{"id":476,"date":"2015-11-26T14:41:10","date_gmt":"2015-11-26T14:41:10","guid":{"rendered":"http:\/\/598b3e71ec378bd83e0a727608b5db01"},"modified":"2018-05-27T23:57:51","modified_gmt":"2018-05-27T15:57:51","slug":"tcp%e7%8a%b6%e6%80%81%e8%bd%ac%e6%8d%a2%e5%9b%be","status":"publish","type":"post","link":"https:\/\/www.xiaobo.li\/notes\/archives\/476","title":{"rendered":"TCP\u72b6\u6001\u8f6c\u6362\u56fe"},"content":{"rendered":"<p>Linux\u5185\u6838\u534f\u8bae\u6808\u4e3a\u4e00\u4e2atcp\u8fde\u63a5\u7ba1\u7406\u4f7f\u7528\u4e24\u4e2a\u961f\u5217\uff0c\u4e00\u4e2a\u662f\u534a\u94fe\u63a5\u961f\u5217\uff08\u7528\u6765\u4fdd\u5b58\u5904\u4e8eSYN_SENT\u548cSYN_RECV\u72b6\u6001\u7684\u8bf7\u6c42\uff09\uff0c\u4e00\u4e2a\u662faccpetd\u961f\u5217\uff08\u7528\u6765\u4fdd\u5b58\u5904\u4e8eestablished\u72b6\u6001\uff0c\u4f46\u662f\u5e94\u7528\u5c42\u6ca1\u6709\u8c03\u7528accept\u53d6\u8d70\u7684\u8bf7\u6c42\uff09\u3002<\/p>\n<p>\u7b2c\u4e00\u4e2a\u961f\u5217\u7684\u957f\u5ea6\u662f\/proc\/sys\/net\/ipv4\/tcp_max_syn_backlog\uff0c\u9ed8\u8ba4\u662f1024\u3002\u5982\u679c\u5f00\u542f\u4e86syncookies\uff0c\u90a3\u4e48\u57fa\u672c\u4e0a\u6ca1\u6709\u9650\u5236\u3002<\/p>\n<p>\u7b2c\u4e8c\u4e2a\u961f\u5217\u7684\u957f\u5ea6\u662f\/proc\/sys\/net\/core\/somaxconn\uff0c\u9ed8\u8ba4\u662f128\uff0c\u8868\u793a\u6700\u591a\u6709129\u4e2aestablished\u94fe\u63a5\u7b49\u5f85accept\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>windows :<br \/>\nTCPView<br \/>\n<a href=\"https:\/\/technet.microsoft.com\/en-us\/sysinternals\/bb897437.aspx\" target=\"_blank\" rel=\"noopener\">https:\/\/technet.microsoft.com\/en-us\/sysinternals\/bb897437.aspx<\/a><\/p>\n<p>Linux \u5404\u72b6\u6001\u67e5\u770b\u547d\u4ee4\uff1a<\/p>\n<p>netstat -ant|fgrep \":\"|cut -b 77-90|sort |uniq -c<\/p>\n<p>\u72b6\u6001\u8f6c\u6362\u56fe\u4e2d\u72b6\u6001\u7684\u63cf\u8ff0:<br \/>\nCLOSED\uff1a\u65e0\u8fde\u63a5\u662f\u6d3b\u52a8\u7684\u6216\u6b63\u5728\u8fdb\u884c<br \/>\nLISTEN\uff1a\u670d\u52a1\u5668\u5728\u7b49\u5f85\u8fdb\u5165\u547c\u53eb<br \/>\nSYN_RECV\uff1a\u4e00\u4e2a\u8fde\u63a5\u8bf7\u6c42\u5df2\u7ecf\u5230\u8fbe\uff0c\u7b49\u5f85\u786e\u8ba4<br \/>\nSYN_SENT\uff1a\u5e94\u7528\u5df2\u7ecf\u5f00\u59cb\uff0c\u6253\u5f00\u4e00\u4e2a\u8fde\u63a5<br \/>\nESTABLISHED\uff1a\u6b63\u5e38\u6570\u636e\u4f20\u8f93\u72b6\u6001<br \/>\nFIN_WAIT1\uff1a\u5e94\u7528\u8bf4\u5b83\u5df2\u7ecf\u5b8c\u6210<br \/>\nFIN_WAIT2\uff1a\u53e6\u4e00\u8fb9\u5df2\u540c\u610f\u91ca\u653e<br \/>\nITMED_WAIT\uff1a\u7b49\u5f85\u6240\u6709\u5206\u7ec4\u6b7b\u6389<br \/>\nCLOSING\uff1a\u4e24\u8fb9\u540c\u65f6\u5c1d\u8bd5\u5173\u95ed<br \/>\nTIME_WAIT\uff1a\u53e6\u4e00\u8fb9\u5df2\u521d\u59cb\u5316\u4e00\u4e2a\u91ca\u653e<br \/>\nLAST_ACK\uff1a\u7b49\u5f85\u6240\u6709\u5206\u7ec4\u6b7b\u6389<br \/>\nTCP\/IP\u72b6\u6001\u8f6c\u6362\u56fe\u7684\u5206\u6790<br \/>\n\u5176\u4e2d\uff0cEATABLISHED\u662f\u6570\u636e\u7684\u4f20\u9001\u72b6\u6001\u3002\u6211\u4eec\u4e3b\u8981\u5206\u6790\u4e3b\u52a8\u5173\u95ed\u8fd9\u4e2a\u6846\u5185\u7684\u8f6c\u6362\u72b6\u6001\u3002<br \/>\n\u5f53\u5ba2\u6237\u7aef\u5e94\u7528\u7a0b\u5e8f\u4e3b\u52a8\u8bf7\u6c42\u5173\u95ed\u65f6\uff0c\u8c03\u7528close\u6216shutdown\u5173\u95ed\u8fde\u63a5\uff0c\u8fd9\u65f6\u5e94\u7528\u7a0b\u5e8f\u53d1\u9001FIN\uff0c\u7136\u540e\u8fdb\u5165FIN_WAIT_1\u72b6\u6001\uff0c\u7b49\u5f85\u670d\u52a1\u5668\u7aef\u53d1\u9001\u786e\u8ba4\u5305ACK\uff0c\u63a5\u53d7\u5230\u670d\u52a1\u5668\u7aef\u7684ACK\u4ee5\u540e\uff0c\u7136\u540e\u5ba2\u6237\u7aef\u8fdb\u5165FIN_WAIT_2\u72b6\u6001\uff0c\u7b49\u5f85\u670d\u52a1\u5668\u7aef\u8c03\u7528close\uff0c\u5e76\u53d1\u9001FIN\uff0c\u5f53\u5ba2\u6237\u7aef\u63a5\u53d7\u5230FIN\u540e\uff0c\u53d1\u9001ACK\uff0c\u8fdb\u5165\u6700\u7ec8\u7684TIME_WAIT\u72b6\u6001\uff0c\u8fd9\u7ed3\u5408\u7740TCP\u5173\u95ed\u8fde\u63a5\u65f6\u7684\u5206\u7ec4\u4ea4\u6362\u8fde\u63a5\u56fe\u53ef\u4ee5\u66f4\u52a0\u7684\u660e\u767d\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u6267\u884c\u4e3b\u52a8\u5173\u95ed\u7684\u90a3\u4e00\u7aef\u8fdb\u5165TIME_WAIT\u72b6\u6001\u3002\u7559\u5728TIME_WAIT\u7684\u6301\u7eed\u7684\u65f6\u95f4\u662fMSL\uff08\u6700\u957f\u5206\u8282\u751f\u547d\u5468\u671f maximum segment lifttime\uff09\u65f6\u95f4\u7684\u4e24\u500d\uff0c\u4e5f\u5c31\u662f2MSL. MSL\u4e00\u822c\u60c5\u51b5\u4e0b\u662f30\u79d2\u52302\u5206\u79cd\uff0c\u6240\u4ee5TIME_WAIT\u7684\u65f6\u95f4\u4e00\u822c\u4e3a1-4\u5206\u79cd\u3002<\/p>\n<p>&nbsp;<\/p>\n<p><a id=\"ematt:375\" href=\"\/notes\/content\/uploadfile\/201511\/b5e91448520203.gif\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"\/notes\/content\/uploadfile\/201511\/b5e91448520203.gif\" alt=\"\u70b9\u51fb\u67e5\u770b\u539f\u56fe\" border=\"0\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><a id=\"ematt:373\" href=\"\/notes\/content\/uploadfile\/201511\/fb5c1448520097.png\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"\/notes\/content\/uploadfile\/201511\/fb5c1448520097.png\" alt=\"\u70b9\u51fb\u67e5\u770b\u539f\u56fe\" border=\"0\" \/><\/a><\/p>\n<p><a id=\"ematt:373\" href=\"\/notes\/content\/uploadfile\/201511\/fb5c1448520097.png\" target=\"_blank\" rel=\"noopener\"><\/a><a id=\"ematt:374\" href=\"\/notes\/content\/uploadfile\/201511\/10fb1448520097.png\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" src=\"\/notes\/content\/uploadfile\/201511\/10fb1448520097.png\" alt=\"\u70b9\u51fb\u67e5\u770b\u539f\u56fe\" width=\"654\" height=\"546\" border=\"0\" \/><\/a><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1049 size-full\" src=\"https:\/\/www.xiaobo.li\/notes\/wp-content\/uploads\/2015\/11\/01.jpg\" alt=\"\" width=\"574\" height=\"627\" srcset=\"https:\/\/www.xiaobo.li\/notes\/wp-content\/uploads\/2015\/11\/01.jpg 574w, https:\/\/www.xiaobo.li\/notes\/wp-content\/uploads\/2015\/11\/01-275x300.jpg 275w\" sizes=\"auto, (max-width: 574px) 100vw, 574px\" \/> <img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1050 size-full\" src=\"https:\/\/www.xiaobo.li\/notes\/wp-content\/uploads\/2015\/11\/02.jpg\" alt=\"\" width=\"762\" height=\"570\" srcset=\"https:\/\/www.xiaobo.li\/notes\/wp-content\/uploads\/2015\/11\/02.jpg 762w, https:\/\/www.xiaobo.li\/notes\/wp-content\/uploads\/2015\/11\/02-300x224.jpg 300w, https:\/\/www.xiaobo.li\/notes\/wp-content\/uploads\/2015\/11\/02-624x467.jpg 624w\" sizes=\"auto, (max-width: 762px) 100vw, 762px\" \/><\/p>\n<p>\u4e0b\u9762\u662f\uff08\u300aUnix \u7f51\u7edc\u7f16\u7a0b\u7b2c\u4e00\u5377\u300b\u5173\u4e8eTIME_WAIT\u72b6\u6001\u5b58\u5728\u7684\u7406\u7531\uff09<br \/>\n\u5b58\u5728TIME_WAIT\u72b6\u6001\u6709\u4e24\u4e2a\u7406\u7531\uff1a<br \/>\n1.\u00a0 \u5b9e\u73b0\u7ec8\u6b62TCP\u5168\u53cc\u5de5\u8fde\u63a5\u7684\u53ef\u9760\u6027<br \/>\n\u5047\u8bbe\u6700\u7ec8\u7684ACK\u4e22\u5931\uff0c\u670d\u52a1\u5668\u5c06\u91cd\u53d1\u6700\u7ec8\u7684FIN,\u56e0\u6b64\u5ba2\u6237\u5fc5\u987b\u7ef4\u62a4\u72b6\u6001\u4fe1\u606f\u4ee5\u5141\u8bb8\u5b83\u91cd\u53d1\u6700\u7ec8\u7684ACK\uff0c\u5982\u679c\u4e0d\u7ef4\u62a4\u72b6\u6001\u4fe1\u606f\uff0c\u5b83\u5c06\u54cd\u5e94\u4ee5RST\uff0c\u800c\u670d\u52a1\u5668\u5219\u628a\u8be5\u5206\u8282\u89e3\u91ca\u6210\u4e00\u4e2a\u9519\u8bef\uff0c\u5982\u679cTCP\u6253\u7b97\u6267\u884c\u6240\u6709\u5fc5\u8981\u7684\u5de5\u4f5c\u4ee5\u5f7b\u5e95\u7ec8\u6b62\u67d0\u4e2a\u8fde\u63a5\u4e0a\u4e24\u4e2a\u65b9\u5411\u7684\u6570\u636e\u6d41\uff0c\u90a3\u4e48\u5b83\u5fc5\u987b\uff0c\u80fd\u591f\u5904\u7406\u8fde\u63a5\u7ec8\u6b62\u5e8f\u5217\u56db\u4e2a\u5206\u8282\u4e2d\u4efb\u4f55\u4e00\u4e2a\u5206\u8282\u7684\u4e22\u5931\u7684\u60c5\u51b5\uff0c\u4e3b\u52a8\u5173\u95ed\u7684\u90a3\u4e00\u7aef\u5fc5\u987b\u8fdb\u5165TIME_WAIT\u72b6\u6001\uff0c\u56e0\u4e3a\u5b83\u53ef\u80fd\u4e0d\u5f97\u4e0d\u91cd\u53d1\u6700\u7ec8\u7684ACK\u3002<br \/>\n2.\u00a0 \u5141\u8bb8\u8001\u7684\u91cd\u590d\u5206\u8282\u7684\u7f51\u7edc\u4e2d\u6d88\u5931\u3002<\/p>\n<p>\u6211\u4eec\u5047\u8bbe206.62.226.33\u7aef\u53e31500\u548c198.162.10.2\u7aef\u53e321\u4e4b\u95f4\u6709\u4e00\u4e2aTCP\u8fde\u63a5\uff0c\u6211\u4eec\u5173\u95ed\u8fd9\u4e2a\u8fde\u63a5\u540e\uff0c\u5728\u4ee5\u540e\u67d0\u4e2a\u65f6\u5019\u53c8\u91cd\u65b0\u5efa\u7acb\u8d77\u76f8\u540c\u7684IP\u5730\u5740\u548c\u7aef\u53e3\u4e4b\u95f4\u7684TCP\u8fde\u63a5\u3002\u540e\u4e00\u4e2a\u8fde\u63a5\u79f0\u4e3a\u524d\u4e00\u4e2a\u8fde\u63a5\u7684\u5316\u8eab\uff0c\u56e0\u4e3a\u5b83\u4eec\u7684IP\u5730\u575b\u548c\u7aef\u53e3\u53f7\u662f\u76f8\u540c\u7684\uff0cTCP\u5fc5\u987b\u9632\u6b62\u6765\u81ea\u67d0\u4e2a\u8fde\u63a5\u7684\u8001\u91cd\u590d\u5206\u7ec4\u5728\u8fde\u63a5\u7ec8\u6b62\u540e\u518d\u73b0\uff0c\u4ece\u800c\u88ab\u8bef\u89e3\u6210\u5c5e\u4e8e\u540c\u4e00\u4e2a\u8fde\u63a5\u7684\u5316\u8eab\u3002\u8981\u5b9e\u73b0\u8fd9\u79cd\u529f\u80fdTCP\u4e0d\u80fd\u7ed9\u5904\u4e8eTIME_WAIT\u72b6\u6001\u7684\u542f\u52a8\u65b0\u7684\u5316\u8eab\uff0c\u65e2\u7136TIME_WAIT\u72b6\u6001\u7684\u5f85\u7eed\u65f6\u95f4\u662f2MLS,\u8fd9\u5c31\u8db3\u591f\u8ba9\u67d0\u4e2a\u65b9\u5411\u4e0a\u7684\u5206\u7ec4\u6700\u591a\u5b58\u6d3bMSL\u79d2\u5373\u88ab\u4e22\u5f03\uff0c\u53e6\u4e00\u4e2a\u65b9\u5411\u4e0a\u7684\u5e94\u7b54\u6700\u591a\u5b58\u6d3bMSL\u79d2\u4e5f\u88ab\u4e22\u5f03\uff0c\u901a\u8fc7\u5b9e\u65bd\u8fd9\u4e2a\u89c4\u5219\uff0c\u6211\u4eec\u5c31\u80fd\u4fdd\u8bc1\u5f53\u6210\u529f\u5efa\u7acb\u4e00\u4e2aTCP\u8fde\u63a5\u65f6\uff0c\u6765\u81ea\u8be5\u8fde\u63a5\u5148\u524d\u7684\u5316\u8eab\u7684\u8001\u91cd\u590d\u5206\u7ec4\u90fd\u5df2\u5728\u7f51\u7edc\u4e2d\u6d88\u901d\u4e86<\/p>\n<p>\u53c2\u8003\u56fe2\uff1a<\/p>\n<p><a id=\"ematt:481\" href=\"\/notes\/content\/uploadfile\/201701\/67b11484623531.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" src=\"\/notes\/content\/uploadfile\/201701\/67b11484623531.jpg\" alt=\"\u70b9\u51fb\u67e5\u770b\u539f\u56fe\" width=\"621\" height=\"452\" border=\"0\" \/><\/a><\/p>\n<p><a id=\"ematt:482\" href=\"\/notes\/content\/uploadfile\/201701\/1b411484623726.png\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" src=\"\/notes\/content\/uploadfile\/201701\/1b411484623726.png\" alt=\"\u70b9\u51fb\u67e5\u770b\u539f\u56fe\" width=\"606\" height=\"389\" border=\"0\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>\u53c2\u8003\uff1ahttp:\/\/www.cnxct.com\/coping-with-the-tcp-time_wait-state-on-busy-linux-servers-in-chinese-and-dont-enable-tcp_tw_recycle\/<\/p>\n<p><b>\u5176\u5b83TCP\u72b6\u6001\u8f6c\u6362\u56fe\u4e00\uff1a<\/b><br \/>\n<a href=\"\/notes\/content\/uploadfile\/201705\/d2b51493650152.png\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" title=\"\u70b9\u51fb\u67e5\u770b\u539f\u56fe\" src=\"\/notes\/content\/uploadfile\/201705\/d2b51493650152.png\" alt=\"\u70b9\u51fb\u67e5\u770b\u539f\u56fe\" width=\"450\" border=\"0\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp;Linux\u5185\u6838\u534f\u8bae\u6808\u4e3a\u4e00\u4e2atcp\u8fde\u63a5\u7ba1\u7406\u4f7f\u7528\u4e24\u4e2a\u961f\u5217\uff0c\u4e00\u4e2a\u662f\u534a\u94fe\u63a5\u961f\u5217\uff08\u7528\u6765\u4fdd\u5b58\u5904\u4e8eSYN_SENT\u548cSYN_RECV\u72b6\u6001\u7684\u8bf7\u6c42\uff09\uff0c\u4e00\u4e2a\u662faccpetd\u961f\u5217\uff08\u7528\u6765\u4fdd\u5b58\u5904\u4e8eestablished\u72b6\u6001\uff0c\u4f46\u662f\u5e94\u7528\u5c42\u6ca1\u6709\u8c03\u7528accept\u53d6\u8d70\u7684\u8bf7\u6c42\uff09\u3002<\/p>\n<p>\u7b2c\u4e00\u4e2a\u961f\u5217\u7684\u957f\u5ea6\u662f\/proc\/sys\/net\/ipv4\/tcp_max_syn_backlog\uff0c\u9ed8\u8ba4\u662f1024\u3002\u5982\u679c\u5f00\u542f\u4e86syncookies\uff0c\u90a3\u4e48\u57fa\u672c\u4e0a\u6ca1\u6709\u9650\u5236\u3002<\/p>\n<p>\u7b2c\u4e8c\u4e2a\u961f\u5217\u7684\u957f\u5ea6\u662f\/proc\/sys\/net\/core\/somaxconn\uff0c\u9ed8\u8ba4\u662f128\uff0c\u8868\u793a\u6700\u591a\u6709129\u4e2aestablished\u94fe\u63a5\u7b49\u5f85accept\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>Linux...<\/p>\n<p> <a href=\"https:\/\/www.xiaobo.li\/notes\/archives\/476\">\u7ee7\u7eed\u9605\u8bfb <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[291],"tags":[225],"class_list":["post-476","post","type-post","status-publish","format-standard","hentry","category-network","tag-tcp"],"_links":{"self":[{"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/posts\/476","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/comments?post=476"}],"version-history":[{"count":0,"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/posts\/476\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/media?parent=476"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/categories?post=476"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/tags?post=476"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}