\u6765\u4f20\u9001\uff0c\u8fd9\u6837\u4f1a\u4ea7\u751f\u5f88\u591a\u6570\u636e\u5305\u788e\u7247\uff0c\u589e\u52a0\u4e22\u5305\u7387\uff0c\u964d\u4f4e\u7f51\u7edc\u901f\u5ea6\u3002\u628a\u672c\u673a\u7684MTU\u8bbe\u6210\u6bd4\u7f51\u5173\u7684MTU\u5c0f\u6216\u76f8\u540c\uff0c\u5c31\u53ef\u4ee5\u51cf\u5c11\u4e22\u5305\u3002<\/p>\n

\"\"<\/a><\/p>\n

\u800c\u4e00\u822cADSL\u5bbd\u5e26\u7684MTU\u57281450\u4e0e1492\u4e4b\u95f4\uff0c\u7cfb\u7edf\u4e0eISP\u4e4b\u95f4MTU\u7684\u4e0d\u7b26\u5c31\u4f1a\u76f4\u63a5\u5bfc\u81f4\u6570\u636e\u5728\u7f51\u7edc\u4f20\u8f93\u8fc7\u7a0b\u4e2d\u4e0d\u65ad\u5730\u8fdb\u884c\u5206\u5305\u3001\u7ec4\u5305\uff0c\u6d6a\u8d39\u4e86\u5b9d\u8d35\u7684\u4f20\u8f93\u65f6\u95f4\uff0c\u4e5f\u4e25\u91cd\u5f71\u54cd\u4e86\u5bbd\u5e26\u7684\u5de5\u4f5c\u6548\u7387\u3002\u8fd9\u5c31\u8981\u6c42\u6211\u4eec\u5fc5\u987b\u5c06\u672c\u673aMTU\u503c\u8bbe\u4e3a\u4e0eISP\u6240\u4f7f\u7528\u7684MTU\u503c\u4e00\u6837\u540e\u624d\u80fd\u5feb\u901f\u6d4f\u89c8\u7f51\u9875\u3001\u4e0b\u8f7d\u6570\u636e\u3002\u4f46\u662f\uff0c\u6bcf\u4e2a\u5730\u533a\u7684ISP\u6240\u4f7f\u7528\u7684MTU\u503c\u90fd\u4e0d\u76f8\u540c\uff0c\u540c\u65f6ISP\u4e5f\u4f1a\u4e0d\u5b9a\u671f\u5730\u66f4\u6539\u5c40\u7aefMTU\u5927\u5c0f\uff0c\u8fd9\u7ed9\u6211\u4eec\u8bbe\u7f6e\u672c\u673aMTU\u5e26\u6765\u4e86\u5f88\u5927\u7684\u4e0d\u4fbf\uff0c\u90a3\u4e48\u6211\u4eec\u600e\u6837\u624d\u80fd\u77e5\u9053ISP\u7684MTU\u662f\u591a\u5c11\u5462\uff1f\u5176\u5b9e\uff0c\u6211\u4eec\u5e73\u65f6\u6700\u5e38\u7528\u7684Ping\u547d\u4ee4\u5c31\u80fd\u5f88\u65b9\u4fbf\u5730\u5e2e\u6211\u4eec\u6d4b\u8bd5\u51fa\u672c\u5730ISP\u7684MTU\u5927\u5c0f\uff0c\u5982\u679c\u5927\u5bb6\u611f\u5174\u8da3\uff0c\u5c31\u8bf7\u8ddf\u968f\u7b14\u8005\u4e00\u8d77\u6765\u770b\u770b\u5427\u3002<\/p>\n

\u5982\u4f55\u68c0\u6d4b\u7f51\u5173\u7684MTU\uff1f<\/strong><\/p>\n

\u5728\u672c\u673a\u6253\u5f00dos\u7a97\u53e3\uff0c\u6267\u884c\uff1a
ping -f -l 1452 192.168.1.1
\u5176\u4e2d192.168.1.1\u662f\u7f51\u5173IP\u5730\u5740\uff0c1452\u662f\u6570\u636e\u5305\u7684\u957f\u5ea6\u3002\u8bf7\u6ce8\u610f\uff0c\u4e0a\u9762\u7684\u53c2\u6570\u662f\u201c-l\u201d\uff08\u5c0f\u5199\u7684L\uff09\uff0c\u800c\u4e0d\u662f\u201c-1\u201d\u3002 \u5982\u679c\u80fdping\u901a\uff0c\u8868\u793a\u6570\u636e\u5305\u4e0d\u9700\u8981\u62c6\u5305\uff0c\u53ef\u4ee5\u901a\u8fc7\u7f51\u5173\u53d1\u9001\u51fa\u53bb\u3002 \u5982\u679c\u51fa\u73b0\uff1a<\/p>\n

Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.<\/p><\/blockquote>\n

\u8868\u793a\u6570\u636e\u5305\u9700\u8981\u62c6\u5f00\u6765\u53d1\u9001\u3002\u6b64\u65f6\uff0c\u51cf\u5c11\u6570\u636e\u5305\u957f\u5ea6\uff0c\u518d\u6267\u884c\u4e0a\u9762\u7684ping\u547d\u4ee4\u3002\u4ece1400\u52301472\u4e4b\u95f4\u591a\u8bd5\u51e0\u6b21\uff0c\u5c31\u80fd\u627e\u5230\u5408\u9002\u7684\u6570\u636e\u5305\u957f\u5ea6\u4e86\u3002\u628a\u6570\u636e\u5305\u957f\u5ea6\u52a0\u4e0a\u6570\u636e\u5305\u593428\u5b57\u8282\uff0c\u5c31\u5f97\u5230MTU\u7684\u503c\u3002 \u5982\u679c\u68c0\u6d4b\u5230\u7f51\u5173\u7684MTU\u503c\u662f1500\uff0c\u4e0d\u9700\u8981\u4fee\u6539\u3002\u5982\u679c\u7f51\u5173\u6709\u9632\u706b\u5899ping\u4e0d\u901a\uff0c\u53ef\u4ee5\u8bd5\u8bd5\u76f4\u63a5\u628aMTU\u8bbe\u4e3a1400\u3002<\/p>\n

C:\\Documents and Settings\\Administrator>ping -f -l 1452 192.168.1.1
Pinging 192.168.1.1 with 1452 bytes of data:
Reply from 192.168.1.1: bytes=1452 time=5ms TTL=64
Reply from 192.168.1.1: bytes=1452 time=5ms TTL=64
Reply from 192.168.1.1: bytes=1452 time=5ms TTL=64
Reply from 192.168.1.1: bytes=1452 time=1ms TTL=64<\/p><\/blockquote>\n

\u7ed3\u679c\u51fa\u73b0\u4e86\u56de\u5e94\u4e86\uff01\u8fd9\u8868\u793a\u8fd9\u4e00\u4e2a MTU \u503c\u662f\u53ef\u884c\u7684\uff01\u4e0d\u8fc7\uff0c\u5f3a\u70c8\u5efa\u8bae\u627e\u51fa\u53ef\u884c\u7684\u6700\u5927 MTU \u503c\uff01\u8fd9\u6837\u4e00\u6765\uff0c\u5728\u8bbe\u5b9a\u7684\u65f6\u5019\uff0c\u624d\u53ef\u4ee5\u8fbe\u5230\u6700\u4f73\u7684\u7f51\u901f\uff01<\/p>\n

\u627e\u51fa MTU \u503c\uff1a\u5229\u7528\u4e0a\u9762\u8fd9\u4e2a\u65b9\u6cd5\u627e\u5230\u7684\u6570\u503c\u8fd8\u4e0d\u662f MTU \u5594\uff01\u7531\u4e8e\u4e00\u4e9b\u5c01\u5305\u4e0a\u9762\u7684\u95ee\u9898\uff0c\u4e0a\u9762\u8fd9\u4e2a\u503c\u518d\u52a0\u4e0a 28 \u624d\u662f\u6211\u4eec\u6240\u9700\u8981\u7684 MTU \u503c\uff01\u6240\u4ee5\uff0c\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u6240\u9700\u8981\u7684 MTU \u503c\u662f 1464+28=1492\uff01<\/p>\n

\u9644\u6ce8\uff1a\u6211\u8bbe\u7f6e\u4e3a1452+28=1480\u540e\uff0c\u8fd8\u662f\u4f1a\u51fa\u73b0\u6709\u4e9b\u7f51\u7ad9\u6253\u4e0d\u5f00\u3001\u8fdc\u7a0b\u684c\u9762\u65e0\u6cd5\u901a\u8fc7\u57df\u540d\u767b\u9646\u7684\u95ee\u9898\uff08\u901a\u8fc7ip\u53ef\u4ee5\u6b63\u5e38\u8fdc\u7a0b\u684c\u9762\u767b\u9646\uff09\uff0c\u800c\u628aMTU\u8bbe\u7f6e\u4e3a1452\u540e\uff0c\u53cd\u800c\u8fd9\u4e9b\u95ee\u9898\u90fd\u8fce\u5203\u800c\u89e3\u4e86\uff0c\u5e76\u4e14\uff0c\u6b64\u65f6\uff0c\u767b\u9646zlbog\u540e\u53f0\u6b63\u5e38\u3001\u4f7f\u7528\u57df\u540d\u767b\u9646\u8fdc\u7a0b\u684c\u9762\u6b63\u5e38\u3002<\/p>\n

\u4e00\u822c\u6765\u8bb2\uff0c\u8bbe\u8ba1\u597d\u672c\u673a\u7684MTU\u503c\uff0c\u53ef\u4ee5\u89e3\u51b3\u90e8\u5206\u7f51\u7ad9\u6253\u4e0d\u5f00\u7684\u60c5\u51b5\uff0c\u4f46\u662f\u5982\u679c\u4f60\u7684\u5171\u4eab\u4e3b\u673a\u6216\u8def\u7531\u5668\u7684MTU\u8bbe\u7f6e\u6709\u95ee\u9898\uff0c\u6709\u65f6\u95ee\u9898\u4ecd\u7136\u5b58\u6216\uff0c\u6216\u8005\u51fa\u73b0\u7f51\u901f\u8fc7\u6162\u7684\u60c5\u51b5\u3002\u5408\u7406\u7684\u8bbe\u7f6e\u8def\u7531\u5668\u4e0e\u672c\u673a\u7684MTU\u503c\uff0c\u5c31\u53ef\u4ee5\u5b8c\u5168\u89e3\u51b3\u4e0a\u8ff0\u95ee\u9898\uff0c\u4f7f\u4e0a\u7f51\u901f\u5ea6\u8fbe\u5230\u6700\u5927\u5316\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

MTU\u662fMaximum Transmission Unit\u7684\u7f29\u5199\u3002\u610f\u601d\u662f\u7f51\u7edc\u4e0a\u4f20\u9001\u7684\u6700\u5927\u6570\u636e\u5305\u3002MTU\u7684\u5355\u4f4d\u662f\u5b57\u8282\u3002\u5927\u90e8\u5206\u7f51\u7edc\u8bbe\u5907\u7684MTU\u90fd\u662f1500\u3002\u5982\u679c\u672c\u673a\u7684MTU\u6bd4\u7f51\u5173\u7684MT\u2026<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[424,426,425],"attr":[],"class_list":{"0":"post-2110","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"hentry","6":"category-luyouqi","7":"tag-mtu","10":"entry"},"views":8624,"_links":{"self":[{"href":"http:\/\/jc.a300.cn/luyouwang\/wp-json\/wp\/v2\/posts\/2110","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/jc.a300.cn/luyouwang\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/jc.a300.cn/luyouwang\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/jc.a300.cn/luyouwang\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/jc.a300.cn/luyouwang\/wp-json\/wp\/v2\/comments?post=2110"}],"version-history":[{"count":0,"href":"http:\/\/jc.a300.cn/luyouwang\/wp-json\/wp\/v2\/posts\/2110\/revisions"}],"wp:attachment":[{"href":"http:\/\/jc.a300.cn/luyouwang\/wp-json\/wp\/v2\/media?parent=2110"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/jc.a300.cn/luyouwang\/wp-json\/wp\/v2\/categories?post=2110"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/jc.a300.cn/luyouwang\/wp-json\/wp\/v2\/tags?post=2110"},{"taxonomy":"attr","embeddable":true,"href":"http:\/\/jc.a300.cn/luyouwang\/wp-json\/wp\/v2\/attr?post=2110"}],"curies":[{"name":"wp","href":"http:\/\/api.w.org\/{rel}","templated":true}]}}