{"id":256,"date":"2019-10-19T18:44:21","date_gmt":"2019-10-19T10:44:21","guid":{"rendered":"http:\/\/www.subingkang.com\/?p=256"},"modified":"2025-08-06T13:55:00","modified_gmt":"2025-08-06T05:55:00","slug":"tcp-ip-%e7%9f%a5%e8%af%86%e7%82%b9%e6%95%b4%e7%90%86","status":"publish","type":"post","link":"https:\/\/subk.me\/?p=256","title":{"rendered":"TCP\/IP \u77e5\u8bc6\u70b9\u6574\u7406"},"content":{"rendered":"<h4 id=\"\u5f15\u8a00\">\u5f15\u8a00<\/h4>\n<p>\u5728\u9605\u8bfb tornado.iostream \u6a21\u5757\u65f6\u6d89\u53ca\u5230\u4e00\u4e9b\u7f51\u7edc\u5f02\u5e38\u7684\u5904\u7406\uff0c\u5728\u6df1\u5165\u4e86\u89e3\u5f02\u5e38\u7684\u5b9a\u4e49\u548c\u5904\u7406\u540e\uff0c\u89c9\u5f97\u6709\u5fc5\u8981\u5bf9 TCP\/IP \u534f\u8bae\u505a\u4e00\u4e2a\u7b80\u5355\u7684\u590d\u4e60\u6574\u7406\uff0c\u5c24\u5176\u9488\u5bf9\u76f4\u63a5\u6d89\u53ca socket \u7f16\u7a0b\u7684 TCP \u534f\u8bae\u90e8\u5206\u3002<\/p>\n<p>\u4ee5\u4e0b\u603b\u7ed3\u7684\u5185\u5bb9\u4f9d\u6b21\u4ece TCP\/IP \u7684\u5206\u5c42\u7ed3\u6784\u3001\u6570\u636e\u5c01\u88c5\u4e0e\u5206\u7528\u3001\u4ee5\u592a\u7f51\u5e27\u7ed3\u6784\u3001IP \u6570\u636e\u5305\u7ed3\u6784\u3001TCP \u6570\u636e\u6bb5\uff08\u6216\u62a5\u6587\u6bb5\uff09\u7ed3\u6784\u6765\u8fdb\u884c\uff0c\u5e76\u4e13\u95e8\u5bf9 TCP \u7684\u4e09\u6b21\u63e1\u624b\u548c\u56db\u6b21\u6325\u624b\u505a\u4e00\u4e2a\u8f83\u4e3a\u8be6\u7ec6\u7684\u4ecb\u7ecd\u3002<\/p>\n<h4 id=\"TCP-IP-\u534f\u8bae\">TCP\/IP \u534f\u8bae<\/h4>\n<h5 id=\"TCP-IP-\u7684\u5206\u5c42\u7ed3\u6784\">TCP\/IP \u7684\u5206\u5c42\u7ed3\u6784<\/h5>\n<p>OSI (Open System Interconnect, \u5f00\u653e\u7cfb\u7edf\u4e92\u8fde\u53c2\u8003\u6a21\u578b)\u4e3a\u5f00\u653e\u5f0f\u4e92\u8fde\u4fe1\u606f\u7cfb\u7edf\u63d0\u4f9b\u4e86\u4e00\u79cd\u7406\u8bba\u4e0a\u7684\u7f51\u7edc\u6a21\u578b\uff0c\u800c TCP\/IP \u5219\u662f\u5b9e\u9645\u5b9e\u73b0\u8fd0\u884c\u7684\u7f51\u7edc\u6a21\u578b\u3002TCP\/IP \u91c7\u7528\u56db\u5c42\u7ed3\u6784\uff0c\u5b83\u4e0e OSI \u4e03\u5c42\u7ed3\u6784\u7684\u5bf9\u5e94\u5173\u7cfb\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/strawhatfy.github.io\/2015\/07\/30\/TCP-IP-Protocol\/tcp_ip_layers.png\"><\/p>\n<p><strong>\u6ce8\uff1a\u4e0a\u8ff0\u534f\u8bae\u5206\u5c42\u4e0d\u662f\u5b8c\u7f8e\u7684\uff0cICMP\/IGMP \u4f5c\u4e3a IP \u7684\u9644\u5c5e\u534f\u8bae\uff0c\u5176\u6570\u636e\u662f\u5c01\u88c5\u5728 IP \u6570\u636e\u5305\u4e2d\u7684\uff0c\u6240\u4ee5\u5728\u903b\u8f91\u4e0a\u5b83\u4eec\u662f\u5728 IP \u7684\u4e0a\u5c42\uff0c\u8fd9\u4e2a\u5728\u540e\u9762\u6570\u636e\u5206\u7528\u7684\u793a\u610f\u56fe\u4e2d\u4f1a\u4f53\u73b0\uff1bARP\/RARP \u4e5f\u9047\u5230\u540c\u6837\u7684\u95ee\u9898\uff0c\u5b83\u4eec\u4e0e IP \u6570\u636e\u62a5\u4e00\u6837\u90fd\u6709\u5404\u81ea\u7684\u4ee5\u592a\u7f51\u5e27\u7ed3\u6784\uff0c\u4f46\u53c8\u662f\u4e3a IP \u5730\u5740\u8f6c\u6362\u670d\u52a1\u7684\uff0c\u6240\u4ee5\u5728\u903b\u8f91\u4e0a\u5b83\u4eec\u662f\u5728 IP \u7684\u4e0b\u5c42\u3002\u5728\u300aTCP-IP\u8be6\u89e3\u300b\u4e2d\u5c31\u5c06 ARP\/RARP \u5212\u5206\u5230\u7f51\u7edc\u63a5\u53e3\u5c42\u3002\u5728\u8fd9\u4e2a\u56fe\u4e2d\uff0c\u5c06\u8fd9\u51e0\u4e2a\u534f\u8bae\u90fd\u653e\u5728\u4e0e IP \u540c\u4e00\u5c42\u53ea\u662f\u4e3a\u4e86\u9009\u62e9\u4e00\u79cd\u5206\u7c7b\u65b9\u5f0f\uff0c\u4e0d\u662f\u7edd\u5bf9\u7684\u3002<\/strong>\n<br><a id=\"more\"><\/a>\n<br>\u5982\u4e0a\u56fe\u6240\u793a\uff0cTCP\/IP \u5404\u5c42\u7684\u529f\u80fd\u548c\u534f\u8bae\u60c5\u51b5\u53ef\u4ee5\u7b80\u8ff0\u4e3a\uff1a<\/p>\n<ol>\n<li>\n<p>\u7f51\u7edc\u63a5\u53e3\u5c42(Host-to-Net Layer)\uff0c\u5bf9\u5e94 OSI \u4e03\u5c42\u6a21\u578b\u7684\u4e0b\u4e24\u5c42\uff0c\u8d1f\u8d23\u5b9e\u9645\u6570\u636e\u7684\u4f20\u8f93\u3002\u4e3b\u8981\u534f\u8bae\u5305\u62ec\uff1aEthernet\u3001FDDI\u3001PPP\u3001SLIP\u548c\u5176\u4ed6\u80fd\u4f20\u8f93 IP \u6570\u636e\u5305\u7684\u4efb\u4f55\u534f\u8bae\u3002<\/p>\n<\/li>\n<li>\n<p>\u7f51\u9645\u5c42\uff08Inter-network Layer\uff09\uff0c\u5bf9\u5e94 OSI \u4e03\u5c42\u6a21\u578b\u7684\u7b2c\u4e09\u5c42\uff0c\u8d1f\u8d23\u7f51\u7edc\u95f4\u7684\u5bfb\u5740\u548c\u6570\u636e\u4f20\u8f93\u3002\u4e3b\u8981\u534f\u8bae\uff1aIP\u3001ARP\u3001RARP\u3001ICMP\u3001IGMP\u3002<\/p>\n<\/li>\n<li>\n<p>\u4f20\u8f93\u5c42\uff08Transport Layer\uff09\uff0c\u5bf9\u5e94 OSI \u4e03\u5c42\u6a21\u578b\u7684\u7b2c\u56db\u5c42\uff0c\u8d1f\u8d23\u63d0\u4f9b\u53ef\u9760\u7684\u4f20\u8f93\u670d\u52a1\u3002\u4e3b\u8981\u534f\u8bae\u5305\u62ec\uff1aTCP\u3001UDP\u3002<\/p>\n<\/li>\n<li>\n<p>\u5e94\u7528\u5c42\uff08Application Layer\uff09\uff0c\u5bf9\u5e94 OSI \u4e03\u5c42\u6a21\u578b\u7684\u4e0a\u9762\u4e09\u5c42\uff0c\u8d1f\u8d23\u5b9e\u73b0\u4e00\u5207\u4e0e\u5e94\u7528\u7a0b\u5e8f\u76f8\u5173\u7684\u529f\u80fd\u3002\u4e3b\u8981\u534f\u8bae\u5305\u62ec\uff1aFTP\u3001HTTP\u3001DNS\u3001SMTP\u3001NFS\u7b49\u3002<\/p>\n<\/li>\n<\/ol>\n<h5 id=\"\u6570\u636e\u5c01\u88c5\u4e0e\u5206\u7528\">\u6570\u636e\u5c01\u88c5\u4e0e\u5206\u7528<\/h5>\n<p>\u5bf9\u4e8e\u6211\u4eec\u4ecb\u7ecd\u7684 TCP\/IP \u534f\u8bae\uff0c\u53ef\u4ee5\u901a\u8fc7\u300aTCP-IP\u8be6\u89e3\u300b \u7684\u53e6\u4e00\u79cd\u534f\u8bae\u5206\u5c42\u65b9\u5f0f\u6765\u4e00\u89c8\u51e0\u4e2a\u91cd\u8981\u534f\u8bae\u4e4b\u95f4\u7684\u5173\u7cfb\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/strawhatfy.github.io\/2015\/07\/30\/TCP-IP-Protocol\/tcp_ip_layers_other.png\"><\/p>\n<p>\u5bf9\u4e8e\u6570\u636e\u7684\u4e0b\u884c\uff0c\u6211\u4eec\u7b80\u5355\u79f0\u4e3a \u201c\u5c01\u88c5\u201d\uff0c\u53cd\u4e4b\u79f0\u4e3a \u201c\u5206\u7528\u201d\u3002<\/p>\n<p><strong>\u6ce8\uff1a\u636e\u8bf4\u5728\u65e9\u671f DEC-10 \u7cfb\u7edf\u4e0a\u5b57\u8282\u5e76\u4e0d\u662f 8bit \u7684\uff0c\u6240\u4ee5\u6709\u4e9b\u65e9\u671f\u6587\u732e\u4e2d\u7528 octet \u8fd9\u4e2a\u672f\u8bed\u6807\u8bc6\u5b57\u8282\u3002<\/strong><\/p>\n<h6 id=\"\u5c01\u88c5\">\u5c01\u88c5<\/h6>\n<p>\u5e94\u7528\u7a0b\u5e8f\u4f7f\u7528 TCP\/IP \u534f\u8bae\u4f20\u8f93\u5e94\u7528\u6570\u636e\u65f6\u5019\uff0c\u6570\u636e\u8981\u88ab\u9001\u5165\u534f\u8bae\u6808\u7ecf\u8fc7\u9010\u5c42\u5c01\u88c5\uff0c\u6700\u7ec8\u4f5c\u4e3a\u6bd4\u7279\u6d41\u5728\u5a92\u4f53\u4e0a\u4f20\u9001\u51fa\u53bb\u3002\u5176\u8fc7\u7a0b\u793a\u610f\u56fe\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/strawhatfy.github.io\/2015\/07\/30\/TCP-IP-Protocol\/packaging.png\"><\/p>\n<p><strong><br>\u6ce8\uff1a\u4ece\u4e0a\u56fe\u53ef\u4ee5\u770b\u5230\u4ee5\u592a\u7f51\u5e27\u7684\u6570\u636e\u957f\u5ea6\u662f\u6709\u5927\u5c0f\u9650\u5236\u7684\uff0c\u8fd9\u4e2a\u6700\u5927\u503c\u79f0\u4e3a MTU\uff0c\u6240\u4ee5\u5f53 IP \u6570\u636e\u5305\u957f\u5ea6\u5927\u4e8e MTU \u65f6\u4f1a\u88ab\u62c6\u6210\u591a\u4e2a\u5e27\u4f20\u8f93\uff0c\u79f0\u4e3a \u201cIP\u5206\u7247\u201d\u3002<\/strong><\/p>\n<p>\u534f\u8bae\u6808\u4e2d\u7684\u6bcf\u4e00\u5c42\u90fd\u9700\u8981\u5411\u4f20\u56fe\u8be5\u5c42\u7684\u6570\u636e\u6dfb\u52a0\u76f8\u5e94\u7684\u534f\u8bae\u5934\u3002 UDP \u4e0e TCP \u6570\u636e\u7ed3\u6784\u57fa\u672c\u4e00\u81f4\uff0c\u552f\u4e00\u7684\u4e0d\u540c\u662f UDP \u4f20\u7ed9 IP \u7684\u4fe1\u606f\u5355\u5143\u79f0\u4f5c UDP \u6570\u636e\u62a5\uff08UDP datagram\uff09\uff0c\u800c\u4e14 UDP \u7684\u9996\u90e8\u957f\u4e3a 8 \u5b57\u8282\u3002\u8bb8\u591a\u5e94\u7528\u7a0b\u5e8f\u90fd\u4f1a\u4f7f\u7528 TCP\/UDP \u534f\u8bae\uff0c\u6240\u4ee5\u9700\u8981\u5728\u62a5\u6587\u7684\u9996\u90e8\u533a\u5206\u5e94\u7528\u7a0b\u5e8f\uff0c\u8fd9\u4e2a\u533a\u5206\u6807\u8bc6\u5c31\u662f 16bit \u7684\u201c\u7aef\u53e3\u201d\u3002<\/p>\n<p>ICMP\u3001IGMP\u3001TCP\u3001UDP \u90fd\u8981\u4f7f\u7528 IP\uff0c\u6240\u4ee5 IP \u6570\u636e\u5305\u9996\u90e8\u6709\u4e00\u4e2a 8bit \u7684\u6807\u8bc6\u5b57\u6bb5\u4e13\u95e8\u7528\u4e8e\u533a\u5206\uff0c1\u8868\u793a\u4e3a ICMP\uff0c 2\u8868\u793a\u4e3a IGMP\uff0c 6\u8868\u793a\u4e3a TCP \uff0c 17\u8868\u793a\u4e3a UDP\u3002<\/p>\n<p>IP\u3001ARP\u3001RARP \u90fd\u8981\u4f7f\u7528\u4ee5\u592a\u7f51\u5e27\uff0c\u6240\u4ee5\u5e27\u7ed3\u6784\u4e2d\u4e5f\u6709\u4e00\u4e2a\u6807\u8bc6\u5b57\u6bb5\u7528\u4e8e\u6807\u8bc6\u4e0a\u5c42\u534f\u8bae\u3002<\/p>\n<p>TCP\u3001IP\u3001\u4ee5\u592a\u7f51\u5e27\u7684\u6570\u636e\u7ed3\u6784\u5c06\u5728\u540e\u9762\u4ecb\u7ecd\u3002<\/p>\n<h6 id=\"\u5206\u7528\">\u5206\u7528<\/h6>\n<p>\u5f53\u6570\u636e\u88ab\u5a92\u4f53\u9001\u8fbe\u7f51\u7edc\u63a5\u53e3\u5c42\u65f6\uff0c\u4f1a\u6267\u884c\u4e0e \u201c\u5c01\u88c5\u201d \u76f8\u53cd\u7684\u62c6\u5305\u8fc7\u7a0b\uff0c\u6bcf\u5c42\u534f\u8bae\u90fd\u8981\u53bb\u68c0\u67e5\u62a5\u6587\u9996\u90e8\u4e2d\u7684\u534f\u8bae\u6807\u8bc6\uff0c\u5df2\u786e\u5b9a\u63a5\u53d7\u6570\u636e\u7684\u4e0a\u5c42\u534f\u8bae\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u5c31\u662f \u201c\u5206\u7528\u201d\u3002\u5176\u793a\u610f\u56fe\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/strawhatfy.github.io\/2015\/07\/30\/TCP-IP-Protocol\/unpack.png\"><\/p>\n<h5 id=\"\u4ee5\u592a\u7f51\u5e27\u7ed3\u6784\">\u4ee5\u592a\u7f51\u5e27\u7ed3\u6784<\/h5>\n<p><img decoding=\"async\" src=\"https:\/\/strawhatfy.github.io\/2015\/07\/30\/TCP-IP-Protocol\/thernet_frame.png\"><\/p>\n<p>\u5b9e\u9645\u4e0a\u8fd8\u6709\u53e6\u5916\u4e00\u79cd\u5e27\u683c\u5f0f\uff1aIEEE 802.2\/802.3\uff0c\u662f\u5728 RFC 1042 \u4e2d\u5b9a\u4e49\u7684\u3002\u4e0e\u5728 RFC 894 \u5b9a\u4e49\u7684\u4ee5\u592a\u7f51\u5e27\u683c\u5f0f\u7a0d\u5fae\u6709\u4e9b\u4e0d\u540c\uff0c\u4f46\u662f\u5728 TCP\/IP \u7684\u4e16\u754c\u91cc\u540e\u8005\u66f4\u5e38\u89c1\u3002<\/p>\n<p>\u7b80\u5355\u63d0\u4e00\u53e5\uff0cARP\/RARP \u662f\u7528\u4e8e\u5728 32bit \u7684 IP \u5730\u5740\u548c 48bit \u7684 MAC \u5730\u5740\u4e4b\u95f4\u8fdb\u884c\u6620\u5c04\u3002\u5177\u4f53\u534f\u8bae\u5185\u5bb9\u8bf7\u67e5\u9605\u76f8\u5173\u8d44\u6599\u3002<\/p>\n<h5 id=\"IP-\u6570\u636e\u5305\u7ed3\u6784\">IP \u6570\u636e\u5305\u7ed3\u6784<\/h5>\n<p><img decoding=\"async\" src=\"https:\/\/strawhatfy.github.io\/2015\/07\/30\/TCP-IP-Protocol\/ip_package.png\"><\/p>\n<p>\u6ce8\u610f\u4e00\u4e0b\uff0c\u4e0a\u9762\u63cf\u8ff0\u7684\u9996\u90e8\uff0c\u4e0d\u5305\u62ec\u9009\u9879\u5b57\u6bb5\u7684 IP \u5934\u90e8\u957f\u5ea6\u4e3a 20 \u5b57\u8282\u957f\u5ea6\uff0c\u6700\u9ad8\u4f4d\u5728\u5de6\u8fb9\uff0c\u8bb0\u4e3a 0bit\u3002\u6700\u4f4e\u4f4d\u5728\u53f3\u8fb9\uff0c\u8bb0\u4e3a 31bit\u3002\u91c7\u7528 \u201c\u5927\u7aef\u201d \u5b57\u8282\u5e8f\u8fdb\u884c\u4f20\u8f93\uff0c\u4e5f\u5c31\u662f\u5bf9\u4e8e 4 \u5b57\u8282\u7684 32bit \u6570\u636e\uff0c\u4ece\u9ad8\u4f4d\u5b57\u8282\uff080bit\uff09\u5f00\u59cb\u4f20\u8f93 0\uff5e7\uff0c8\uff5e15\uff0c15\uff5e23\uff0c24\uff5e31bit\u3002\u5404\u5b57\u6bb5\u7684\u542b\u4e49\u5982\u4e0b\uff1a<\/p>\n<ul>\n<li>4 \u4f4d\u7248\u672c\u53f7\uff0c\u6307\u534f\u8bae\u7248\u672c\u53f7\uff0c\u503c\u4e3a4\u4ee3\u8868 IPv4\u3002<\/li>\n<li>4 \u4f4d\u9996\u90e8\u957f\u5ea6\uff0c\u6bcf\u4e00\u4e2a\u8ba1\u91cf\u5355\u4f4d\u662f 32bit\uff084 byte\uff09\uff0c\u6307\u7684\u662f\u5305\u62ec\u9009\u9879\u5b57\u6bb5\u5728\u5185\u7684 IP \u9996\u90e8\u957f\u5ea6\uff0c\u7531\u4e8e\u662f 4bit\uff0c\u6240\u4ee5 IP \u9996\u90e8\u6700\u957f\u53ea\u80fd\u662f 60 \u5b57\u8282\uff0815 * 4\uff09\u3002<\/li>\n<li>8 \u4f4d\u670d\u52a1\u7c7b\u578b\uff08TOS\uff09\uff0c\u5305\u62ec 3bit \u4f18\u5148\u6743\u5b57\u6bb5\uff08\u73b0\u5728\u5df2\u7ecf\u4e0d\u7528\u4e86\uff09\uff0c4bit TOS\u5b57\u6bb5\uff0c 1bit \u5907\u7528\u4f4d\u30024bit TOS\u4f4d\u5206\u522b\u4ee3\u8868\uff1a\u6700\u5c0f\u65f6\u5ef6\u3001\u6700\u5927\u541e\u5410\u91cf\u3001\u6700\u9ad8\u53ef\u9760\u6027\u548c\u6700\u5c0f\u8d39\u7528\uff0c\u53ea\u80fd\u8bbe\u7f6e\u5176\u4e2d 1bit\uff0c\u5982\u679c\u6240\u6709 4bit \u5747\u4e3a0\uff0c\u90a3\u4e48\u5c31\u8868\u793a\u662f\u4e00\u822c\u670d\u52a1\u3002<\/li>\n<li>16 \u4f4d IP \u6570\u636e\u5305\u957f\u5ea6\uff0c\u8ba1\u91cf\u5355\u4f4d byte\uff0c\u5305\u62ec\u9996\u90e8\u548c\u6570\u636e\u90e8\u5206\u3002\u80fd\u8868\u793a\u7684\u6700\u5927\u957f\u5ea6\u4e3a 65535\uff0c\u4e14\u8fd9\u4e2a\u5b57\u6bb5\u662f\u5fc5\u987b\u7684\uff0c\u5f53 IP \u6570\u636e\u5305\u5c0f\u4e8e 46 \u5b57\u8282\u65f6\u5728\u4ee5\u592a\u7f51\u5e27\u4e2d\u6570\u636e\u5c06\u4f1a\u88ab\u586b\u5145\u5230 46 \u5b57\u8282\uff0c\u8fd9\u65f6\u5019\u5982\u679c\u6ca1\u6709\u8fd9\u4e2a\u5b57\u6bb5\u6211\u4eec\u63a5\u6536\u5230\u5e27\u540e\u4fbf\u4e0d\u80fd\u5f97\u5230\u6b63\u786e\u7684 IP \u6570\u636e\u5305\u3002<\/li>\n<li>16 \u4f4d\u6807\u8bc6\u5b57\u6bb5\uff0c\u662f\u6570\u636e\u5305\u7684\u552f\u4e00\u6807\u8bc6\uff0c\u901a\u5e38\u4e3b\u673a\u6bcf\u53d1\u9001\u4e00\u4e2a\u6570\u636e\u5305\u5c31\u4f1a +1 \uff0c\u5728\u5206\u7247\u65f6\u4f1a\u88ab\u590d\u5236\u5230\u6bcf\u4e00\u4e2a\u5206\u7247\u4e2d\u3002<\/li>\n<li>3 \u4f4d\u6807\u5fd7\u5b57\u6bb5\u548c 13 \u4f4d(\u7247)\u504f\u79fb\u5b57\u6bb5\uff0c\u7528\u4e8e\u6570\u636e\u5305\u5206\u7247\u548c\u91cd\u7ec4\u30023 \u4f4d\u6807\u5fd7\u5b57\u6bb5\uff0c0bit \u4fdd\u7559\uff1b1bit \u4e3a DF \uff1a0\u8868\u793a\u53ef\u4ee5\u5206\u7247\uff0c1\u8868\u793a\u4e0d\u80fd\u5206\u7247\uff1b2bit \u4e3a MF:0\u8868\u793a\u6700\u540e\u4e00\u4e2a\u5206\u7247\uff0c1\u8868\u793a\u8fd8\u6709\u5206\u7247\u300213 \u4f4d(\u7247)\u504f\u79fb\u5b57\u6bb5\uff0c\u6307\u793a\u4e86\u8fd9\u4e2a\u5206\u7247\u5728\u6240\u5c5e\u6570\u636e\u5305\u4e2d\u7684\u4f4d\u7f6e\uff0c\u5206\u7247\u504f\u79fb\u4ee5 8byte \u505a\u4e3a\u8ba1\u91cf\u5355\u4f4d\uff0c\u7b2c\u4e00\u4e2a\u5206\u7247\u504f\u79fb\u4e3a 0\u3002<\/li>\n<li>8 \u4f4d\u751f\u5b58\u65f6\u95f4(TTL),\u8bbe\u7f6e\u4e86\u6570\u636e\u5305\u53ef\u4ee5\u7ecf\u8fc7\u7684\u6700\u591a\u8def\u7531\u5668\u6570\u91cf\u3002<\/li>\n<li>8 \u4f4d\u534f\u8bae\u5b57\u6bb5\uff0c\u524d\u9762\u5df2\u7ecf\u63d0\u8fc7\u4e86\uff0c\u6807\u8bc6\u4e0a\u5c42\u534f\u8bae\u7684\u5b57\u6bb5\u3002<\/li>\n<li>16 \u4f4d\u9996\u90e8\u6821\u9a8c\u548c\uff0c\u6839\u636e IP \u9996\u90e8\u8ba1\u7b97\u7684\u68c0\u9a8c\u548c\u7801\uff0c\u5b83\u4e0d\u5bf9\u9996\u90e8\u540e\u9762\u7684\u6570\u636e\u8fdb\u884c\u8ba1\u7b97\u3002\u91c7\u7528\u7684\u662f 16bit \u4e8c\u8fdb\u5236\u53cd\u7801\u6c42\u548c\uff0c\u5177\u4f53\u7b97\u6cd5\u8bf7\u67e5\u9605\u8d44\u6599\u3002<\/li>\n<li>32 \u4f4d\u6e90 IP \u5730\u5740\u548c32\u4f4d\u76ee\u6807 IP \u5730\u5740\u3002<\/li>\n<li>\u9009\u9879\u5b57\u6bb5\uff0c\u53ef\u53d8\u957f\u7684\u6570\u636e\u4fe1\u606f\uff0c\u5177\u4f53\u9009\u9879\u5b9a\u4e49\u8bf7\u67e5\u8be2\u76f8\u5173\u6587\u6863\u3002\u5c24\u5176\u6ce8\u610f\u7684\u662f\uff0c\u9009\u9879\u5fc5\u987b\u4ee5 32bit \u4f5c\u4e3a\u8ba1\u91cf\u5355\u4f4d\uff0c\u4e0d\u6ee1 32bit \u9700\u8981\u586b\u5145 0\u3002<\/li>\n<\/ul>\n<h5 id=\"TCP-\u6570\u636e\u6bb5\u7ed3\u6784\">TCP \u6570\u636e\u6bb5\u7ed3\u6784<\/h5>\n<p><img decoding=\"async\" src=\"https:\/\/strawhatfy.github.io\/2015\/07\/30\/TCP-IP-Protocol\/tcp_segment.png\"><\/p>\n<p>\u4e0d\u8ba1\u7b97\u9009\u9879\u5b57\u6bb5\uff0cTCP \u9996\u90e8\u7684\u957f\u5ea6\u4e3a 20byte\u3002<\/p>\n<ul>\n<li>16 \u4f4d\u6e90\u7aef\u53e3\u4e0e\u76ee\u6807\u7aef\u53e3\u53f7\uff0c\u7528\u4e8e\u6807\u8bc6\u53d1\u9001\u7aef\u5e94\u7528\u7a0b\u5e8f\u548c\u63a5\u6536\u7aef\u5e94\u7528\u7a0b\u5e8f\u3002<\/li>\n<li>32 \u4f4d\u5e8f\u53f7\uff0c\u65e0\u7b26\u53f7\u6570\uff0c\u7528\u6765\u6807\u8bc6\u4ece TCP \u53d1\u9001\u7aef\u5411 TCP \u63a5\u6536\u7aef\u53d1\u9001\u7684\u6570\u636e\u5b57\u8282\u6d41\uff0c\u5b83\u8868\u793a\u5728\u8fd9\u4e2a\u62a5\u6587\u6bb5\u4e2d\u7684\u7684\u7b2c\u4e00\u4e2a\u6570\u636e\u5b57\u8282\uff0c\u7b80\u5355\u7684\u53ef\u7406\u89e3\u4e3a\u5bf9\u53d1\u9001\u7684\u6570\u636e\uff08\u8fd9\u4e2a\u6570\u636e\u4e0d\u4e00\u5b9a\u662f\u6307\u6570\u636e\u5b57\u6bb5\u7684\u6570\u636e\uff0c\u6bd4\u5982\u5efa\u7acb\u8fde\u63a5\u65f6 SYN \u5b57\u6bb5\u8bbe\u7f6e\u4e3a 1\uff0c\u4e5f\u4f1a\u6d88\u8017\u4e00\u4e2a\u8ba1\u6570\uff09\u6309 byte \u8fdb\u884c\u5faa\u73af\u8ba1\u6570\u3002<\/li>\n<li>32 \u4f4d\u786e\u8ba4\u5e8f\u53f7\uff0c\u65e0\u7b26\u53f7\u6570\uff0c\u7528\u4e8e\u8868\u793a\u671f\u671b\u6536\u5230\u7684\u4e0b\u4e00\u4e2a\u5e8f\u53f7\uff0cACK=1 \u65f6\u6709\u6548\u3002<\/li>\n<li>4 \u4f4d\u7f6e\u9996\u90e8\u957f\u5ea6\uff0c\u8ba1\u91cf\u5355\u4f4d\u4e3a 32bit\uff0c\u540c IP \u9996\u90e8\u957f\u5ea6\u5b57\u6bb5\u3002<\/li>\n<li>URG\uff0c\u7d27\u6025\u6307\u9488\u6709\u6548\u3002<\/li>\n<li>ACK\uff0c\u786e\u8ba4\u5e8f\u53f7\u6709\u6548\u3002<\/li>\n<li>PSH\uff0c\u63a5\u6536\u65b9\u5e94\u8be5\u5c3d\u5feb\u5c06\u8fd9\u4e2a\u62a5\u6587\u6bb5\u4ea4\u7ed9\u5e94\u7528\u5c42\u3002<\/li>\n<li>RST\uff0c\u91cd\u5efa\u8fde\u63a5\u3002<\/li>\n<li>SYN\uff0c\u540c\u6b65\u5e8f\u53f7\u7528\u6765\u53d1\u8d77\u4e00\u4e2a\u8fde\u63a5\u3002<\/li>\n<li>FIN\uff0c\u53d1\u9001\u7aef\u5b8c\u6210\u53d1\u9001\uff0c\u7528\u6765\u7ed3\u675f\u4e00\u4e2a\u8fde\u63a5\u3002<\/li>\n<li>16 \u4f4d\u7a97\u53e3\u5b57\u6bb5\uff0c\u8fd9\u4e2a\u4e0e TCP \u7684\u6ed1\u52a8\u7a97\u53e3\u6d41\u91cf\u63a7\u5236\u6709\u5173\u3002<\/li>\n<li>16 \u4f4d\u6821\u9a8c\u548c\uff0c\u8986\u76d6\u4e86\u6574\u4e2a\u7684 TCP \u62a5\u6587\u6bb5\uff0c\u5305\u62ec\u9996\u90e8\u548c\u6570\u636e\u3002<strong>\u4e0e UDP \u6570\u636e\u62a5\u4e00\u6837\uff0cTCP \u6570\u636e\u62a5\u6bb5\u5728\u8ba1\u7b97\u6821\u9a8c\u548c\u65f6\u4e5f\u5305\u62ec\u4e00\u4e2a 12 \u5b57\u8282\u957f\u7684\u4f2a\u9996\u90e8<\/strong>\u3002<\/li>\n<li>16 \u4f4d\u7d27\u6025\u6307\u9488\uff0c\u8fd9\u662f\u4e00\u4e2a\u6b63\u5411\u504f\u79fb\u503c\uff0c\u548c\u5e8f\u53f7\u5b57\u6bb5\u4e2d\u7684\u503c\u76f8\u52a0\u8868\u793a\u7d27\u6025\u6570\u636e\u6700\u540e\u4e00\u4e2a\u5b57\u8282\u7684\u5e8f\u53f7\u3002<\/li>\n<li>\u9009\u9879\u5b57\u6bb5\uff0c\u6700\u5e38\u89c1\u7684\u53ef\u9009\u5b57\u6bb5\u662f\u6700\u957f\u62a5\u6587\u5927\u5c0f\uff0c\u53c8\u79f0\u4e3a MSS (Maximum Segment Size)\u3002\u6bcf\u4e2a\u8fde\u63a5\u65b9\u901a\u5e38\u90fd\u5728\u901a\u4fe1\u7684\u7b2c\u4e00\u4e2a\u62a5\u6587\u6bb5\uff08\u4e3a\u5efa\u7acb\u8fde\u63a5\u800c\u8bbe\u7f6e SYN \u6807\u5fd7\u7684\u90a3\u4e2a\u6bb5\uff09\u4e2d\u6307\u660e\u8fd9\u4e2a\u9009\u9879\u3002\u5b83\u6307\u660e\u672c\u7aef\u6240\u80fd\u63a5\u6536\u7684\u6700\u5927\u957f\u5ea6\u7684\u62a5\u6587\u6bb5\u3002<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"https:\/\/strawhatfy.github.io\/2015\/07\/30\/TCP-IP-Protocol\/pseudoheader.png\"><\/p>\n<p>12 \u5b57\u8282\u957f\u7684 TCP\/UDP \u4f2a\u9996\u90e8<\/p>\n<p><strong>\u6ce8\uff1aTCP \u6570\u636e\u62a5\u6bb5\u4f2a\u9996\u90e8\u8d77\u5230\u53cc\u91cd\u6821\u9a8c\u7684\u4f5c\u7528\uff1a1\u3001\u901a\u8fc7\u4f2a\u9996\u90e8\u7684 IP \u5730\u5740\u68c0\u9a8c\uff0cTCP \u53ef\u4ee5\u786e\u8ba4 IP \u6ca1\u6709\u63a5\u53d7\u4e0d\u662f\u53d1\u7ed9\u672c\u673a\u7684\u6570\u636e\u62a5\uff1b2\u3001\u901a\u8fc7\u4f2a\u9996\u90e8\u7684\u534f\u8bae\u5b57\u6bb5\u68c0\u9a8c\uff0cTCP \u53ef\u4ee5\u786e\u8ba4 IP \u6ca1\u6709\u628a\u5e94\u8be5\u4f20\u7ed9\u5176\u4ed6\u9ad8\u5c42\u534f\u8bae\uff08\u6bd4\u5982UDP\u3001ICMP\u6216\u8005IGMP\uff09\u7684\u6570\u636e\u62a5\u4f20\u7ed9 TCP \u3002<\/strong><\/p>\n<h6 id=\"TCP-\u4e09\u6b21\u63e1\u624b\">TCP \u4e09\u6b21\u63e1\u624b<\/h6>\n<p>\u5ba2\u6237\u7aef\u4e0e\u670d\u52a1\u7aef\u5efa\u7acb\u4e00\u4e2a TCP \u8fde\u63a5\u5171\u8ba1\u9700\u8981\u53d1\u9001 3 \u4e2a\u5305\u624d\u80fd\u5b8c\u6210\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u79f0\u4e3a\u4e09\u6b21\u63e1\u624b\uff08Three-way Handshake\uff09\u3002\u5982\u4e0a\u9762\u6240\u8ff0\uff0c\u6570\u636e\u6bb5\u7684\u5e8f\u53f7\u3001\u786e\u8ba4\u5e8f\u53f7\u4ee5\u53ca\u6ed1\u52a8\u7a97\u53e3\u5927\u5c0f\u90fd\u5728\u8fd9\u4e2a\u8fc7\u7a0b\u4e2d\u5b8c\u6210\u3002socket \u7f16\u7a0b\u4e2d\uff0c\u5ba2\u6237\u7aef\u6267\u884c connect() \u65f6\uff0c\u5c06\u89e6\u53d1\u4e09\u6b21\u63e1\u624b\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/strawhatfy.github.io\/2015\/07\/30\/TCP-IP-Protocol\/Three-way_Handshake.png\"><\/p>\n<p>\u6ce8\uff1a<\/p>\n<ol>\n<li>1415531521:1415531521(0) \u8868\u793a\u5206\u7ec4\u7684\u5e8f\u53f7\u662f 1415531521\uff0c\u800c\u62a5\u6587\u7684\u6570\u636e\u5b57\u8282\u6570\u4e3a 0\u3002<\/li>\n<li>WIN:4096 \u8868\u793a\u53d1\u9001\u7aef\u901a\u544a\u7684\u7a97\u53e3\u5927\u5c0f\u4e3a 4096\uff0c\u4e0a\u56fe\u4e2d\u7531\u4e8e\u6ca1\u6709\u4ea4\u6362\u4efb\u4f55\u6570\u636e\u6240\u4ee5\u7a97\u53e3\u7ef4\u6301\u5728 4096\u3002<\/li>\n<li> \u8868\u793a\u7531\u53d1\u7aef\u6307\u660e\u7684\u6700\u5927\u62a5\u6587\u6bb5\u957f\u5ea6\u9009\u9879\u4e3a 1024\u3002<\/li>\n<li>ACK 1415531521 \u8868\u793a\u786e\u8ba4\u5e8f\u53f7\uff0c\u53ea\u5728\u9996\u90e8 ACK \u6807\u5fd7\u4f4d\u8bbe\u7f6e\u4e3a 1 \u65f6\u624d\u6709\u6548\u3002<\/li>\n<\/ol>\n<p>\u5982\u4e0a\u56fe\u6240\u793a\u5b8c\u6210 TCP \u8fde\u63a5\u7684\u5efa\u7acb\uff0c\u5ba2\u6237\u7aef\u4e0e\u670d\u52a1\u7aef\u5171\u8ba1\u53d1\u9001\u4e86 3 \u4e2a\u62a5\u6587\u6bb5\uff1a<\/p>\n<ol>\n<li><strong>\u62a5\u6587\u6bb51\uff1a<\/strong>\u5ba2\u6237\u7aef\u53d1\u9001\u4e00\u4e2a SYN \u62a5\u6587\u6bb5\u6307\u660e\u5ba2\u6237\u6253\u7b97\u8fde\u63a5\u7684\u670d\u52a1\u5668\u7684\u7aef\u53e3\uff0c\u4ee5\u53ca\u521d\u59cb\u5e8f\u53f7\uff08Initial Sequence Number\uff0c\u8fd9\u4e2a\u4f8b\u5b50\u4e2d ISN=1415531521\uff09\u3002<strong>ISN \u7684\u5b9e\u73b0\u76ee\u524d\u4f1a\u968f\u7740\u65f6\u95f4\u7684\u53d8\u5316\u800c\u53d8\u5316\uff0c\u6240\u4ee5\u6bcf\u6b21\u5efa\u7acb\u8fde\u63a5\u65f6\u7684 ISN \u90fd\u4e0d\u540c<\/strong>\uff1b<\/li>\n<li><strong>\u62a5\u6587\u6bb52\uff1a<\/strong>\u670d\u52a1\u5668\u53d1\u56de\u5305\u542b\u670d\u52a1\u5668\u7684\u521d\u59cb\u5e8f\u53f7\u7684 SYN \u62a5\u6587\u6bb5\uff08\u8fd9\u4e2a\u4f8b\u5b50\u4e2d ISN=1823083521\uff09\u4f5c\u4e3a\u5e94\u7b54\u3002\u540c\u65f6\uff0c\u5c06\u786e\u8ba4\u5e8f\u53f7\u8bbe\u7f6e\u4e3a\u5ba2\u6237\u7684 ISN+1 \u4ee5\u62a5\u6587\u6bb51\u8fdb\u884c\u786e\u8ba4\u3002\u4e00\u4e2a SYN \u5c06\u5360\u7528\u4e00\u4e2a\u5e8f\u53f7\uff1b<\/li>\n<li><strong>\u62a5\u6587\u6bb53\uff1a<\/strong>\u5ba2\u6237\u5fc5\u987b\u5c06\u786e\u8ba4\u5e8f\u53f7\u8bbe\u7f6e\u4e3a\u670d\u52a1\u5668\u7684 ISN+1(1823083522) \u4ee5\u5bf9\u670d\u52a1\u5668\u7684 SYN \u62a5\u6587\u6bb5\u8fdb\u884c\u786e\u8ba4\uff1b<\/li>\n<li>\u8fde\u63a5\u5efa\u7acb\uff0c\u5f00\u59cb\u8fdb\u884c\u6570\u636e\u901a\u4fe1\u3002<\/li>\n<\/ol>\n<p>\u4e0a\u9762\u6240\u793a\u7684\u662f\u4e00\u65b9\u4e3b\u52a8\u8fde\u63a5\u53e6\u5916\u4e00\u65b9\u7684\u60c5\u51b5\uff0c\u5b9e\u9645\u4e0a TCP \u4e5f\u5141\u8bb8\u53cc\u65b9\u540c\u65f6\u4e3b\u52a8\u8fde\u63a5\uff0c\u8fd9\u79cd\u60c5\u51b5\u4e0b\u5c31\u8981\u6c42\u8fde\u63a5\u53cc\u65b9\u63d0\u524d\u77e5\u9053\u5bf9\u65b9\u7684\u7aef\u53e3\u3002\u5b9e\u9645\u4e2d\u5f88\u5c11\u51fa\u73b0\u8fd9\u79cd\u9700\u6c42\u3002\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u8981\u53d1\u9001 4 \u4e2a\u62a5\u6587\u6bb5\u624d\u80fd\u5efa\u7acb\u8d77\u8fde\u63a5\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/strawhatfy.github.io\/2015\/07\/30\/TCP-IP-Protocol\/simultaneous_open.png\"><\/p>\n<p><strong>\u9644\uff1aSYN \u6d2a\u6c34\u653b\u51fb<\/strong><\/p>\n<p>\u7531\u4e09\u6b21\u63e1\u624b\u53ef\u4ee5\u770b\u51fa\uff0c\u5f53\u670d\u52a1\u5668\u6536\u5230 SYN \u6570\u636e\u62a5\u6587\u6bb5\u540e\u5c06\u4e3a\u8fde\u63a5\u5206\u914d\u8d44\u6e90\uff0c\u5982\u679c\u670d\u52a1\u5668\u6ca1\u6709\u6536\u5230 ACK \u62a5\u6587\u6bb5\u5c31\u4f1a\u9020\u6210\u534a\u5f00\u8fde\u63a5\uff0c\u6d6a\u8d39\u670d\u52a1\u5668\u8d44\u6e90\u3002SYN \u6d2a\u6c34\u653b\u51fb\u5c31\u662f\u5229\u7528 TCP \u7684\u8fd9\u4e2a\u7f3a\u9677\uff0c\u901a\u8fc7\u5411\u670d\u52a1\u5668\u53d1\u9001\u6d77\u91cf\u7684 SYN \u62a5\u6587\u6bb5\u800c\u8017\u5c3d\u670d\u52a1\u5668\u8d44\u6e90\u3002\u4e00\u822c\u6709\u4e24\u79cd\u65b9\u5f0f\uff1a1\u3001\u5ba2\u6237\u7aef\u6076\u610f\u4e0d\u53d1\u9001 ACK\uff1b2\u3001\u5728\u53d1\u9001\u7ed9\u670d\u52a1\u5668\u7684 SYN \u62a5\u6587\u6bb5\u4e2d\u63d0\u4f9b\u865a\u5047\u7684 IP \u5730\u5740\uff0c\u9020\u6210\u670d\u52a1\u5668\u6c38\u8fdc\u6536\u4e0d\u5230 ACK\u3002<\/p>\n<p>\u8fd9\u79cd\u653b\u51fb\u624b\u6bb5\u5bf9\u4e8e\u73b0\u4ee3\u7f51\u7edc\u6548\u679c\u4e0d\u5927\uff0c\u4f46\u5e76\u4e0d\u80fd\u5b8c\u5168\u9632\u8303\u3002\u4e00\u822c\u8f83\u65b0\u7684 TCP\/IP \u534f\u8bae\u6808\u5b9e\u73b0\u63d0\u90fd\u4f9b\u4e86\u9632\u8303\u624b\u6bb5\uff0c\u4e3b\u8981\u624b\u6bb5\u5305\u62ec SYN cookie \u3001 SynAttackProtect \u4fdd\u62a4\u673a\u5236\u3001\u589e\u52a0\u6700\u5927\u534a\u8fde\u63a5\u3001\u7f29\u77ed\u8d85\u65f6\u65f6\u95f4\u548c\u9650\u5b9a\u67d0\u4e00\u6bb5\u65f6\u95f4\u5185\u6765\u81ea\u540c\u4e00\u6765\u6e90\u8bf7\u6c42\u65b0\u8fde\u63a5\u7684\u6570\u91cf\u7b49\u3002<\/p>\n<p>Linux \u4e0b\u53ef\u4ee5\u901a\u8fc7\u547d\u4ee4\uff1a # netstat -na TCP | grep SYN_RECV | more\uff0c\u6765\u67e5\u770b SYN \u653b\u51fb\u7684\u60c5\u51b5\u3002<\/p>\n<p>\u8fd9\u91cc\u6709\u4e00\u7247\u4e0d\u9519\u7684\u6587\u7ae0\u4ecb\u7ecd\u5982\u4f55\u9632\u5fa1 SYN \u6d2a\u6c34\u653b\u51fb\uff1a<a href=\"http:\/\/tech.uc.cn\/?p=1790\" target=\"_blank\" rel=\"noopener\">TCP\u6d2a\u6c34\u653b\u51fb\uff08SYN Flood\uff09\u7684\u8bca\u65ad\u548c\u5904\u7406<\/a><\/p>\n<h6 id=\"TCP-\u56db\u6b21\u6325\u624b\">TCP \u56db\u6b21\u6325\u624b<\/h6>\n<p>\u5efa\u7acb\u4e00\u4e2a\u8fde\u63a5\u9700\u8981 3 \u6b21\u63e1\u624b\uff0c\u800c\u7ec8\u6b62\u4e00\u4e2a\u8fde\u63a5\u8981\u7ecf\u8fc7 4 \u6b21\u63e1\u624b\u3002\u8fd9\u7531 TCP \u7684\u534a\u5173\u95ed\uff08half-close\uff0c\u8fde\u63a5\u7684\u4e00\u7aef\u5728\u7ed3\u675f\u5b83\u7684\u53d1\u9001\u540e\u8fd8\u80fd\u63a5\u6536\u6765\u81ea\u53e6\u4e00\u7aef\u6570\u636e\u7684\u80fd\u529b\u3002\u5177\u4f53\u7684\u8bf7\u67e5\u9605 TCP \u534a\u5173\u95ed\u7684\u76f8\u5173\u8d44\u6599\uff09\u9020\u6210\u7684\u3002 TCP \u8fde\u63a5\u662f\u5168\u53cc\u5de5\uff0c\u56e0\u6b64\u6bcf\u4e2a\u65b9\u5411\u5fc5\u987b\u5355\u72ec\u5730\u8fdb\u884c\u5173\u95ed\u3002\u4e5f\u5c31\u662f\u5f53\u4e00\u65b9\u5b8c\u6210\u5b83\u7684\u6570\u636e\u53d1\u9001\u4efb\u52a1\u540e\u5c31\u80fd\u53d1\u9001\u4e00\u4e2a FIN \u6765\u7ec8\u6b62\u8fd9\u4e2a\u65b9\u5411\u8fde\u63a5\uff0c\u5f53\u4e00\u7aef\u6536\u5230\u4e00\u4e2a FIN\uff0c\u5b83\u5fc5\u987b\u901a\u77e5\u5e94\u7528\u5c42\u53e6\u4e00\u7aef\u5df2\u7ecf\u7ec8\u6b62\u4e86\u90a3\u4e2a\u65b9\u5411\u7684\u6570\u636e\u4f20\u9001\u3002\u53d1\u9001 FIN 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\u6a21\u5757\u65f6\u6d89\u53ca\u5230\u4e00\u4e9b\u7f51\u7edc\u5f02\u5e38\u7684\u5904\u7406\uff0c\u5728\u6df1\u5165\u4e86\u89e3\u5f02\u5e38\u7684\u5b9a\u4e49\u548c\u5904\u7406\u540e\uff0c [&hellip;]<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,3],"tags":[],"class_list":["post-256","post","type-post","status-publish","format-standard","hentry","category-it","category-network"],"_links":{"self":[{"href":"https:\/\/subk.me\/index.php?rest_route=\/wp\/v2\/posts\/256","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/subk.me\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/subk.me\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/subk.me\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/subk.me\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=256"}],"version-history":[{"count":3,"href":"https:\/\/subk.me\/index.php?rest_route=\/wp\/v2\/posts\/256\/revisions"}],"predecessor-version":[{"id":560,"href":"https:\/\/subk.me\/index.php?rest_route=\/wp\/v2\/posts\/256\/revisions\/560"}],"wp:attachment":[{"href":"https:\/\/subk.me\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=256"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/subk.me\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=256"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/subk.me\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=256"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}