![\"menu-r.4af5f7ec.gif\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/06\/20250601234552-683ce63026493.gif\")
<\/p>\n \u672c\u6587\u8fd8\u6709\u914d\u5957\u7684\u7cbe\u54c1\u8d44\u6e90，\u70b9\u51fb\u83b7\u53d6 <\/p>\n
\u7b80\u4ecb：DNS（\u57df\u540d\u7cfb\u7edf）\u4f5c\u4e3a\u4e92\u8054\u7f51\u57fa\u7840\u670d\u52a1，\u8d1f\u8d23\u57df\u540d\u4e0eIP\u5730\u5740\u8f6c\u6362\u3002DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u5728\u6b64\u8fc7\u7a0b\u4e2d\u8f6c\u53d1\u8bf7\u6c42\u81f3\u9002\u5f53DNS\u670d\u52a1\u5668\u3002\u672c\u5b9e\u9a8c\u4f7f\u7528C\u8bed\u8a00\u7f16\u5199DNS\u4e2d\u7ee7\u670d\u52a1\u5668，\u65e8\u5728\u901a\u8fc7\u5b9e\u8df5\u52a0\u6df1\u5bf9DNS\u5de5\u4f5c\u539f\u7406\u7684\u7406\u89e3\u3002\u5b9e\u9a8c\u5305\u62ec\u7f51\u7edc\u5957\u63a5\u5b57\u7f16\u7a0b\u3001DNS\u62a5\u6587\u89e3\u6790\u3001\u8bf7\u6c42\u8f6c\u53d1\u3001\u54cd\u5e94\u5904\u7406\u53ca\u9519\u8bef\u5904\u7406\u3002\u5b9e\u9a8c\u6587\u6863\u4e2d\u8be6\u7ec6\u63cf\u8ff0\u4e86\u5b9e\u9a8c\u76ee\u7684\u3001\u7406\u8bba\u80cc\u666f\u3001\u8bbe\u8ba1\u601d\u8def\u3001\u5b9e\u73b0\u6b65\u9aa4\u3001\u95ee\u9898\u89e3\u51b3\u65b9\u6cd5\u53ca\u7ed3\u679c\u5206\u6790，\u63d0\u4f9b\u4e86\u6d4b\u8bd5\u7528\u4f8b\u4ee5\u9a8c\u8bc1\u670d\u52a1\u5668\u6027\u80fd\u548c\u9c81\u68d2\u6027\u3002\u6574\u4f53\u4e0a，\u8be5\u5b9e\u9a8c\u5e2e\u52a9\u5b66\u4e60\u8005\u7406\u89e3DNS\u5de5\u4f5c\u673a\u5236，\u63d0\u9ad8\u7f51\u7edc\u7f16\u7a0b\u548c\u95ee\u9898\u5904\u7406\u80fd\u529b\u3002 ![\"DNS\u4e2d\u7ee7\u670d\u52a1\u5668(\u542b\u8be6\u7ec6\u5b9e\u9a8c\u6587\u6863)\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/06\/20250601234552-683ce6302c2df.png\")
<\/p>\n
\u57df\u540d\u7cfb\u7edf（DNS）\u662f\u4e92\u8054\u7f51\u57fa\u7840\u8bbe\u65bd\u7684\u6838\u5fc3\u90e8\u5206，\u8d1f\u8d23\u57df\u540d\u4e0eIP\u5730\u5740\u4e4b\u95f4\u7684\u8f6c\u6362\u3002DNS\u4e2d\u7ee7\u670d\u52a1\u5668，\u4f5c\u4e3a\u57df\u540d\u89e3\u6790\u8fc7\u7a0b\u4e2d\u7684\u4e00\u4e2a\u4e2d\u4ecb，\u5176\u4e3b\u8981\u4f5c\u7528\u5728\u4e8e\u51cf\u8f7b\u6839\u57df\u540d\u670d\u52a1\u5668\u7684\u538b\u529b，\u63d0\u9ad8\u57df\u540d\u89e3\u6790\u7684\u6548\u7387，\u5e76\u80fd\u5728\u5c40\u57df\u7f51\u5185\u5b9e\u73b0\u7f13\u5b58\u89e3\u6790\u7ed3\u679c\u6765\u51cf\u5c11\u5bf9\u5916\u90e8\u7f51\u7edc\u7684\u4f9d\u8d56\u3002 <\/p>\n
\u4e2d\u7ee7\u670d\u52a1\u5668\u4e0d\u4ec5\u54cd\u5e94\u672c\u5730\u7f51\u7edc\u5185\u7684DNS\u8bf7\u6c42，\u800c\u4e14\u53ef\u4ee5\u4e0e\u5176\u4ed6\u4e2d\u7ee7\u670d\u52a1\u5668\u901a\u4fe1，\u5f62\u6210\u4e00\u4e2a\u5c42\u6b21\u5316\u7684\u7f51\u7edc\u7ed3\u6784\u3002\u5f53\u672c\u5730\u4e2d\u7ee7\u670d\u52a1\u5668\u65e0\u6cd5\u89e3\u6790\u67d0\u4e2a\u57df\u540d\u65f6，\u5b83\u4f1a\u5411\u4e0a\u7ea7\u670d\u52a1\u5668\u53d1\u8d77\u8bf7\u6c42，\u83b7\u5f97\u89e3\u6790\u7ed3\u679c\u540e\u518d\u8fd4\u56de\u7ed9\u8bf7\u6c42\u8005\u3002\u8fd9\u6837\u7684\u8bbe\u8ba1\u4e0d\u4ec5\u63d0\u9ad8\u4e86\u57df\u540d\u89e3\u6790\u7684\u901f\u5ea6，\u4e5f\u589e\u5f3a\u4e86\u7f51\u7edc\u7684\u7a33\u5b9a\u6027\u548c\u5b89\u5168\u6027\u3002 <\/p>\n
\u4f7f\u7528DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u53ef\u4ee5\u4e3a\u7f51\u7edc\u7ba1\u7406\u5458\u63d0\u4f9b\u66f4\u591a\u7684\u63a7\u5236\u9009\u9879，\u5982\u7f13\u5b58\u7b56\u7565\u7684\u81ea\u5b9a\u4e49\u3001\u5bf9\u5185\u90e8\u7f51\u7edc\u7684\u67e5\u8be2\u8fdb\u884c\u8fc7\u6ee4\u6216\u91cd\u5b9a\u5411\u7b49\u3002\u6b64\u5916，\u4e2d\u7ee7\u670d\u52a1\u5668\u8fd8\u80fd\u8bb0\u5f55\u67e5\u8be2\u65e5\u5fd7，\u7528\u4e8e\u76d1\u63a7\u548c\u5206\u6790\u7f51\u7edc\u6d41\u91cf，\u4ece\u800c\u4f18\u5316\u7f51\u7edc\u914d\u7f6e\u548c\u6027\u80fd\u3002 <\/p>\n
\u5728\u4e0b\u4e00\u7ae0，\u6211\u4eec\u5c06\u63a2\u8ba8DNS\u67e5\u8be2\u7684\u57fa\u672c\u6d41\u7a0b，\u8fdb\u4e00\u6b65\u7406\u89e3DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u5982\u4f55\u5728\u5176\u4e2d\u53d1\u6325\u4f5c\u7528\u3002 <\/p>\n
\u57df\u540d\u7cfb\u7edf（DNS）\u662f\u4e92\u8054\u7f51\u7684\u57fa\u7840\u8bbe\u65bd\u4e4b\u4e00，\u5176\u4e3b\u8981\u4efb\u52a1\u662f\u5c06\u57df\u540d\u89e3\u6790\u4e3a\u5bf9\u5e94\u7684IP\u5730\u5740\u3002\u8fd9\u4e00\u8fc7\u7a0b\u662f\u900f\u660e\u7684，\u5f53\u7528\u6237\u8f93\u5165\u4e00\u4e2a\u7f51\u5740\u65f6，DNS\u7cfb\u7edf\u4f1a\u5728\u80cc\u540e\u8fdb\u884c\u590d\u6742\u7684\u89e3\u6790\u5de5\u4f5c，\u5c06\u6613\u4e8e\u4eba\u7c7b\u8bb0\u5fc6\u7684\u57df\u540d\u8f6c\u6362\u4e3a\u8ba1\u7b97\u673a\u7406\u89e3\u7684\u6570\u5b57IP\u5730\u5740\u3002 <\/p>\n
\u57df\u540d\u7cfb\u7edf\u7684\u5de5\u4f5c\u673a\u5236\u6d89\u53ca\u5230\u5ba2\u6237\u7aef\u3001DNS\u670d\u52a1\u5668\u4ee5\u53ca\u53ef\u80fd\u5b58\u5728\u7684\u7f13\u5b58\u8282\u70b9\u3002\u6574\u4e2a\u89e3\u6790\u6d41\u7a0b\u9075\u5faa\u4e00\u7cfb\u5217\u6807\u51c6\u5316\u7684\u534f\u8bae\u548c\u6b65\u9aa4，\u5305\u62ec\u9012\u5f52\u67e5\u8be2\u3001\u8fed\u4ee3\u67e5\u8be2\u548c\u7f13\u5b58\u54cd\u5e94\u7b49\u3002\u5f53\u7528\u6237\u53d1\u8d77\u4e00\u4e2aDNS\u67e5\u8be2\u8bf7\u6c42\u65f6，\u8fd9\u4e2a\u8bf7\u6c42\u9996\u5148\u4f1a\u88ab\u53d1\u9001\u5230\u672c\u5730DNS\u89e3\u6790\u5668（\u901a\u5e38\u662f\u7528\u6237\u7684ISP\u63d0\u4f9b\u7684DNS\u670d\u52a1\u5668）\u3002\u5982\u679c\u672c\u5730\u89e3\u6790\u5668\u6ca1\u6709\u7f13\u5b58\u8be5\u57df\u540d\u7684\u8bb0\u5f55，\u5b83\u5c06\u5411\u6839\u57df\u540d\u670d\u52a1\u5668\u67e5\u8be2，\u518d\u4e00\u6b65\u6b65\u5730\u5411\u9876\u7ea7\u57df\u540d\u670d\u52a1\u5668（TLD）\u548c\u6743\u5a01\u57df\u540d\u670d\u52a1\u5668\u8fdb\u884c\u67e5\u8be2，\u6700\u7ec8\u8fd4\u56de\u89e3\u6790\u7ed3\u679c\u7ed9\u7528\u6237\u3002 <\/p>\n
DNS\u67e5\u8be2\u662f\u4e00\u4e2a\u5305\u542b\u591a\u4e2a\u6b65\u9aa4\u7684\u8fc7\u7a0b\u3002\u5b83\u4ece\u7528\u6237\u5c1d\u8bd5\u8bbf\u95ee\u4e00\u4e2a\u7f51\u5740\u5f00\u59cb，\u7136\u540e\u7ecf\u8fc7\u4ee5\u4e0b\u51e0\u4e2a\u5173\u952e\u6b65\u9aa4： <\/p>\n
\u5728\u6574\u4e2a\u67e5\u8be2\u8fc7\u7a0b\u4e2d，\u4e3a\u4e86\u63d0\u9ad8\u6548\u7387\u548c\u54cd\u5e94\u901f\u5ea6，DNS\u7cfb\u7edf\u91c7\u7528\u7f13\u5b58\u673a\u5236，\u51cf\u5c11\u4e86\u5bf9\u57df\u540d\u670d\u52a1\u5668\u7684\u67e5\u8be2\u6b21\u6570\u3002\u540c\u65f6，\u4e3a\u4e86\u9632\u6b62\u5355\u4e00\u8282\u70b9\u7684\u6545\u969c，DNS\u7cfb\u7edf\u8bbe\u8ba1\u4e3a\u5206\u5e03\u5f0f，\u53ef\u4ee5\u627f\u53d7\u5de8\u5927\u7684\u67e5\u8be2\u91cf，\u5e76\u4fdd\u8bc1\u4e86\u9ad8\u53ef\u7528\u6027\u3002 <\/p>\n
DNS\u7f13\u5b58\u662f\u4e00\u79cd\u4f18\u5316\u6280\u672f，\u5b83\u51cf\u5c11\u4e86\u5bf9\u57df\u540d\u89e3\u6790\u7684\u7f51\u7edc\u8bf7\u6c42\u6b21\u6570，\u4ece\u800c\u7f29\u77ed\u4e86\u57df\u540d\u89e3\u6790\u65f6\u95f4\u5e76\u964d\u4f4e\u4e86\u7f51\u7edc\u62e5\u5835\u3002\u7f13\u5b58\u901a\u5e38\u7531\u672c\u5730\u89e3\u6790\u5668\u4ee5\u53ca\u4efb\u4f55\u4e2d\u95f4\u7f51\u7edc\u8bbe\u5907（\u5982\u8def\u7531\u5668\u3001\u9632\u706b\u5899）\u7ef4\u62a4，\u5b83\u4eec\u5728\u6536\u5230DNS\u54cd\u5e94\u540e\u4f1a\u7f13\u5b58\u76f8\u5e94\u7684\u57df\u540d\u4e0eIP\u5730\u5740\u6620\u5c04\u5173\u7cfb\u3002 <\/p>\n
\u7f13\u5b58\u7684\u4f5c\u7528\u8868\u73b0\u5728\u4ee5\u4e0b\u51e0\u4e2a\u65b9\u9762： <\/p>\n
\u7f13\u5b58\u7684\u6548\u7387\u53d6\u51b3\u4e8e\u7f13\u5b58\u7684\u7b56\u7565，\u5305\u62ec\u7f13\u5b58\u7684\u65f6\u9650\u548c\u5237\u65b0\u673a\u5236\u3002\u5f53\u7f13\u5b58\u6570\u636e\u7684\u8fc7\u671f\u65f6\u95f4\u4e34\u8fd1\u65f6，\u53ef\u80fd\u4f1a\u53d1\u8d77\u4e00\u4e2a\u63d0\u524d\u7684\u5237\u65b0\u8bf7\u6c42\u5230\u6743\u5a01\u670d\u52a1\u5668，\u4ee5\u4fdd\u8bc1\u6570\u636e\u7684\u65b0\u9c9c\u5ea6\u3002 <\/p>\n
DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u662f\u4f4d\u4e8e\u672c\u5730\u89e3\u6790\u5668\u548c\u5916\u90e8DNS\u670d\u52a1\u5668\u4e4b\u95f4\u7684\u4e00\u4e2a\u7ec4\u4ef6，\u5b83\u5bf9\u5185\u90e8\u7f51\u7edc\u7684\u67e5\u8be2\u8bf7\u6c42\u8fdb\u884c\u4e2d\u7ee7，\u540c\u65f6\u5bf9\u5916\u90e8\u670d\u52a1\u5668\u7684\u54cd\u5e94\u8fdb\u884c\u5904\u7406\u548c\u4f18\u5316\u3002\u4e2d\u7ee7\u670d\u52a1\u5668\u7684\u4f18\u5316\u7b56\u7565\u4e3b\u8981\u5305\u62ec\u8d1f\u8f7d\u5747\u8861\u3001\u67e5\u8be2\u8fc7\u6ee4\u548c\u54cd\u5e94\u7f13\u5b58\u3002 <\/p>\n
\u4e2d\u7ee7\u670d\u52a1\u5668\u7684\u5b9e\u65bd\u4f18\u5316\u53ef\u4ee5\u663e\u8457\u63d0\u9ad8\u6574\u4e2a\u7f51\u7edc\u7cfb\u7edf\u7684\u6027\u80fd\u548c\u53ef\u9760\u6027\u3002\u901a\u8fc7\u667a\u80fd\u5730\u7ba1\u7406DNS\u67e5\u8be2\u8bf7\u6c42，\u4e2d\u7ee7\u670d\u52a1\u5668\u4f7f\u5f97\u7f51\u7edc\u67b6\u6784\u66f4\u52a0\u7a33\u5065，\u5e76\u63d0\u5347\u4e86\u7528\u6237\u4f53\u9a8c\u3002 <\/p>\n
graph LR
\nA[\u5ba2\u6237\u7aef\u53d1\u8d77\u67e5\u8be2] –>|1.\u89e3\u6790\u5668\u8bf7\u6c42| B[\u672c\u5730\u89e3\u6790\u5668]
\nB –>|2.\u68c0\u67e5\u7f13\u5b58| C[\u7f13\u5b58\u547d\u4e2d?]
\nC –>|\u662f| D[\u8fd4\u56de\u7f13\u5b58\u4e2d\u7684IP]
\nC –>|\u5426| E[\u5916\u90e8DNS\u67e5\u8be2]
\nE –> F[\u6839\u57df\u540d\u670d\u52a1\u5668]
\nF –> G[\u9876\u7ea7\u57df\u540d\u670d\u52a1\u5668]
\nG –> H[\u6743\u5a01\u57df\u540d\u670d\u52a1\u5668]
\nH –> I[\u8fd4\u56deIP\u5730\u5740]
\nI –> J[\u7f13\u5b58IP\u5730\u5740]
\nJ –> K[\u8fd4\u56deIP\u7ed9\u5ba2\u6237\u7aef]<\/p>\n
\u5728\u4e0a\u8ff0\u6d41\u7a0b\u56fe\u4e2d，\u6211\u4eec\u53ef\u4ee5\u770b\u5230DNS\u67e5\u8be2\u548c\u54cd\u5e94\u7f13\u5b58\u7684\u6574\u4e2a\u6d41\u7a0b\u3002\u503c\u5f97\u6ce8\u610f\u7684\u662f，\u968f\u7740\u6280\u672f\u7684\u8fdb\u6b65\u548c\u5b89\u5168\u5a01\u80c1\u7684\u589e\u52a0，DNS\u7cfb\u7edf\u4e5f\u5728\u4e0d\u65ad\u5730\u8fdb\u884c\u4f18\u5316\u548c\u66f4\u65b0，\u4ee5\u5e94\u5bf9\u65e5\u76ca\u590d\u6742\u7684\u7f51\u7edc\u73af\u5883\u3002 <\/p>\n
\u5728\u6df1\u5165\u5b9e\u73b0DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u4e4b\u524d，\u7406\u89e3socket\u7f16\u7a0b\u7684\u57fa\u672c\u539f\u7406\u662f\u81f3\u5173\u91cd\u8981\u7684\u3002Socket\u662f\u8ba1\u7b97\u673a\u7f51\u7edc\u901a\u4fe1\u4e2d\u63d0\u4f9b\u4e00\u4e2a\u7aef\u70b9\u7684\u62bd\u8c61，\u5e94\u7528\u7a0b\u5e8f\u901a\u8fc7\u5b83\u53d1\u9001\u548c\u63a5\u6536\u6d88\u606f\u3002\u5b83\u662f\u7f51\u7edc\u901a\u4fe1\u7684\u57fa\u7840，\u5141\u8bb8\u4e0d\u540c\u7c7b\u578b\u548c\u4f4d\u4e8e\u4e0d\u540c\u4f4d\u7f6e\u7684\u8ba1\u7b97\u673a\u8fdb\u884c\u901a\u4fe1\u3002\u6bcf\u4e00\u5bf9\u901a\u4fe1\u7684\u7aef\u70b9\u90fd\u7531\u4e00\u4e2a\u5957\u63a5\u5b57\u5730\u5740\u6807\u8bc6，\u8be5\u5730\u5740\u7531IP\u5730\u5740\u548c\u7aef\u53e3\u53f7\u7ec4\u6210\u3002 <\/p>\n
\u5957\u63a5\u5b57\u63a5\u53e3(Sockets API)\u4e3a\u7f51\u7edc\u901a\u4fe1\u63d0\u4f9b\u4e86\u6807\u51c6\u5316\u7684\u7cfb\u7edf\u8c03\u7528\u3002\u5bf9\u4e8e\u57fa\u4e8eTCP\/IP\u534f\u8bae\u7684\u7f51\u7edc\u7f16\u7a0b\u6765\u8bf4，\u5e38\u7528\u7684API\u6709 socket() , bind() , connect() , listen() , accept() , send() , recv() \u7b49\u3002\u8fd9\u4e9b\u51fd\u6570\u5141\u8bb8\u7a0b\u5e8f\u5458\u63a7\u5236\u7f51\u7edc\u8fde\u63a5，\u53d1\u9001\u548c\u63a5\u6536\u6570\u636e，\u4ee5\u53ca\u5904\u7406\u7f51\u7edc\u4e8b\u4ef6\u3002 <\/p>\n
C\u8bed\u8a00\u63d0\u4f9b\u4e86\u975e\u5e38\u4e30\u5bcc\u7684\u5e93\u51fd\u6570\u6765\u8fdb\u884c\u7f51\u7edc\u7f16\u7a0b，\u5176\u4e2dPOSIX\u6807\u51c6\u7684socket\u5e93\u662f\u6700\u5e38\u7528\u7684\u3002C\u8bed\u8a00\u4e4b\u6240\u4ee5\u5728\u7cfb\u7edf\u7f16\u7a0b，\u5c24\u5176\u662f\u5728\u7f51\u7edc\u7f16\u7a0b\u9886\u57df\u5e94\u7528\u5e7f\u6cdb，\u662f\u56e0\u4e3a\u5b83\u63d0\u4f9b\u4e86\u4f4e\u7ea7\u522b\u7684\u5185\u5b58\u7ba1\u7406\u548c\u786c\u4ef6\u63a7\u5236\u80fd\u529b\u3002\u8fd9\u610f\u5473\u7740\u5728C\u8bed\u8a00\u4e2d\u53ef\u4ee5\u7cbe\u786e\u5730\u63a7\u5236\u7f51\u7edc\u534f\u8bae\u6808\u7684\u7ec6\u8282，\u4f46\u4e5f\u9700\u8981\u7a0b\u5e8f\u5458\u5bf9\u7ec6\u8282\u6709\u6df1\u523b\u7684\u7406\u89e3\u3002 <\/p>\n
\/\/ \u793a\u4f8b\u4ee3\u7801：\u521b\u5efa\u4e00\u4e2aTCP socket\u5e76\u7ed1\u5b9a\u5230\u672c\u5730\u7aef\u53e3
\n#include <stdio.h>
\n#include <stdlib.h>
\n#include <string.h>
\n#include <unistd.h>
\n#include <arpa\/inet.h><\/p>\n
int main() {
\n int sock;
\n struct sockaddr_in servaddr;<\/p>\n
\/\/ \u521b\u5efasocket
\n sock = socket(PF_INET, SOCK_STREAM, 0);
\n if (sock == -1) {
\n perror("socket() error");
\n exit(1);
\n }<\/p>\n
\/\/ \u8bbe\u7f6e\u670d\u52a1\u5668\u5730\u5740
\n memset(&servaddr, 0, sizeof(servaddr));
\n servaddr.sin_family = AF_INET;
\n servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
\n servaddr.sin_port = htons(12345); \/\/ \u7ed1\u5b9a\u7aef\u53e3<\/p>\n
\/\/ \u7ed1\u5b9asocket\u5230\u5730\u5740
\n if (bind(sock, (struct sockaddr*)&servaddr, sizeof(servaddr)) == -1) {
\n perror("bind() error");
\n close(sock);
\n exit(1);
\n }<\/p>\n
\/\/ \u7ee7\u7eed\u540e\u7eed\u7684\u76d1\u542c(listen)\u548c\u63a5\u53d7(accept)\u64cd\u4f5c…
\n}<\/p>\n
\u5728\u4e0a\u8ff0\u793a\u4f8b\u4e2d，\u6211\u4eec\u9996\u5148\u521b\u5efa\u4e86\u4e00\u4e2aTCP socket，\u7136\u540e\u4e3a\u5176\u6307\u5b9a\u4e86\u4e00\u4e2a\u5730\u5740\u7ed3\u6784\u4f53，\u6307\u5b9a\u4e86IP\u7248\u672c\u3001IP\u5730\u5740\u3001\u7aef\u53e3\u53f7\u7b49\u4fe1\u606f\u3002\u4e4b\u540e，\u6211\u4eec\u8c03\u7528 bind() \u51fd\u6570\u5c06socket\u7ed1\u5b9a\u5230\u6307\u5b9a\u7684\u5730\u5740\u4e0a\u3002\u8fd9\u91cc\u53ea\u662f\u7a0b\u5e8f\u7684\u4e00\u4e2a\u5f00\u59cb，\u540e\u7eed\u8fd8\u9700\u8981\u76d1\u542c\u8fde\u63a5\u8bf7\u6c42，\u63a5\u53d7\u8fde\u63a5，\u5e76\u8fdb\u884c\u6570\u636e\u7684\u53d1\u9001\u548c\u63a5\u6536\u5904\u7406\u3002 <\/p>\n
C\u8bed\u8a00\u7f51\u7edc\u7f16\u7a0b\u7684\u76ee\u6807\u4e0d\u4ec5\u662f\u5b66\u4e60\u5982\u4f55\u4f7f\u7528\u8fd9\u4e9b\u51fd\u6570，\u66f4\u91cd\u8981\u7684\u662f\u7406\u89e3\u7f51\u7edc\u534f\u8bae\u6808\u7684\u884c\u4e3a\u548cTCP\/IP\u901a\u4fe1\u6a21\u578b\u7684\u5de5\u4f5c\u65b9\u5f0f\u3002\u7406\u89e3\u4e86\u8fd9\u4e9b\u57fa\u672c\u539f\u7406\u4e4b\u540e，\u6211\u4eec\u5c31\u53ef\u4ee5\u5f00\u59cb\u8bbe\u8ba1DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u7684\u67b6\u6784\u548c\u5de5\u4f5c\u6d41\u7a0b\u3002 <\/p>\n
\u4e00\u4e2aDNS\u4e2d\u7ee7\u670d\u52a1\u5668\u7684\u4e3b\u8981\u529f\u80fd\u6a21\u5757\u901a\u5e38\u5305\u62ec\u4ee5\u4e0b\u90e8\u5206： <\/p>\n
\u8fd9\u4e9b\u6a21\u5757\u7684\u5b9e\u73b0\u903b\u8f91\u8981\u5f7c\u6b64\u72ec\u7acb，\u4fbf\u4e8e\u7ef4\u62a4\u548c\u5347\u7ea7\u3002\u4f8b\u5982，DNS\u67e5\u8be2\u5904\u7406\u6a21\u5757\u4f1a\u5173\u6ce8\u4e8e\u89e3\u6790\u8bf7\u6c42\u3001\u6784\u9020\u8f6c\u53d1\u8bf7\u6c42\u548c\u6784\u9020\u8fd4\u56de\u54cd\u5e94\u3002\u8f6c\u53d1\u6a21\u5757\u4f1a\u5173\u6ce8\u4e8e\u5982\u4f55\u9ad8\u6548\u5730\u5c06\u8bf7\u6c42\u8f6c\u53d1\u7ed9\u4e0a\u6e38\u670d\u52a1\u5668\u3002\u7f13\u5b58\u7ba1\u7406\u6a21\u5757\u5219\u4e13\u6ce8\u4e8e\u5982\u4f55\u5b58\u50a8\u548c\u68c0\u7d22\u7f13\u5b58\u9879\u3002 <\/p>\n
\u4e3a\u4e86\u5b9e\u73b0\u8fd9\u4e9b\u6a21\u5757，\u6211\u4eec\u9700\u8981\u5b9a\u4e49\u6570\u636e\u7ed3\u6784\u6765\u4fdd\u5b58\u5ba2\u6237\u7aef\u8fde\u63a5\u7684\u72b6\u6001\u3001\u7f13\u5b58\u9879\u4ee5\u53ca\u8f6c\u53d1\u8bf7\u6c42\u7684\u4fe1\u606f\u3002\u8fd9\u4e9b\u6570\u636e\u7ed3\u6784\u53ef\u80fd\u662f： <\/p>\n
\u5173\u952e\u6570\u636e\u7ed3\u6784\u7684\u8bbe\u8ba1\u5bf9\u4e2d\u7ee7\u670d\u52a1\u5668\u7684\u6027\u80fd\u6709\u7740\u76f4\u63a5\u5f71\u54cd\u3002\u5408\u7406\u7684\u8bbe\u8ba1\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8be2\u5904\u7406\u901f\u5ea6\u3001\u51cf\u5c11\u5185\u5b58\u6d88\u8017\u4ee5\u53ca\u63d0\u5347\u7f13\u5b58\u7684\u6548\u7387\u3002 <\/p>\n
\u4e00\u4e2a\u793a\u4f8b\u6027\u7684\u6570\u636e\u7ed3\u6784\u53ef\u80fd\u5982\u4e0b： <\/p>\n
\/\/ DNS\u8bf7\u6c42\u8bb0\u5f55\u7ed3\u6784\u4f53
\ntypedef struct dns_request {
\n char domain_name[256]; \/\/ \u57df\u540d
\n int dns_type; \/\/ DNS\u8bb0\u5f55\u7c7b\u578b
\n time_t expire_time; \/\/ \u7f13\u5b58\u8fc7\u671f\u65f6\u95f4
\n \/\/ … \u5176\u4ed6\u76f8\u5173\u5b57\u6bb5
\n} DNSRequest;<\/p>\n
\/\/ \u7f13\u5b58\u9879\u7ed3\u6784\u4f53
\ntypedef struct cache_entry {
\n DNSRequest request; \/\/ DNS\u8bf7\u6c42
\n char* resource_data; \/\/ \u8d44\u6e90\u8bb0\u5f55\u6570\u636e
\n size_t data_size; \/\/ \u8d44\u6e90\u8bb0\u5f55\u6570\u636e\u5927\u5c0f
\n \/\/ … \u5176\u4ed6\u76f8\u5173\u5b57\u6bb5
\n} CacheEntry;<\/p>\n
\/\/ \u670d\u52a1\u5668\u72b6\u6001\u7ed3\u6784\u4f53
\ntypedef struct server_state {
\n DNSRequest* cache; \/\/ \u7f13\u5b58
\n size_t cache_size; \/\/ \u7f13\u5b58\u5927\u5c0f
\n size_t cache_count; \/\/ \u7f13\u5b58\u9879\u6570\u91cf
\n \/\/ … \u5176\u4ed6\u670d\u52a1\u5668\u72b6\u6001\u4fe1\u606f
\n} ServerState;<\/p>\n
\u5728\u5b9e\u73b0\u7b97\u6cd5\u65b9\u9762，\u4f8b\u5982\u67e5\u8be2\u5904\u7406\u6a21\u5757\u4e2d，\u9700\u8981\u5bf9DNS\u67e5\u8be2\u8bf7\u6c42\u8fdb\u884c\u89e3\u6790，\u8fd9\u53ef\u80fd\u9700\u8981\u5b9e\u73b0DNS\u62a5\u6587\u89e3\u6790\u7684\u7b97\u6cd5，\u4ee5\u53ca\u5982\u4f55\u6839\u636e\u89e3\u6790\u7ed3\u679c\u6784\u9020\u65b0\u7684\u67e5\u8be2\u8bf7\u6c42\u3002\u8f6c\u53d1\u6a21\u5757\u53ef\u80fd\u6d89\u53ca\u7b97\u6cd5\u6765\u9009\u62e9\u6700\u4f18\u7684\u4e0a\u6e38DNS\u670d\u52a1\u5668\u8fdb\u884c\u67e5\u8be2，\u4f8b\u5982\u4f7f\u7528\u8f6e\u8be2\u3001\u6700\u5c11\u8fde\u63a5\u6216\u54cd\u5e94\u65f6\u95f4\u6700\u77ed\u7684\u7b56\u7565\u6765\u51b3\u5b9a\u5411\u54ea\u4e2a\u670d\u52a1\u5668\u8f6c\u53d1\u3002 <\/p>\n
\/\/ \u793a\u4f8b：\u9009\u62e9\u4e00\u4e2a\u4e0a\u6e38DNS\u670d\u52a1\u5668\u8fdb\u884c\u8f6c\u53d1
\nint select_upstream_server(ServerState* state) {
\n \/\/ \u4f7f\u7528\u7b80\u5355\u7684\u8f6e\u8be2\u7b56\u7565\u9009\u62e9\u670d\u52a1\u5668
\n static int last_selected = -1;
\n int count = sizeof(state->upstream_servers) \/ sizeof(state->upstream_servers[0]);
\n if (last_selected < 0) {
\n last_selected = 0;
\n } else {
\n last_selected++;
\n if (last_selected >= count) {
\n last_selected = 0;
\n }
\n }
\n return last_selected;
\n}<\/p>\n
\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\u5b9e\u73b0\u4e86\u4e00\u4e2a\u7b80\u5355\u7684\u8f6e\u8be2\u7b97\u6cd5，\u8fd9\u4e2a\u7b97\u6cd5\u4f1a\u4f9d\u6b21\u904d\u5386\u4e0a\u6e38\u670d\u52a1\u5668\u5217\u8868\u5e76\u8fd4\u56de\u4e00\u4e2a\u7d22\u5f15\u3002\u5b9e\u9645\u5e94\u7528\u4e2d，\u7b97\u6cd5\u53ef\u80fd\u4f1a\u66f4\u52a0\u590d\u6742，\u6bd4\u5982\u4f1a\u8003\u8651\u670d\u52a1\u5668\u7684\u8d1f\u8f7d\u60c5\u51b5\u548c\u5386\u53f2\u54cd\u5e94\u65f6\u95f4\u3002 <\/p>\n
\u5b9e\u73b0DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u7684\u5404\u4e2a\u6a21\u5757\u548c\u7b97\u6cd5\u9700\u8981\u5bf9C\u8bed\u8a00\u548c\u7f51\u7edc\u7f16\u7a0b\u6709\u6df1\u5165\u7684\u7406\u89e3，\u540c\u65f6\u4e5f\u9700\u8981\u5bf9DNS\u534f\u8bae\u6709\u5f88\u597d\u7684\u638c\u63e1\u3002\u4e0b\u4e00\u8282\u6211\u4eec\u5c06\u8be6\u7ec6\u4ecb\u7ecdDNS\u62a5\u6587\u89e3\u6790\u65b9\u6cd5，\u8fd9\u5bf9\u4e8e\u5b9e\u73b0DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u662f\u6838\u5fc3\u90e8\u5206\u4e4b\u4e00\u3002 <\/p>\n
\u5728\u73b0\u4ee3\u7684\u7f51\u7edc\u901a\u4fe1\u4e2d，\u5957\u63a5\u5b57\u7f16\u7a0b（Socket Programming）\u662f\u6784\u5efa\u7f51\u7edc\u5e94\u7528\u7a0b\u5e8f\u7684\u57fa\u7840\u3002\u65e0\u8bba\u662f\u5ba2\u6237\u7aef\u8fd8\u662f\u670d\u52a1\u5668\u7aef，\u7f51\u7edc\u7f16\u7a0b\u90fd\u6d89\u53ca\u5957\u63a5\u5b57\u7684\u521b\u5efa\u3001\u914d\u7f6e\u3001\u7ed1\u5b9a\u3001\u76d1\u542c\u3001\u8fde\u63a5\u3001\u63a5\u6536\u3001\u53d1\u9001\u7b49\u64cd\u4f5c\u3002\u5728\u672c\u7ae0\u8282\u4e2d，\u6211\u4eec\u5c06\u6df1\u5165\u63a2\u8ba8TCP\/IP\u534f\u8bae\u6808\u7684\u57fa\u672c\u77e5\u8bc6，\u4ee5\u53ca\u5982\u4f55\u5728C\u8bed\u8a00\u73af\u5883\u4e0b\u5229\u7528\u5957\u63a5\u5b57API\u5b9e\u73b0\u7f51\u7edc\u901a\u4fe1，\u5e76\u5206\u6790\u5728\u7f51\u7edc\u901a\u4fe1\u4e2d\u53ef\u80fd\u9047\u5230\u7684\u5f02\u5e38\u5904\u7406\u3002 <\/p>\n
Internet\u534f\u8bae（IP）\u662f\u4e92\u8054\u7f51\u7684\u6838\u5fc3\u534f\u8bae\u4e4b\u4e00，\u5b83\u89c4\u5b9a\u4e86\u4e92\u8054\u7f51\u4e0a\u6570\u636e\u5305\u7684\u683c\u5f0f\u548c\u8f6c\u53d1\u65b9\u5f0f\u3002IP\u534f\u8bae\u786e\u4fdd\u6570\u636e\u5305\u80fd\u591f\u4ece\u6e90\u4e3b\u673a\u4f20\u8f93\u5230\u76ee\u7684\u4e3b\u673a，\u4f46\u4e0d\u4fdd\u8bc1\u4f20\u8f93\u7684\u53ef\u9760\u6027\u548c\u987a\u5e8f，\u8fd9\u7531\u4e0a\u5c42\u7684\u4f20\u8f93\u5c42\u534f\u8bae\u5982TCP\u6765\u5b9e\u73b0\u3002 <\/p>\n
IP\u534f\u8bae\u6709\u591a\u4e2a\u7248\u672c，\u5305\u62ecIPv4\u548cIPv6\u3002IPv4\u662f\u76ee\u524d\u5e7f\u6cdb\u4f7f\u7528\u7684\u7248\u672c，\u4f46\u968f\u7740\u4e92\u8054\u7f51\u7684\u53d1\u5c55，\u5730\u5740\u7a7a\u95f4\u7684\u4e0d\u8db3\u5bfc\u81f4\u4e86IPv6\u7684\u51fa\u73b0，\u5176\u62e5\u6709\u66f4\u5927\u7684\u5730\u5740\u7a7a\u95f4\u548c\u6539\u8fdb\u7684\u7279\u6027\u3002 <\/p>\n
\u4f20\u8f93\u63a7\u5236\u534f\u8bae（TCP）\u662f\u4e00\u4e2a\u9762\u5411\u8fde\u63a5\u7684\u534f\u8bae，\u5b83\u63d0\u4f9b\u4e86\u53ef\u9760\u7684\u3001\u6709\u5e8f\u7684\u5b57\u8282\u6d41\u4f20\u8f93，\u9002\u5408\u4e8e\u6587\u4ef6\u4f20\u8f93\u3001\u90ae\u4ef6\u53d1\u9001\u7b49\u9700\u8981\u9ad8\u53ef\u9760\u6027\u7684\u5e94\u7528\u3002\u7528\u6237\u6570\u636e\u62a5\u534f\u8bae（UDP）\u662f\u4e00\u4e2a\u65e0\u8fde\u63a5\u7684\u534f\u8bae，\u4f20\u8f93\u901f\u5ea6\u5feb\u4f46\u4e0d\u4fdd\u8bc1\u6570\u636e\u7684\u5b8c\u6574\u6027，\u9002\u7528\u4e8e\u5bf9\u5b9e\u65f6\u6027\u8981\u6c42\u9ad8\u7684\u5e94\u7528，\u5982\u5728\u7ebf\u89c6\u9891\u548c\u6e38\u620f\u3002 <\/p>\n
\u5728C\u8bed\u8a00\u4e2d，\u5957\u63a5\u5b57API\u4f7f\u7528\u4e00\u7cfb\u5217\u7684\u51fd\u6570\u8fdb\u884c\u7f51\u7edc\u7f16\u7a0b，\u5176\u4e2d\u5173\u952e\u7684\u51fd\u6570\u5305\u62ec socket() , bind() , listen() , accept() , connect() , send() , recv() \u7b49\u3002 <\/p>\n
\u4e0b\u9762\u662f\u4e00\u4e2a\u7b80\u5355\u7684TCP\u670d\u52a1\u5668\u7aef\u548c\u5ba2\u6237\u7aef\u5957\u63a5\u5b57\u7f16\u7a0b\u793a\u4f8b\u4ee3\u7801： <\/p>\n
#include <stdio.h>
\n#include <stdlib.h>
\n#include <string.h>
\n#include <unistd.h>
\n#include <sys\/types.h>
\n#include <sys\/socket.h>
\n#include <netinet\/in.h><\/p>\n
#define PORT 8080
\n#define BUFSIZE 256<\/p>\n
int main(int argc, char *argv[]) {
\n int sockfd, newsockfd;
\n struct sockaddr_in server_addr, client_addr;
\n socklen_t client_len;
\n char buffer[BUFSIZE];<\/p>\n
\/\/ \u521b\u5efa\u5957\u63a5\u5b57
\n sockfd = socket(AF_INET, SOCK_STREAM, 0);<\/p>\n
\/\/ \u521d\u59cb\u5316\u5730\u5740\u7ed3\u6784\u4f53
\n memset(&server_addr, 0, sizeof(server_addr));
\n server_addr.sin_family = AF_INET;
\n server_addr.sin_addr.s_addr = INADDR_ANY;
\n server_addr.sin_port = htons(PORT);<\/p>\n
\/\/ \u7ed1\u5b9a\u5957\u63a5\u5b57
\n bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr));<\/p>\n
\/\/ \u76d1\u542c\u8fde\u63a5
\n listen(sockfd, 5);<\/p>\n
client_len = sizeof(client_addr);
\n \/\/ \u63a5\u53d7\u8fde\u63a5
\n newsockfd = accept(sockfd, (struct sockaddr *)&client_addr, &client_len);<\/p>\n
\/\/ \u8bfb\u53d6\u6570\u636e
\n int bytes_read = recv(newsockfd, buffer, BUFSIZE – 1, 0);
\n buffer[bytes_read] = '\\\\0';
\n printf("Client says: %s\\\\n", buffer);<\/p>\n
\/\/ \u53d1\u9001\u6570\u636e
\n const char *message = "Server received your message!";
\n send(newsockfd, message, strlen(message), 0);<\/p>\n
\/\/ \u5173\u95ed\u5957\u63a5\u5b57
\n close(newsockfd);
\n close(sockfd);
\n return 0;
\n}<\/p>\n
\u5728\u8fd9\u4e2aTCP\u670d\u52a1\u5668\u793a\u4f8b\u4e2d，\u670d\u52a1\u5668\u521b\u5efa\u4e86\u4e00\u4e2a\u5957\u63a5\u5b57，\u5e76\u7ed1\u5b9a\u5230\u7aef\u53e38080\u4e0a，\u7136\u540e\u5f00\u59cb\u76d1\u542c\u8fde\u63a5\u3002\u4e00\u65e6\u5ba2\u6237\u7aef\u53d1\u8d77\u8fde\u63a5\u8bf7\u6c42\u5e76\u88ab\u63a5\u53d7，\u670d\u52a1\u5668\u5c31\u53ef\u4ee5\u63a5\u6536\u6765\u81ea\u5ba2\u6237\u7aef\u7684\u6570\u636e\u5e76\u53d1\u9001\u56de\u590d\u3002 <\/p>\n
\u5728\u8fdb\u884c\u7f51\u7edc\u7f16\u7a0b\u65f6，\u9700\u8981\u5904\u7406\u591a\u79cd\u7f51\u7edc\u5f02\u5e38，\u8fd9\u4e9b\u5f02\u5e38\u53ef\u80fd\u5bfc\u81f4\u7a0b\u5e8f\u7684\u884c\u4e3a\u4e0d\u6b63\u5e38\u751a\u81f3\u5d29\u6e83\u3002\u5e38\u89c1\u7684\u7f51\u7edc\u5f02\u5e38\u5305\u62ec\u4f46\u4e0d\u9650\u4e8e： <\/p>\n
\u5728C\u8bed\u8a00\u4e2d，\u53ef\u4ee5\u901a\u8fc7\u68c0\u67e5\u5957\u63a5\u5b57API\u8c03\u7528\u7684\u8fd4\u56de\u503c\u6765\u68c0\u6d4b\u5f02\u5e38\u60c5\u51b5\u3002\u901a\u5e38，\u8fd9\u4e9bAPI\u5728\u9047\u5230\u9519\u8bef\u65f6\u4f1a\u8fd4\u56de-1，\u5e76\u8bbe\u7f6e\u5168\u5c40\u53d8\u91cf errno \u4e3a\u76f8\u5e94\u7684\u9519\u8bef\u7801\u3002 <\/p>\n
\u4e3a\u4e86\u5904\u7406\u8fd9\u4e9b\u5f02\u5e38，\u9700\u8981\u7f16\u5199\u9519\u8bef\u68c0\u6d4b\u548c\u5904\u7406\u4ee3\u7801\u5757，\u4f8b\u5982： <\/p>\n
if (listen(sockfd, 5) == -1) {
\n perror("Listen failed");
\n close(sockfd);
\n exit(1);
\n}<\/p>\n
\u8fd9\u6bb5\u4ee3\u7801\u5728\u8c03\u7528 listen() \u51fd\u6570\u540e\u68c0\u67e5\u8fd4\u56de\u503c\u3002\u5982\u679c listen() \u5931\u8d25，\u7a0b\u5e8f\u5c06\u6253\u5370\u9519\u8bef\u6d88\u606f，\u5e76\u9000\u51fa\u6267\u884c\u3002\u8fd9\u662f\u5f02\u5e38\u5904\u7406\u7684\u4e00\u4e2a\u57fa\u672c\u793a\u4f8b，\u5b9e\u9645\u5e94\u7528\u4e2d\u53ef\u80fd\u9700\u8981\u66f4\u590d\u6742\u7684\u903b\u8f91，\u5305\u62ec\u9519\u8bef\u65e5\u5fd7\u8bb0\u5f55\u3001\u91cd\u8bd5\u673a\u5236\u548c\u7a0b\u5e8f\u6062\u590d\u7b56\u7565\u3002 <\/p>\n
\u7f51\u7edc\u5957\u63a5\u5b57\u7f16\u7a0b\u662f\u7f51\u7edc\u5e94\u7528\u5f00\u53d1\u4e2d\u4e0d\u53ef\u6216\u7f3a\u7684\u90e8\u5206，\u5b83\u4f7f\u5f00\u53d1\u8005\u80fd\u591f\u5b9e\u73b0\u7f51\u7edc\u901a\u4fe1\u548c\u6570\u636e\u4ea4\u6362\u3002\u5728\u672c\u7ae0\u4e2d，\u6211\u4eec\u4e86\u89e3\u4e86TCP\/IP\u534f\u8bae\u6808\u7684\u57fa\u7840，\u63a2\u8ba8\u4e86\u5957\u63a5\u5b57\u7f16\u7a0b\u7684\u5b9e\u8df5，\u4ee5\u53ca\u5982\u4f55\u5904\u7406\u7f51\u7edc\u901a\u4fe1\u4e2d\u53ef\u80fd\u51fa\u73b0\u7684\u5f02\u5e38\u60c5\u51b5\u3002\u901a\u8fc7\u5bf9\u8fd9\u4e9b\u6982\u5ff5\u548c\u6280\u5de7\u7684\u638c\u63e1，\u5f00\u53d1\u8005\u53ef\u4ee5\u6784\u5efa\u51fa\u7a33\u5b9a\u4e14\u9ad8\u6548\u7684\u7f51\u7edc\u5e94\u7528\u7a0b\u5e8f\u3002 <\/p>\n
DNS\u62a5\u6587，\u6216\u79f0DNS\u6d88\u606f，\u662fDNS\u534f\u8bae\u4e2d\u7528\u4e8e\u4ea4\u6362\u6570\u636e\u7684\u57fa\u672c\u6570\u636e\u5355\u4f4d\u3002\u5b83\u901a\u8fc7UDP\u6216TCP\u4f20\u8f93，\u6700\u5e38\u89c1\u7684\u7aef\u53e3\u53f7\u4e3a53\u3002DNS\u62a5\u6587\u4e3b\u8981\u5305\u542b\u4ee5\u4e0b\u51e0\u4e2a\u90e8\u5206： <\/p>\n
\u62a5\u6587\u5934\u670912\u5b57\u8282\u957f，\u5176\u540e\u8ddf\u7740\u56db\u4e2a\u533a\u57df，\u5404\u533a\u57df\u5305\u542b\u82e5\u5e72\u8d44\u6e90\u8bb0\u5f55（RR）\u3002\u6bcf\u6761\u8d44\u6e90\u8bb0\u5f55\u7531\u4ee5\u4e0b\u5b57\u6bb5\u7ec4\u6210：\u540d\u79f0（Name）\u3001\u7c7b\u578b（Type）\u3001\u7c7b\u522b（Class）\u3001\u751f\u5b58\u65f6\u95f4（TTL）\u3001\u8d44\u6e90\u6570\u636e\u957f\u5ea6（RDLength）\u548c\u8d44\u6e90\u6570\u636e（RDATA）\u3002\u8fd9\u4e9b\u8d44\u6e90\u8bb0\u5f55\u53ef\u4ee5\u662f\u67e5\u8be2\u95ee\u9898\u7684\u76f8\u5173\u4fe1\u606f（\u5728\u95ee\u9898\u533a\u57df\u4e2d），\u4e5f\u53ef\u4ee5\u662f\u5bf9\u67e5\u8be2\u7684\u54cd\u5e94（\u5728\u56de\u7b54\u3001\u6743\u5a01\u6216\u9644\u52a0\u533a\u57df\u4e2d）\u3002 <\/p>\n
RCODE：\u54cd\u5e94\u4ee3\u7801，\u8868\u793a\u54cd\u5e94\u7684\u72b6\u6001\u3002 <\/p>\n<\/li>\n
\u95ee\u9898\u533a\u57df ：\u5305\u542b\u67e5\u8be2\u7684\u57df\u540d\u3001\u67e5\u8be2\u7c7b\u578b\u3001\u67e5\u8be2\u7c7b\u522b\u7684\u4fe1\u606f\u3002\u5728DNS\u67e5\u8be2\u8fc7\u7a0b\u4e2d，\u53ea\u6709\u95ee\u9898\u533a\u57df\u662f\u5fc5\u987b\u7684\u3002 <\/p>\n<\/li>\n
\u56de\u7b54\u533a\u57df\u3001\u6743\u5a01\u533a\u57df\u548c\u9644\u52a0\u4fe1\u606f\u533a\u57df ：\u8fd9\u4e9b\u533a\u57df\u90fd\u7531\u8d44\u6e90\u8bb0\u5f55\u6784\u6210，\u5305\u542b\u57df\u540d\u3001\u8bb0\u5f55\u7c7b\u578b\u3001TTL\u548c\u8d44\u6e90\u6570\u636e\u3002TTL\u8868\u793a\u8be5\u8bb0\u5f55\u5728\u7f13\u5b58\u4e2d\u5e94\u4fdd\u6301\u7684\u65f6\u95f4\u3002 <\/p>\n<\/li>\n<\/ul>\n
\u5728\u89e3\u6790DNS\u62a5\u6587\u65f6，\u9996\u5148\u68c0\u67e5\u62a5\u6587\u5934\u4e2d\u7684\u6807\u5fd7\u4f4d\u548c\u8ba1\u6570\u5668，\u4ee5\u786e\u5b9a\u6d88\u606f\u7684\u7c7b\u578b\u548c\u533a\u57df\u8ba1\u6570\u3002\u4e4b\u540e\u5bf9\u5404\u4e2a\u533a\u57df\u4e2d\u7684\u8d44\u6e90\u8bb0\u5f55\u8fdb\u884c\u89e3\u6790，\u63d0\u53d6\u57df\u540d\u548c\u76f8\u5173\u7684IP\u5730\u5740\u6216\u5176\u4ed6\u6570\u636e\u3002 <\/p>\n
\u4e0b\u9762\u662f\u4e00\u4e2a\u4f7f\u7528C\u8bed\u8a00\u89e3\u6790DNS\u62a5\u6587\u5934\u90e8\u7684\u793a\u4f8b\u4ee3\u7801： <\/p>\n
#include <stdio.h>
\n#include <stdint.h><\/p>\n
\/\/ DNS\u62a5\u6587\u5934\u90e8\u7ed3\u6784\u5b9a\u4e49
\ntypedef struct {
\n uint16_t id; \/\/ \u6807\u8bc6\u7b26
\n uint16_t flags; \/\/ \u6807\u5fd7
\n uint16_t qdcount; \/\/ \u95ee\u9898\u8ba1\u6570
\n uint16_t ancount; \/\/ \u7b54\u6848\u8ba1\u6570
\n uint16_t nscount; \/\/ \u6743\u5a01\u8ba1\u6570
\n uint16_t arcount; \/\/ \u9644\u52a0\u8bb0\u5f55\u8ba1\u6570
\n} DNSHeader;<\/p>\n
\/\/ \u4ece\u7f51\u7edc\u5b57\u8282\u5e8f\u8f6c\u6362\u5230\u4e3b\u673a\u5b57\u8282\u5e8f
\nvoid dns_header_unswap(DNSHeader* header) {
\n header->id = ntohs(header->id);
\n header->flags = ntohs(header->flags);
\n header->qdcount = ntohs(header->qdcount);
\n header->ancount = ntohs(header->ancount);
\n header->nscount = ntohs(header->nscount);
\n header->arcount = ntohs(header->arcount);
\n}<\/p>\n
int main() {
\n \/\/ \u5047\u8bbednsPacket\u662f\u5df2\u7ecf\u63a5\u6536\u7684DNS\u62a5\u6587\u7684\u539f\u59cb\u6570\u636e
\n unsigned char dnsPacket[] = {\/* … *\/};
\n DNSHeader header;
\n \/\/ \u5c06\u7f51\u7edc\u5b57\u8282\u5e8f\u7684DNS\u62a5\u6587\u5934\u90e8\u590d\u5236\u5230\u7ed3\u6784\u4f53\u4e2d
\n memcpy(&header, dnsPacket, sizeof(DNSHeader));
\n \/\/ \u8f6c\u6362\u4e3a\u672c\u5730\u5b57\u8282\u5e8f
\n dns_header_unswap(&header);
\n \/\/ \u6253\u5370\u62a5\u6587\u5934\u90e8\u4fe1\u606f
\n printf("ID: %u\\\\n", header.id);
\n printf("QR: %u\\\\n", (header.flags & 0x8000) >> 15);
\n printf("OPCODE: %u\\\\n", (header.flags & 0x7800) >> 11);
\n printf("AA: %u\\\\n", (header.flags & 0x0400) >> 10);
\n printf("TC: %u\\\\n", (header.flags & 0x0200) >> 9);
\n printf("RD: %u\\\\n", (header.flags & 0x0100) >> 8);
\n printf("RA: %u\\\\n", (header.flags & 0x0080) >> 7);
\n printf("Z: %u\\\\n", (header.flags & 0x0070) >> 4);
\n printf("RCODE: %u\\\\n", header.flags & 0x000f);
\n printf("QDCOUNT: %u\\\\n", header.qdcount);
\n printf("ANCOUNT: %u\\\\n", header.ancount);
\n printf("NSCOUNT: %u\\\\n", header.nscount);
\n printf("ARCOUNT: %u\\\\n", header.arcount);
\n return 0;
\n}<\/p>\n
\u5728\u6b64\u4ee3\u7801\u6bb5\u4e2d，\u5b9a\u4e49\u4e86DNS\u62a5\u6587\u5934\u90e8\u7684\u7ed3\u6784\u4f53 DNSHeader ，\u4ee5\u53ca\u4ece\u7f51\u7edc\u5b57\u8282\u5e8f\u8f6c\u6362\u4e3a\u672c\u5730\u5b57\u8282\u5e8f\u7684\u51fd\u6570 dns_header_unswap \u3002\u901a\u8fc7\u7ed3\u6784\u4f53，\u6211\u4eec\u53ef\u4ee5\u65b9\u4fbf\u5730\u8bbf\u95eeDNS\u62a5\u6587\u5934\u90e8\u7684\u5404\u4e2a\u5b57\u6bb5，\u5e76\u6839\u636e\u8fd9\u4e9b\u4fe1\u606f\u89e3\u6790\u6574\u4e2aDNS\u62a5\u6587\u3002 <\/p>\n
\u7f16\u5199\u4e00\u4e2aDNS\u62a5\u6587\u89e3\u6790\u5668\u65f6，\u9700\u8981\u8003\u8651\u4ee5\u4e0b\u51e0\u4e2a\u5173\u952e\u6b65\u9aa4： <\/p>\n
\u6784\u9020DNS\u62a5\u6587\u6d89\u53ca\u6839\u636e\u67e5\u8be2\u8bf7\u6c42，\u751f\u6210\u76f8\u5e94\u7684DNS\u67e5\u8be2\u6d88\u606f\u3002\u9a8c\u8bc1\u5219\u662f\u5bf9\u6536\u5230\u7684\u54cd\u5e94\u62a5\u6587\u8fdb\u884c\u68c0\u67e5，\u786e\u4fdd\u5b83\u4eec\u662f\u6709\u6548\u548c\u53ef\u4fe1\u7684\u3002\u9a8c\u8bc1\u901a\u5e38\u6d89\u53ca\u68c0\u67e5\u62a5\u6587ID\u3001\u6807\u5fd7\u4f4d\u548c\u8d44\u6e90\u8bb0\u5f55\u7684\u6570\u636e\u4e00\u81f4\u6027\u3002\u5982\u679c\u9700\u8981，\u8fd8\u53ef\u4ee5\u8fdb\u884c\u6570\u5b57\u7b7e\u540d\u9a8c\u8bc1\u6216\u52a0\u5bc6\u5904\u7406\u3002 <\/p>\n
\u4e0b\u9762\u662f\u4e00\u4e2a\u4f7f\u7528C\u8bed\u8a00\u6784\u9020DNS\u67e5\u8be2\u62a5\u6587\u7684\u793a\u4f8b\u4ee3\u7801： <\/p>\n
#include <stdio.h>
\n#include <string.h>
\n#include <arpa\/inet.h><\/p>\n
\/\/ DNS\u62a5\u6587\u6784\u9020\u51fd\u6570\u793a\u4f8b
\nvoid construct_dns_query(unsigned char *packet, const char *domain, int type) {
\n int offset = 0;
\n int name_len;
\n \/\/ DNS\u5934\u90e8
\n packet[offset++] = 0x01; \/\/ \u6807\u8bc6\u7b26\u9ad8\u5b57\u8282
\n packet[offset++] = 0x00; \/\/ \u6807\u8bc6\u7b26\u4f4e\u5b57\u8282
\n packet[offset++] = 0x00; \/\/ QR = 0, \u8868\u793a\u67e5\u8be2
\n packet[offset++] = 0x01; \/\/ OPCODE = 1, \u6807\u51c6\u67e5\u8be2
\n packet[offset++] = 0x00; \/\/ AA, RD, TC, RA\u5747\u4e3a0
\n packet[offset++] = 0x00; \/\/ Z\u7f6e\u4e3a0
\n packet[offset++] = 0x01; \/\/ QDCOUNT = 1
\n packet[offset++] = 0x00; \/\/ ANCOUNT, NSCOUNT, ARCOUNT\u5747\u4e3a0
\n \/\/ \u95ee\u9898\u533a\u57df\u5f00\u59cb
\n name_len = strlen(domain);
\n packet[offset++] = name_len; \/\/ \u9996\u5b57\u8282\u4e3a\u57df\u540d\u957f\u5ea6
\n while(name_len > 0) {
\n memcpy(packet + offset, domain, name_len); \/\/ \u590d\u5236\u57df\u540d\u5230\u62a5\u6587\u4e2d
\n offset += name_len;
\n packet[offset++] = 0; \/\/ \u57df\u540d\u7ed3\u675f\u7b26
\n name_len = strlen(domain + offset);
\n }
\n \/\/ \u95ee\u9898\u7c7b\u578b
\n packet[offset++] = type >> 8; \/\/ \u7c7b\u578b\u9ad8\u5b57\u8282
\n packet[offset++] = type & 0xFF; \/\/ \u7c7b\u578b\u4f4e\u5b57\u8282
\n packet[offset++] = 0x00; \/\/ \u7c7b\u522b\u4e3a0x0001
\n packet[offset++] = 0x01;
\n}<\/p>\n
int main() {
\n const char *domain = "example.com";
\n int type = 0x0001; \/\/ \u7c7b\u578bA\u8bb0\u5f55
\n unsigned char packet[512]; \/\/ \u5047\u8bbe\u8db3\u591f\u5927\u7684\u7f13\u51b2\u533a\u5b58\u50a8DNS\u62a5\u6587
\n \/\/ \u6784\u9020DNS\u67e5\u8be2\u62a5\u6587
\n construct_dns_query(packet, domain, type);
\n \/\/ …\u540e\u7eed\u53d1\u9001\u62a5\u6587\u548c\u63a5\u6536\u54cd\u5e94
\n return 0;
\n}<\/p>\n
\u5728\u6b64\u4ee3\u7801\u6bb5\u4e2d，\u6211\u4eec\u5b9a\u4e49\u4e86\u4e00\u4e2a\u6784\u9020\u51fd\u6570 construct_dns_query ，\u5b83\u6784\u9020\u4e00\u4e2a\u9488\u5bf9\u7ed9\u5b9a\u57df\u540d\u548c\u7c7b\u578b\u7684\u6807\u51c6DNS\u67e5\u8be2\u62a5\u6587\u3002\u51fd\u6570\u9996\u5148\u586b\u5145DNS\u62a5\u6587\u5934\u90e8，\u5e76\u6784\u5efa\u95ee\u9898\u533a\u57df，\u5305\u62ec\u57df\u540d\u548c\u67e5\u8be2\u7c7b\u578b\u3002\u6ce8\u610f，\u57df\u540d\u5b57\u7b26\u4e32\u5e94\u5305\u62ec\u70b9\u5206\u9694\u7684\u6807\u7b7e，\u6bcf\u4e2a\u6807\u7b7e\u7684\u957f\u5ea6\u5e94\u6b63\u786e\u8868\u793a\u3002\u51fd\u6570\u6700\u540e\u8ba1\u7b97\u51fa\u57df\u540d\u7684\u603b\u957f\u5ea6，\u5e76\u5c06\u6b64\u957f\u5ea6\u7528\u4e8e\u586b\u5145\u62a5\u6587\u3002 <\/p>\n
\u5728\u5b9e\u9645\u5e94\u7528\u4e2d，DNS\u67e5\u8be2\u62a5\u6587\u6784\u9020\u540e，\u901a\u5e38\u4f1a\u901a\u8fc7socket\u8fdb\u884c\u53d1\u9001，\u5e76\u7b49\u5f85\u54cd\u5e94\u3002\u54cd\u5e94\u7684\u89e3\u6790\u5904\u7406\u5c06\u4f7f\u7528\u524d\u6587\u63d0\u5230\u7684\u65b9\u6cd5\u6765\u5b8c\u6210\u3002 <\/p>\n
\u5728DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u4e2d，\u8bf7\u6c42\u8f6c\u53d1\u673a\u5236\u662f\u786e\u4fdd\u5ba2\u6237\u7aef\u67e5\u8be2\u8bf7\u6c42\u80fd\u591f\u6b63\u786e\u3001\u9ad8\u6548\u5730\u88ab\u5904\u7406\u7684\u6838\u5fc3\u7ec4\u4ef6\u3002\u5728\u8f6c\u53d1\u8fc7\u7a0b\u4e2d，\u4e2d\u7ee7\u670d\u52a1\u5668\u9996\u5148\u63a5\u6536\u6765\u81ea\u5ba2\u6237\u7aef\u7684DNS\u67e5\u8be2\u8bf7\u6c42，\u7136\u540e\u6839\u636e\u914d\u7f6e\u7684\u8f6c\u53d1\u7b56\u7565，\u5c06\u8bf7\u6c42\u8f6c\u53d1\u5230\u4e0a\u6e38\u7684DNS\u670d\u52a1\u5668\u3002 <\/p>\n
\u8f6c\u53d1\u7b56\u7565\u901a\u5e38\u5305\u62ec： <\/p>\n
\u5b9e\u73b0\u8fd9\u4e9b\u7b56\u7565\u901a\u5e38\u9700\u8981\u5bf9\u8bf7\u6c42\u8fdb\u884c\u8bb0\u5f55\u3001\u76d1\u63a7\u4e0a\u6e38\u670d\u52a1\u5668\u7684\u72b6\u6001\u3001\u53ca\u65f6\u66f4\u65b0\u8f6c\u53d1\u89c4\u5219\u7b49\u3002 <\/p>\n
\u4e3a\u4e86\u66f4\u597d\u5730\u5904\u7406\u5927\u91cf\u5e76\u53d1\u8bf7\u6c42\u5e76\u63d0\u9ad8\u7cfb\u7edf\u7684\u53ef\u7528\u6027，\u8d1f\u8f7d\u5747\u8861\u548c\u6545\u969c\u8f6c\u79fb\u673a\u5236\u663e\u5f97\u5c24\u4e3a\u91cd\u8981\u3002\u8d1f\u8f7d\u5747\u8861\u53ef\u4ee5\u4fdd\u8bc1\u8bf7\u6c42\u5728\u591a\u4e2a\u4e0a\u6e38DNS\u670d\u52a1\u5668\u4e4b\u95f4\u5747\u5300\u5206\u5e03，\u4ece\u800c\u63d0\u9ad8\u6574\u4f53\u67e5\u8be2\u6548\u7387\u3002\u6545\u969c\u8f6c\u79fb\u5219\u662f\u5728\u4e0a\u6e38DNS\u670d\u52a1\u5668\u51fa\u73b0\u6545\u969c\u65f6，\u786e\u4fdd\u5ba2\u6237\u7aef\u4ecd\u7136\u80fd\u591f\u5f97\u5230\u6709\u6548\u7684\u54cd\u5e94\u3002 <\/p>\n
\u5b9e\u73b0\u8d1f\u8f7d\u5747\u8861\u548c\u6545\u969c\u8f6c\u79fb\u4e00\u822c\u4f1a\u7528\u5230\u4ee5\u4e0b\u6280\u672f： <\/p>\n
DNS\u54cd\u5e94\u5904\u7406\u5305\u62ec\u5bf9\u4ece\u4e0a\u6e38DNS\u670d\u52a1\u5668\u8fd4\u56de\u7684\u6570\u636e\u8fdb\u884c\u5c01\u88c5\u4e0e\u89e3\u5305\u3002\u5c01\u88c5\u8fc7\u7a0b\u901a\u5e38\u6d89\u53ca\u586b\u5145DNS\u54cd\u5e94\u62a5\u6587\u7684\u6807\u51c6\u5b57\u6bb5，\u5982ID\u3001\u6807\u5fd7\u4f4d\u3001\u8d44\u6e90\u8bb0\u5f55\u6570\u7b49\u3002\u89e3\u5305\u8fc7\u7a0b\u5219\u9700\u8981\u89e3\u6790\u8fd9\u4e9b\u5b57\u6bb5，\u5e76\u6839\u636e\u8fd4\u56de\u7684\u7ed3\u679c\u66f4\u65b0\u4e2d\u7ee7\u670d\u52a1\u5668\u7684\u7f13\u5b58\u3002 <\/p>\n
\u5728C\u8bed\u8a00\u4e2d，\u8fd9\u6d89\u53ca\u5230\u5bf9\u6570\u636e\u7684\u5185\u5b58\u64cd\u4f5c，\u5305\u62ec： <\/p>\n
\u4e3a\u4e86\u4fdd\u8bc1DNS\u67e5\u8be2\u7684\u54cd\u5e94\u6570\u636e\u7684\u5b89\u5168\u6027\u548c\u5b8c\u6574\u6027，\u9700\u8981\u5bf9\u54cd\u5e94\u6570\u636e\u8fdb\u884c\u6821\u9a8c\u3002\u5e38\u7528\u7684\u65b9\u6cd5\u5305\u62ec： <\/p>\n
\u5b9e\u73b0\u6821\u9a8c\u901a\u5e38\u9700\u8981\u7f16\u5199\u76f8\u5e94\u7684\u51fd\u6570\u6765\u8ba1\u7b97\u6821\u9a8c\u548c\u6216\u8fdb\u884c\u7b7e\u540d\u9a8c\u8bc1\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f，DNSSEC\u8981\u6c42\u5728\u89e3\u6790\u5668\u548c\u670d\u52a1\u5668\u7aef\u90fd\u8fdb\u884c\u76f8\u5e94\u7684\u652f\u6301\u3002 <\/p>\n
\u4ee5\u4e0b\u662f\u4f7f\u7528C\u8bed\u8a00\u7684\u4e00\u4e2a\u7b80\u5355\u6821\u9a8c\u548c\u8ba1\u7b97\u793a\u4f8b\u4ee3\u7801： <\/p>\n
unsigned short calculate_checksum(unsigned char *buffer, int length) {
\n unsigned int sum = 0;
\n unsigned short result;<\/p>\n
for (sum = 0; length > 1; length -= 2) {
\n sum += buffer[0] * 256 + buffer[1];
\n buffer += 2;
\n }
\n if (length > 0)
\n sum += buffer[0]; \/\/ \u5bf9\u4e8e\u5355\u5b57\u8282\u7684\u60c5\u51b5，\u76f4\u63a5\u52a0\u4e0a\u6700\u540e\u4e00\u4e2a\u5b57\u8282<\/p>\n
sum = (sum >> 16) + (sum & 0xFFFF); \/\/ \u5c06\u9ad816\u4f4d\u548c\u4f4e16\u4f4d\u76f8\u52a0
\n sum += (sum >> 16); \/\/ \u518d\u6b21\u5904\u7406\u8fdb\u4f4d<\/p>\n
result = ~sum; \/\/ \u5bf9\u6700\u7ec8\u7684\u6c42\u548c\u7ed3\u679c\u53d6\u53cd<\/p>\n
return result;
\n}<\/p>\n
\u672c\u7ae0\u8282\u4e2d，\u6211\u4eec\u6df1\u5165\u63a2\u8ba8\u4e86DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u4e2d\u8bf7\u6c42\u8f6c\u53d1\u548c\u54cd\u5e94\u5904\u7406\u7684\u673a\u5236\u3002\u5728\u4e0b\u4e00\u7ae0\u8282，\u6211\u4eec\u5c06\u7ee7\u7eed\u63a2\u8ba8\u9519\u8bef\u5904\u7406\u673a\u5236，\u4ee5\u53ca\u5982\u4f55\u5728\u4e2d\u7ee7\u670d\u52a1\u5668\u4e2d\u6709\u6548\u5730\u8bc6\u522b\u3001\u5206\u7c7b\u5e76\u54cd\u5e94\u9519\u8bef\u60c5\u51b5\u3002 <\/p>\n
\u672c\u6587\u8fd8\u6709\u914d\u5957\u7684\u7cbe\u54c1\u8d44\u6e90，\u70b9\u51fb\u83b7\u53d6 <\/p>\n
\u7b80\u4ecb：DNS（\u57df\u540d\u7cfb\u7edf）\u4f5c\u4e3a\u4e92\u8054\u7f51\u57fa\u7840\u670d\u52a1，\u8d1f\u8d23\u57df\u540d\u4e0eIP\u5730\u5740\u8f6c\u6362\u3002DNS\u4e2d\u7ee7\u670d\u52a1\u5668\u5728\u6b64\u8fc7\u7a0b\u4e2d\u8f6c\u53d1\u8bf7\u6c42\u81f3\u9002\u5f53DNS\u670d\u52a1\u5668\u3002\u672c\u5b9e\u9a8c\u4f7f\u7528C\u8bed\u8a00\u7f16\u5199DNS\u4e2d\u7ee7\u670d\u52a1\u5668，\u65e8\u5728\u901a\u8fc7\u5b9e\u8df5\u52a0\u6df1\u5bf9DNS\u5de5\u4f5c\u539f\u7406\u7684\u7406\u89e3\u3002\u5b9e\u9a8c\u5305\u62ec\u7f51\u7edc\u5957\u63a5\u5b57\u7f16\u7a0b\u3001DNS\u62a5\u6587\u89e3\u6790\u3001\u8bf7\u6c42\u8f6c\u53d1\u3001\u54cd\u5e94\u5904\u7406\u53ca\u9519\u8bef\u5904\u7406\u3002\u5b9e\u9a8c\u6587\u6863\u4e2d\u8be6\u7ec6\u63cf\u8ff0\u4e86\u5b9e\u9a8c\u76ee\u7684\u3001\u7406\u8bba\u80cc\u666f\u3001\u8bbe\u8ba1\u601d\u8def\u3001\u5b9e\u73b0\u6b65\u9aa4\u3001\u95ee\u9898\u89e3\u51b3\u65b9\u6cd5\u53ca\u7ed3\u679c\u5206\u6790，\u63d0\u4f9b\u4e86\u6d4b\u8bd5\u7528\u4f8b\u4ee5\u9a8c\u8bc1\u670d\u52a1\u5668\u6027\u80fd\u548c\u9c81\u68d2\u6027\u3002\u6574\u4f53\u4e0a，\u8be5\u5b9e\u9a8c\u5e2e\u52a9\u5b66\u4e60\u8005\u7406\u89e3DNS\u5de5\u4f5c\u673a\u5236，\u63d0\u9ad8\u7f51\u7edc\u7f16\u7a0b\u548c\u95ee\u9898\u5904\u7406\u80fd\u529b\u3002 <\/p>\n
\u672c\u6587\u8fd8\u6709\u914d\u5957\u7684\u7cbe\u54c1\u8d44\u6e90，\u70b9\u51fb\u83b7\u53d6 <\/p><\/p>\n","protected":false},"excerpt":{"rendered":"
\u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb836\u6b21\uff0c\u70b9\u8d5e7\u6b21\uff0c\u6536\u85cf22\u6b21\u3002\u57df\u540d\u7cfb\u7edf\uff08DNS\uff09\u662f\u4e92\u8054\u7f51\u57fa\u7840\u8bbe\u65bd\u7684\u6838\u5fc3\u90e8\u5206\uff0c\u8d1f\u8d23\u57df\u540d\u4e0eIP\u5730\u5740\u4e4b\u95f4\u7684\u8f6c\u6362\u3002DNS\u4e2d\u7ee7\u670d\u52a1\u5668\uff0c\u4f5c\u4e3a\u57df\u540d\u89e3\u6790\u8fc7\u7a0b\u4e2d\u7684\u4e00\u4e2a\u4e2d\u4ecb\uff0c\u5176\u4e3b\u8981\u4f5c\u7528\u5728\u4e8e\u51cf\u8f7b\u6839\u57df\u540d\u670d\u52a1\u5668\u7684\u538b\u529b\uff0c\u63d0\u9ad8\u57df\u540d\u89e3\u6790\u7684\u6548\u7387\uff0c\u5e76\u80fd\u5728\u5c40\u57df\u7f51\u5185\u5b9e\u73b0\u7f13\u5b58\u89e3\u6790\u7ed3\u679c\u6765\u51cf\u5c11\u5bf9\u5916\u90e8\u7f51\u7edc\u7684\u4f9d\u8d56\u3002Internet\u534f\u8bae\uff08IP\uff09\u662f\u4e92\u8054\u7f51\u7684\u6838\u5fc3\u534f\u8bae\u4e4b\u4e00\uff0c\u5b83\u89c4\u5b9a\u4e86\u4e92\u8054\u7f51\u4e0a\u6570\u636e\u5305\u7684\u683c\u5f0f\u548c\u8f6c\u53d1\u65b9\u5f0f\u3002IP\u534f\u8bae\u786e\u4fdd\u6570\u636e\u5305\u80fd\u591f\u4ece\u6e90\u4e3b\u673a\u4f20\u8f93\u5230\u76ee\u7684\u4e3b\u673a\uff0c\u4f46\u4e0d\u4fdd\u8bc1\u4f20\u8f93\u7684\u53ef\u9760\u6027\u548c\u987a\u5e8f\uff0c\u8fd9\u7531\u4e0a\u5c42\u7684\u4f20\u8f93\u5c42\u534f\u8bae\u5982TCP\u6765\u5b9e\u73b0\u3002IP\u534f\u8bae\u6709\u591a\u4e2a\u7248\u672c\uff0c\u5305\u62ecIPv4\u548cIPv6\u3002<\/p>\n","protected":false},"author":2,"featured_media":41404,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"topic":[],"class_list":["post-41406","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-server"],"yoast_head":"\n