{"id":4213,"date":"2021-11-26T14:28:42","date_gmt":"2021-11-26T22:28:42","guid":{"rendered":"https:\/\/www.xh86.me\/?p=4213"},"modified":"2021-11-26T14:34:02","modified_gmt":"2021-11-26T22:34:02","slug":"%e3%80%90%e9%a1%b9%e7%9b%ae%e6%a1%88%e4%be%8b%e3%80%91%e8%b6%85%e8%af%a6%e7%bb%86%e7%9a%84%e7%bd%91%e7%bb%9c%e6%8a%93%e5%8c%85%e5%ae%9e%e6%88%98%e6%a1%88%e4%be%8b%e5%88%86%e4%ba%ab","status":"publish","type":"post","link":"https:\/\/www.xh86.me\/?p=4213","title":{"rendered":"\u8be6\u7ec6\u7684\u7f51\u7edc\u6293\u5305\u5b9e\u6218\u6848\u4f8b\u5206\u4eab"},"content":{"rendered":"
\n
\n
<\/section>\n
\n

\u7f51\u7edc\u5b9e\u6218\u5de5\u5177\uff1alinux :tcpdump \/ window:Wireshark<\/p>\n

\n

\u8fd9\u4e24\u8005\u5b9e\u9645\u4e0a\u662f\u642d\u914d\u4f7f\u7528\u7684\uff0c\u5148\u7528 tcpdump \u547d\u4ee4\u5728 Linux \u670d\u52a1\u5668\u4e0a\u6293\u5305\uff0c\u63a5\u7740\u628a\u6293\u5305\u7684\u6587\u4ef6\u62d6\u51fa\u5230 Windows \u7535\u8111\u540e\uff0c\u7528 Wireshark \u53ef\u89c6\u5316\u5206\u6790\u3002\u5f53\u7136\uff0c\u5982\u679c\u4f60\u662f\u5728 Windows \u4e0a\u6293\u5305\uff0c\u53ea\u9700\u8981\u7528 Wireshark \u5de5\u5177\u5c31\u53ef\u4ee5\u3002<\/p>\n

\n

tcpdump\u4f7f\u7528\u65b9\u6cd5<\/strong><\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n
<\/div><\/section>\n<\/section>\n
\n

\n<\/section>\n

\n
\n

tcpdump \u5728 Linux \u4e0b\u5982\u4f55\u6293\u5305\uff1f<\/strong><\/p>\n<\/section>\n<\/section>\n

\n
\n
\n
\n
\n
\n
\n
\n
<\/section>\n<\/section>\n<\/section>\n<\/section>\n
\n
\n
\n
<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n
\n

\n

tcpdump \u63d0\u4f9b\u4e86\u5927\u91cf\u7684\u9009\u9879\u4ee5\u53ca\u5404\u5f0f\u5404\u6837\u7684\u8fc7\u6ee4\u8868\u8fbe\u5f0f\uff0c\u6765\u5e2e\u52a9\u4f60\u6293\u53d6\u6307\u5b9a\u7684\u6570\u636e\u5305\uff0c\u4e0d\u8fc7\u4e0d\u8981\u62c5\u5fc3\uff0c\u53ea\u9700\u8981\u638c\u63e1\u4e00\u4e9b\u5e38\u7528\u9009\u9879\u548c\u8fc7\u6ee4\u8868\u8fbe\u5f0f\uff0c\u5c31\u53ef\u4ee5\u6ee1\u8db3\u5927\u90e8\u5206\u573a\u666f\u7684\u9700\u8981\u4e86\u3002\u5047\u8bbe\u6211\u4eec\u8981\u6293\u53d6\u4e0b\u9762\u7684 ping \u7684\u6570\u636e\u5305\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u8981\u6293\u53d6\u4e0a\u9762\u7684 ping \u547d\u4ee4\u6570\u636e\u5305\uff0c\u9996\u5148\u6211\u4eec\u8981\u77e5\u9053 ping \u7684\u6570\u636e\u5305\u662f icmp \u534f\u8bae\uff0c\u63a5\u7740\u5728\u4f7f\u7528 tcpdump\u6293\u5305\u7684\u65f6\u5019\uff0c\u5c31\u53ef\u4ee5\u6307\u5b9a\u53ea\u6293 icmp \u534f\u8bae\u7684\u6570\u636e\u5305\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u90a3\u4e48\u5f53 tcpdump \u6293\u53d6\u5230 icmp \u6570\u636e\u5305\u540e\uff0c \u8f93\u51fa\u683c\u5f0f\u5982\u4e0b\uff1a\u65f6\u95f4\u6233\u534f\u8bae\u6e90\u5730\u5740.\u6e90\u7aef\u53e3 > \u76ee\u7684\u5730\u5740.\u76ee\u7684\u7aef\u53e3\u7f51\u7edc\u5305\u8be6\u7ec6\u4fe1\u606f<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u4ece tcpdump \u6293\u53d6\u7684 icmp \u6570\u636e\u5305\uff0c\u6211\u4eec\u5f88\u6e05\u695a\u7684\u770b\u5230 icmp echo \u7684\u4ea4\u4e92\u8fc7\u7a0b\u4e86\uff0c\u9996\u5148\u53d1\u9001\u65b9\u53d1\u8d77\u4e86ICMP echo request \u8bf7\u6c42\u62a5\u6587\uff0c\u63a5\u6536\u65b9\u6536\u5230\u540e\u56de\u4e86\u4e00\u4e2a ICMP echo reply \u54cd\u5e94\u62a5\u6587\uff0c\u4e4b\u540e seq \u662f\u9012\u589e\u7684\u3002<\/p>\n

\n<\/section>\n

\n
\n

Wireshark \u5de5\u5177\u5982\u4f55\u5206\u6790\u6570\u636e\u5305\uff1f<\/strong><\/p>\n<\/section>\n<\/section>\n

\n
\n
\n
\n
\n
\n
\n
\n
<\/section>\n<\/section>\n<\/section>\n<\/section>\n
\n
\n
\n
<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n
\n

\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u63a5\u7740\u628a ping.pcap \u6587\u4ef6\u62d6\u5230\u7535\u8111\uff0c\u518d\u7528 Wireshark \u6253\u5f00\u5b83\u3002\u6253\u5f00\u540e\uff0c\u4f60\u5c31\u53ef\u4ee5\u770b\u5230\u4e0b\u9762\u8fd9\u4e2a\u754c\u9762\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u5728 Wireshark \u7684\u9875\u9762\u91cc\uff0c\u53ef\u4ee5\u66f4\u52a0\u76f4\u89c2\u7684\u5206\u6790\u6570\u636e\u5305\uff0c\u4e0d\u4ec5\u5c55\u793a\u5404\u4e2a\u7f51\u7edc\u5305\u7684\u5934\u90e8\u4fe1\u606f\uff0c\u8fd8\u4f1a\u7528\u4e0d\u540c\u7684\u989c\u8272\u6765\u533a\u5206\u4e0d\u540c\u7684\u534f\u8bae\uff0c\u7531\u4e8e\u8fd9\u6b21\u6293\u5305\u53ea\u6709 ICMP \u534f\u8bae\uff0c\u6240\u4ee5\u53ea\u6709\u7d2b\u8272\u7684\u6761\u76ee\u3002\u63a5\u7740\u5728\u7f51\u7edc\u5305\u5217\u8868\u4e2d\u9009\u62e9\u67d0\u4e00\u4e2a\u7f51\u7edc\u5305\u540e\uff0c\u5728\u5176\u4e0b\u9762\u7684\u7f51\u7edc\u5305\u8be6\u60c5\u4e2d\uff0c\u53ef\u4ee5\u66f4\u6e05\u695a\u7684\u770b\u5230\uff0c\u8fd9\u4e2a\u7f51\u7edc\u5305\u5728\u534f\u8bae\u6808\u5404\u5c42\u7684\u8be6\u7ec6\u4fe1\u606f\u3002<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u4ece ping \u7684\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u770b\u5230\u7f51\u7edc\u5206\u5c42\u5c31\u50cf\u6709\u5e8f\u7684\u5206\u5de5\uff0c\u6bcf\u4e00\u5c42\u90fd\u6709\u81ea\u5df1\u7684\u8d23\u4efb\u8303\u56f4\u548c\u4fe1\u606f\uff0c\u4e0a\u5c42\u534f\u8bae\u5b8c\u6210\u5de5\u4f5c\u540e\u5c31\u4ea4\u7ed9\u4e0b\u4e00\u5c42\uff0c\u6700\u7ec8\u5f62\u6210\u4e00\u4e2a\u5b8c\u6574\u7684\u7f51\u7edc\u5305\u3002<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n<\/section>\n

\n
\n

TCP\u4e09\u6b21\u63e1\u624b\u6293\u5305<\/strong><\/p>\n<\/section>\n<\/section>\n

\n
\n
\n
\n
\n
\n
\n
\n
<\/section>\n<\/section>\n<\/section>\n<\/section>\n
\n
\n
\n
<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n
\n

\n

\u672c\u6b21\u4f8b\u5b50\uff0c\u6211\u4eec\u5c06\u8981\u8bbf\u95ee\u7684 http:\/\/192.168.3.200 \u670d\u52a1\u7aef\u3002\u5728\u7ec8\u7aef\u4e00\u7528 tcpdump \u547d\u4ee4\u6293\u53d6\u6570\u636e\u5305\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u4f7f\u7528 Wireshark \u6253\u5f00 http.pcap \u540e\uff0c\u4f60\u5c31\u53ef\u4ee5\u5728 Wireshark \u4e2d\uff0c\u770b\u5230\u5982\u4e0b\u7684\u754c\u9762\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

Wireshark \u53ef\u4ee5\u7528\u65f6\u5e8f\u56fe\u7684\u65b9\u5f0f\u663e\u793a\u6570\u636e\u5305\u4ea4\u4e92\u7684\u8fc7\u7a0b\uff0c\u4ece\u83dc\u5355\u680f\u4e2d\uff0c\u70b9\u51fb \u7edf\u8ba1 (Statistics) -> \u6d41\u91cf\u56fe(Flow Graph)\uff0c\u7136\u540e\uff0c\u5728\u5f39\u51fa\u7684\u754c\u9762\u4e2d\u7684\u300c\u6d41\u91cf2\u7c7b\u578b\u300d\u9009\u62e9 \u300cTCP Flows\u300d\uff0c\u4f60\u53ef\u4ee5\u66f4\u6e05\u6670\u7684\u770b\u5230\uff0c\u6574\u4e2a\u8fc7\u7a0b\u4e2d TCP \u6d41\u7684\u6267\u884c\u8fc7\u7a0b\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u4f60\u53ef\u80fd\u4f1a\u597d\u5947\uff0c\u4e3a\u4ec0\u4e48\u4e09\u6b21\u63e1\u624b\u8fde\u63a5\u8fc7\u7a0b\u7684 Seq \u662f 0 \uff1f<\/span><\/span><\/p>\n

\n

\u5b9e\u9645\u4e0a\u662f\u56e0\u4e3a Wireshark \u5de5\u5177\u5e2e\u6211\u4eec\u505a\u4e86\u4f18\u5316\uff0c\u5b83\u9ed8\u8ba4\u663e\u793a\u7684\u662f\u5e8f\u5217\u53f7 seq \u662f\u76f8\u5bf9\u503c\uff0c\u800c\u4e0d\u662f\u771f\u5b9e\u503c\u3002\u5982\u679c\u4f60\u60f3\u770b\u5230\u5b9e\u9645\u7684\u5e8f\u5217\u53f7\u7684\u503c\uff0c\u53ef\u4ee5\u53f3\u952e\u83dc\u5355\uff0c \u7136\u540e\u627e\u5230\u300c\u534f\u8bae\u9996\u9009\u9879\u300d\uff0c\u63a5\u7740\u627e\u5230\u300cRelativeSeq\u300d\u540e\uff0c\u628a\u5b83\u7ed9\u53d6\u6d88\uff0c\u64cd\u4f5c\u5982\u4e0b\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n
<\/div><\/section>\n<\/section>\n
\n

\n<\/section>\n

\n
\n

TCP\u56db\u6b21\u6325\u624b\u6293\u5305<\/strong><\/p>\n<\/section>\n<\/section>\n

\n
\n
\n
\n
\n
\n
\n
\n
<\/section>\n<\/section>\n<\/section>\n<\/section>\n
\n
\n
\n
<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n
\n

\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u4e3a\u4ec0\u4e48\u6293\u5230\u7684 TCP \u6325\u624b\u662f\u4e09\u6b21\uff0c\u800c\u4e0d\u662f\u4e66\u4e0a\u8bf4\u7684\u56db\u6b21\uff1f<\/span><\/p>\n

\n

\u56e0\u4e3a\u670d\u52a1\u5668\u7aef\u6536\u5230\u5ba2\u6237\u7aef\u7684 FIN \u540e\uff0c\u670d\u52a1\u5668\u7aef\u540c\u65f6\u4e5f\u8981\u5173\u95ed\u8fde\u63a5\uff0c\u8fd9\u6837\u5c31\u53ef\u4ee5\u628a ACK \u548c FIN \u5408\u5e76\u5230\u4e00\u8d77\u53d1\u9001\uff0c\u8282\u7701\u4e86\u4e00\u4e2a\u5305\uff0c\u53d8\u6210\u4e86\u201c\u4e09\u6b21\u6325\u624b\u201d\u3002<\/span>\u800c\u901a\u5e38\u60c5\u51b5\u4e0b\uff0c\u670d\u52a1\u5668\u7aef\u6536\u5230\u5ba2\u6237\u7aef\u7684 FIN \u540e\uff0c\u5f88\u53ef\u80fd\u8fd8\u6ca1\u53d1\u9001\u5b8c\u6570\u636e\uff0c\u6240\u4ee5\u5c31\u4f1a\u5148\u56de\u590d\u5ba2\u6237\u7aef\u4e00\u4e2aACK \u5305\uff0c\u7a0d\u7b49\u4e00\u4f1a\u513f\uff0c\u5b8c\u6210\u6240\u6709\u6570\u636e\u5305\u7684\u53d1\u9001\u540e\uff0c\u624d\u4f1a\u53d1\u9001 FIN \u5305\uff0c\u8fd9\u4e5f\u5c31\u662f\u56db\u6b21\u6325\u624b\u4e86\u3002<\/span><\/p>\n

\n

\u5982\u4e0b\u56fe\uff0c\u5c31\u662f\u56db\u6b21\u6325\u624b\u7684\u8fc7\u7a0b\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n<\/section>\n

\n
\n

TCP \u4e09\u6b21\u63e1\u624b\u5f02\u5e38\u60c5\u51b5\u5b9e\u6218\u5206\u6790<\/strong><\/p>\n<\/section>\n<\/section>\n

\n
\n
\n
\n
\n
\n
\n
\n
<\/section>\n<\/section>\n<\/section>\n<\/section>\n
\n
\n
\n
<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n<\/section>\n
\n

\n

\u672c\u6b21\u5b9e\u9a8c\u7528\u4e86\u4e24\u53f0\u865a\u62df\u673a\uff0c\u4e00\u53f0\u4f5c\u4e3a\u670d\u52a1\u7aef\uff0c\u4e00\u53f0\u4f5c\u4e3a\u5ba2\u6237\u7aef\uff0c\u5b83\u4eec\u7684\u5173\u7cfb\u5982\u4e0b\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u5b9e\u9a8c\u4e00\uff1aTCP \u7b2c\u4e00\u6b21\u63e1\u624b SYN \u4e22\u5305<\/strong><\/p>\n

\n

\u4e3a\u4e86\u6a21\u62df TCP \u7b2c\u4e00\u6b21\u63e1\u624b SYN \u4e22\u5305\u7684\u60c5\u51b5\uff0c\u6211\u662f\u5728\u62d4\u6389\u670d\u52a1\u5668\u7684\u7f51\u7ebf\u540e\uff0c\u7acb\u523b\u5728\u5ba2\u6237\u7aef\u6267\u884c curl \u547d\u4ee4<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u5176\u95f4 tcpdump \u6293\u5305\u7684\u547d\u4ee4\u5982\u4e0b\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u8fc7\u4e86\u4e00\u4f1a\uff0c curl \u8fd4\u56de\u4e86\u8d85\u65f6\u8fde\u63a5\u7684\u9519\u8bef\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u4ece date \u8fd4\u56de\u7684\u65f6\u95f4\uff0c\u53ef\u4ee5\u53d1\u73b0\u5728\u8d85\u65f6\u63a5\u8fd1 1 \u5206\u949f\u7684\u65f6\u95f4\u540e\uff0ccurl \u8fd4\u56de\u4e86\u9519\u8bef\u3002\u63a5\u7740\uff0c\u628a tcp_sys_timeout.pcap \u6587\u4ef6\u7528 Wireshark \u6253\u5f00\u5206\u6790\uff0c\u663e\u793a\u5982\u4e0b\u56fe\uff1a<\/p>\n<\/section>\n

\n
<\/div><\/section>\n<\/section>\n
\n

\n

\u4ece\u4e0a\u56fe\u53ef\u4ee5\u53d1\u73b0\uff0c \u5ba2\u6237\u7aef\u53d1\u8d77\u4e86 SYN \u5305\u540e\uff0c\u4e00\u76f4\u6ca1\u6709\u6536\u5230\u670d\u52a1\u7aef\u7684 ACK \uff0c\u6240\u4ee5\u4e00\u76f4\u8d85\u65f6\u91cd\u4f20\u4e86\u6b21\uff0c\u5e76\u4e14\u6bcf\u6b21 RTO \u8d85\u65f6\u65f6\u95f4\u662f\u4e0d\u540c\u7684\uff1a<\/p>\n

    \n
  • \n

    \u7b2c\u4e00\u6b21\u662f\u5728 1 \u79d2\u8d85\u65f6\u91cd\u4f20<\/p>\n<\/li>\n

  • \n

    \u7b2c\u4e8c\u6b21\u662f\u5728 3 \u79d2\u8d85\u65f6\u91cd\u4f20<\/p>\n<\/li>\n

  • \n

    \u7b2c\u4e09\u6b21\u662f\u5728 7 \u79d2\u8d85\u65f6\u91cd\u4f20<\/p>\n<\/li>\n

  • \n

    \u7b2c\u56db\u6b21\u662f\u5728 15 \u79d2\u8d85\u65f6\u91cd\u4f20<\/p>\n<\/li>\n

  • \n

    \u7b2c\u4e94\u6b21\u662f\u5728 31 \u79d2\u8d85\u65f6\u91cd\u4f20<\/p>\n<\/li>\n<\/ul>\n

    \n

    \u53ef\u4ee5\u53d1\u73b0\uff0c\u6bcf\u6b21\u8d85\u65f6\u65f6\u95f4 RTO \u662f\u6307\u6570\uff08\u7ffb\u500d\uff09\u4e0a\u6da8\u7684\uff0c\u5f53\u8d85\u8fc7\u6700\u5927\u91cd\u4f20\u6b21\u6570\u540e\uff0c\u5ba2\u6237\u7aef\u4e0d\u518d\u53d1\u9001 SYN\u5305\u3002\u5728 Linux \u4e2d\uff0c\u7b2c\u4e00\u6b21\u63e1\u624b\u7684 SYN \u8d85\u65f6\u91cd\u4f20\u6b21\u6570\uff0c\u662f\u5982\u4e0b\u5185\u6838\u53c2\u6570\u6307\u5b9a\u7684\uff1a<\/p>\n

    $ cat \/proc\/sys\/net\/ipv4\/tcp_syn_retries<\/p>\n

    5<\/p>\n

    tcp_syn_retries \u9ed8\u8ba4\u503c\u4e3a 5\uff0c\u4e5f\u5c31\u662f SYN \u6700\u5927\u91cd\u4f20\u6b21\u6570\u662f 5 \u6b21\u3002<\/p>\n

    \u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u7ee7\u7eed\u505a\u5b9e\u9a8c\uff0c\u628a tcp_syn_retries \u8bbe\u7f6e\u4e3a 2 \u6b21\uff1a<\/p>\n

    $ echo 2 > \/proc\/sys\/net\/ipv4\/tcp_syn_retries<\/p>\n

    \u91cd\u4f20\u6293\u5305\u540e\uff0c\u7528 Wireshark \u6253\u5f00\u5206\u6790\uff0c\u663e\u793a\u5982\u4e0b\u56fe\uff1a<\/p>\n<\/section>\n

    \n
    <\/div><\/section>\n<\/section>\n
    \n

    \n

    \u5b9e\u9a8c\u4e00\u603b\u7ed3<\/strong><\/p>\n

    \u901a\u8fc7\u5b9e\u9a8c\u4e00\u7684\u5b9e\u9a8c\u7ed3\u679c\uff0c\u6211\u4eec\u53ef\u4ee5\u5f97\u77e5\uff0c\u5f53\u5ba2\u6237\u7aef\u53d1\u8d77\u7684 TCP \u7b2c\u4e00\u6b21\u63e1\u624b SYN \u5305\uff0c\u5728\u8d85\u65f6\u65f6\u95f4\u5185\u6ca1\u6536\u5230\u670d\u52a1\u7aef\u7684 ACK\uff0c\u5c31\u4f1a\u5728\u8d85\u65f6\u91cd\u4f20 SYN \u6570\u636e\u5305\uff0c\u6bcf\u6b21\u8d85\u65f6\u91cd\u4f20\u7684 RTO \u662f\u7ffb\u500d\u4e0a\u6da8\u7684\uff0c\u76f4\u5230 SYN \u5305\u7684\u91cd\u4f20\u6b21\u6570\u5230\u8fbe tcp_syn_retries \u503c\u540e\uff0c\u5ba2\u6237\u7aef\u4e0d\u518d\u53d1\u9001 SYN \u5305\u3002<\/p>\n<\/section>\n

    \n
    <\/div><\/section>\n<\/section>\n
    \n

    \n

    \u5b9e\u9a8c\u4e8c\uff1aTCP \u7b2c\u4e8c\u6b21\u63e1\u624b SYN\u3001ACK \u4e22\u5305<\/strong><\/p>\n

    \n

    \u4e3a\u4e86\u6a21\u62df\u5ba2\u6237\u7aef\u6536\u4e0d\u5230\u670d\u52a1\u7aef\u7b2c\u4e8c\u6b21\u63e1\u624b SYN\u3001ACK \u5305\uff0c\u6211\u7684\u505a\u6cd5\u662f\u5728\u5ba2\u6237\u7aef\u52a0\u4e0a\u9632\u706b\u5899\u9650\u5236\uff0c\u76f4\u63a5\u7c97\u66b4\u7684\u628a\u6765\u81ea\u670d\u52a1\u7aef\u7684\u6570\u636e\u90fd\u4e22\u5f03\uff0c\u9632\u706b\u5899\u7684\u914d\u7f6e\u5982\u4e0b\uff1a<\/p>\n<\/section>\n

    \n
    <\/div><\/section>\n<\/section>\n
    \n

    \n

    \u63a5\u7740\uff0c\u5728\u5ba2\u6237\u7aef\u6267\u884c curl \u547d\u4ee4\uff1a<\/p>\n<\/section>\n

    \n
    <\/div><\/section>\n<\/section>\n
    \n

    \n

    \u4ece date \u8fd4\u56de\u7684\u65f6\u95f4\u524d\u540e\uff0c\u53ef\u4ee5\u7b97\u51fa\u5927\u6982 1 \u5206\u949f\u540e\uff0ccurl \u62a5\u9519\u9000\u51fa\u4e86\u3002\u5ba2\u6237\u7aef\u5728\u8fd9\u5176\u95f4\u6293\u53d6\u7684\u6570\u636e\u5305\uff0c\u7528 Wireshark \u6253\u5f00\u5206\u6790\uff0c\u663e\u793a\u7684\u65f6\u5e8f\u56fe\u5982\u4e0b\uff1a<\/p>\n<\/section>\n

    \n
    <\/div><\/section>\n<\/section>\n
    \n

    \n

    \u4ece\u56fe\u4e2d\u53ef\u4ee5\u53d1\u73b0\uff1a\u5ba2\u6237\u7aef\u53d1\u8d77 SYN \u540e\uff0c\u7531\u4e8e\u9632\u706b\u5899\u5c4f\u853d\u4e86\u670d\u52a1\u7aef\u7684\u6240\u6709\u6570\u636e\u5305\uff0c\u6240\u4ee5 curl \u662f\u65e0\u6cd5\u6536\u5230\u670d\u52a1\u7aef\u7684SYN\u3001ACK \u5305\uff0c\u5f53\u53d1\u751f\u8d85\u65f6\u540e\uff0c\u5c31\u4f1a\u91cd\u4f20 SYN \u5305\u3002<\/span><\/p>\n

    \n

    \u670d\u52a1\u7aef\u6536\u5230\u5ba2\u6237\u7684 SYN \u5305\u540e\uff0c\u5c31\u4f1a\u56de SYN\u3001ACK \u5305\uff0c\u4f46\u662f\u5ba2\u6237\u7aef\u4e00\u76f4\u6ca1\u6709\u56de ACK\uff0c\u670d\u52a1\u7aef\u5728\u8d85\u65f6\u540e\uff0c\u91cd\u4f20\u4e86 SYN\u3001ACK \u5305\uff0c\u63a5\u7740\u4e00\u4f1a\uff0c\u5ba2\u6237\u7aef\u8d85\u65f6\u91cd\u4f20\u7684 SYN \u5305\u53c8\u62b5\u8fbe\u4e86\u670d\u52a1\u7aef\uff0c\u670d\u52a1\u7aef\u6536\u5230\u540e\uff0c\u8d85\u65f6\u5b9a\u65f6\u5668\u5c31\u91cd\u65b0\u8ba1\u65f6\uff0c\u7136\u540e\u56de\u4e86 SYN\u3001ACK \u5305\uff0c\u6240\u4ee5\u76f8\u5f53\u4e8e\u670d\u52a1\u7aef\u7684\u8d85\u65f6\u5b9a\u65f6\u5668\u53ea\u89e6\u53d1\u4e86\u4e00\u6b21\uff0c\u53c8\u88ab\u91cd\u7f6e\u4e86\u3002<\/p>\n

    \n

    \u6700\u540e\uff0c\u5ba2\u6237\u7aef SYN \u8d85\u65f6\u91cd\u4f20\u6b21\u6570\u8fbe\u5230\u4e86 5 \u6b21\uff08tcp_syn_retries \u9ed8\u8ba4\u503c 5 \u6b21\uff09\uff0c\u5c31\u4e0d\u518d\u7ee7\u7eed\u53d1\u9001SYN \u5305\u4e86\u3002<\/p>\n

    \n

    \u6240\u4ee5\uff0c\u6211\u4eec\u53ef\u4ee5\u53d1\u73b0\uff0c\u5f53\u7b2c\u4e8c\u6b21\u63e1\u624b\u7684 SYN\u3001ACK \u4e22\u5305\u65f6\uff0c\u5ba2\u6237\u7aef\u4f1a\u8d85\u65f6\u91cd\u53d1 SYN \u5305\uff0c\u670d\u52a1\u7aef\u4e5f\u4f1a\u8d85\u65f6\u91cd\u4f20 SYN\u3001ACK \u5305\u3002\u5ba2\u6237\u7aef\u8bbe\u7f6e\u4e86\u9632\u706b\u5899\uff0c\u5c4f\u853d\u4e86\u670d\u52a1\u7aef\u7684\u7f51\u7edc\u5305\uff0c\u4e3a\u4ec0\u4e48 tcpdump \u8fd8\u80fd\u6293\u5230\u670d\u52a1\u7aef\u7684\u7f51\u7edc\u5305\uff1f\u6dfb\u52a0 iptables \u9650\u5236\u540e\uff0c tcpdump \u662f\u5426\u80fd\u6293\u5230\u5305 \uff0c\u8fd9\u8981\u770b\u6dfb\u52a0\u7684 iptables \u9650\u5236\u6761\u4ef6\uff1a<\/p>\n

      \n
    • \n

      \u5982\u679c\u6dfb\u52a0\u7684\u662f INPUT \u89c4\u5219\uff0c\u5219\u53ef\u4ee5\u6293\u5f97\u5230\u5305<\/p>\n<\/li>\n

    • \n

      \u5982\u679c\u6dfb\u52a0\u7684\u662f OUTPUT \u89c4\u5219\uff0c\u5219\u6293\u4e0d\u5230\u5305<\/p>\n<\/li>\n<\/ul>\n

      \n

      \u7f51\u7edc\u5305\u8fdb\u5165\u4e3b\u673a\u540e\u7684\u987a\u5e8f\u5982\u4e0b\uff1a<\/p>\n

      \u8fdb\u6765\u7684\u987a\u5e8f Wire -> NIC -> tcpdump -> netfilter\/iptables<\/p>\n

      \u51fa\u53bb\u7684\u987a\u5e8f iptables -> tcpdump -> NIC -> Wire<\/p>\n

      \n

      tcp_syn_retries \u662f\u9650\u5236 SYN \u91cd\u4f20\u6b21\u6570\uff0c\u90a3\u7b2c\u4e8c\u6b21\u63e1\u624b SYN\u3001ACK \u9650\u5236\u6700\u5927\u91cd\u4f20\u6b21\u6570\u662f\u591a\u5c11\uff1f<\/p>\n

      \n

      TCP \u7b2c\u4e8c\u6b21\u63e1\u624b SYN\u3001ACK \u5305\u7684\u6700\u5927\u91cd\u4f20\u6b21\u6570\u662f\u901a\u8fc7 tcp_synack_retries \u5185\u6838\u53c2\u6570\u9650\u5236\u7684\uff0c\u5176\u9ed8\u8ba4\u503c\u5982\u4e0b\uff1a<\/p>\n

      $ cat \/proc\/sys\/net\/ipv4\/tcp_synack_retries<\/p>\n

      5<\/p>\n

      \n

      \u662f\u7684\uff0cTCP \u7b2c\u4e8c\u6b21\u63e1\u624b SYN\u3001ACK \u5305\u7684\u6700\u5927\u91cd\u4f20\u6b21\u6570\u9ed8\u8ba4\u503c\u662f 5 \u6b21\u3002<\/p>\n

      \n

      \u4e3a\u4e86\u9a8c\u8bc1 SYN\u3001ACK \u5305\u6700\u5927\u91cd\u4f20\u6b21\u6570\u662f 5 \u6b21\uff0c\u6211\u4eec\u7ee7\u7eed\u505a\u4e0b\u5b9e\u9a8c\uff0c\u6211\u4eec\u5148\u628a\u5ba2\u6237\u7aef\u7684 tcp_syn_retries<\/p>\n

      \n

      \u8bbe\u7f6e\u4e3a 1\uff0c\u8868\u793a\u5ba2\u6237\u7aef SYN \u6700\u5927\u8d85\u65f6\u6b21\u6570\u662f 1 \u6b21\uff0c\u76ee\u7684\u662f\u4e3a\u4e86\u9632\u6b62\u591a\u6b21\u91cd\u4f20 SYN\uff0c\u628a\u670d\u52a1\u7aef SYN\u3001ACK \u8d85\u65f6\u5b9a\u65f6\u5668\u91cd\u7f6e\u3002<\/span><\/p>\n

      \n

      \u63a5\u7740\uff0c\u8fd8\u662f\u5982\u4e0a\u9762\u7684\u6b65\u9aa4\uff1a<\/p>\n

        \n
      • \n

        \u5ba2\u6237\u7aef\u914d\u7f6e\u9632\u706b\u5899\u5c4f\u853d\u670d\u52a1\u7aef\u7684\u6570\u636e\u5305<\/p>\n<\/li>\n

      • \n

        \u5ba2\u6237\u7aef tcpdump \u6293\u53d6 curl \u6267\u884c\u65f6\u7684\u6570\u636e\u5305<\/p>\n<\/li>\n<\/ul>\n

        \n

        \u628a\u6293\u53d6\u7684\u6570\u636e\u5305\uff0c\u7528 Wireshark \u6253\u5f00\u5206\u6790\uff0c\u663e\u793a\u7684\u65f6\u5e8f\u56fe\u5982\u4e0b\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u4ece\u4e0a\u56fe\uff0c\u6211\u4eec\u53ef\u4ee5\u5206\u6790\u51fa\uff1a\u5ba2\u6237\u7aef\u7684 SYN \u53ea\u8d85\u65f6\u91cd\u4f20\u4e86 1 \u6b21\uff0c\u56e0\u4e3a tcp_syn_retries \u503c\u4e3a 1<\/span><\/p>\n

        \n

        \u670d\u52a1\u7aef\u5e94\u7b54\u4e86\u5ba2\u6237\u7aef\u8d85\u65f6\u91cd\u4f20\u7684 SYN \u5305\u540e\uff0c\u7531\u4e8e\u4e00\u76f4\u6536\u4e0d\u5230\u5ba2\u6237\u7aef\u7684 ACK \u5305\uff0c\u6240\u4ee5\u670d\u52a1\u7aef\u4e00\u76f4\u5728\u8d85\u65f6\u91cd\u4f20 SYN\u3001ACK \u5305\uff0c\u6bcf\u6b21\u7684 RTO \u4e5f\u662f\u6307\u6570\u4e0a\u6da8\u7684\uff0c\u4e00\u5171\u8d85\u65f6\u91cd\u4f20\u4e86 5 \u6b21\uff0c\u56e0\u4e3atcp_synack_retries \u503c\u4e3a 5<\/p>\n

        \n

        \u63a5\u7740\uff0c\u6211\u628a tcp_synack_retries \u8bbe\u7f6e\u4e3a 2\uff0c tcp_syn_retries \u4f9d\u7136\u8bbe\u7f6e\u4e3a 1:<\/p>\n

        $ echo 2 > \/proc\/sys\/net\/ipv4\/tcp_synack_retries<\/p>\n

        $ echo 1 > \/proc\/sys\/net\/ipv4\/tcp_syn_retries<\/p>\n

        \n

        \u4f9d\u7136\u4fdd\u6301\u4e00\u6837\u7684\u5b9e\u9a8c\u6b65\u9aa4\u8fdb\u884c\u64cd\u4f5c\uff0c\u63a5\u7740\u628a\u6293\u53d6\u7684\u6570\u636e\u5305\uff0c\u7528 Wireshark \u6253\u5f00\u5206\u6790\uff0c\u663e\u793a\u7684\u65f6\u5e8f\u56fe\u5982\u4e0b\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u7531\u4e0a\u56fe\u53ef\u89c1\uff1a\u5ba2\u6237\u7aef\u7684 SYN \u5305\u53ea\u8d85\u65f6\u91cd\u4f20\u4e86 1 \u6b21\uff0c\u7b26\u5408 tcp_syn_retries \u8bbe\u7f6e\u7684\u503c\uff1b<\/span>\u670d\u52a1\u7aef\u7684 SYN\u3001ACK \u8d85\u65f6\u91cd\u4f20\u4e86 2 \u6b21\uff0c\u7b26\u5408 tcp_synack_retries \u8bbe\u7f6e\u7684\u503c\u3002<\/span><\/p>\n

        \n

        \u5b9e\u9a8c\u4e8c\u603b\u7ed3<\/strong><\/p>\n

        \u901a\u8fc7\u5b9e\u9a8c\u4e8c\u7684\u5b9e\u9a8c\u7ed3\u679c\uff0c\u6211\u4eec\u53ef\u4ee5\u5f97\u77e5\uff0c\u5f53 TCP \u7b2c\u4e8c\u6b21\u63e1\u624b SYN\u3001ACK \u5305\u4e22\u4e86\u540e\uff0c\u5ba2\u6237\u7aef SYN \u5305\u4f1a\u53d1\u751f\u8d85\u65f6\u91cd\u4f20\uff0c\u670d\u52a1\u7aef SYN\u3001ACK \u4e5f\u4f1a\u53d1\u751f\u8d85\u65f6\u91cd\u4f20\u3002\u5ba2\u6237\u7aef SYN \u5305\u8d85\u65f6\u91cd\u4f20\u7684\u6700\u5927\u6b21\u6570\uff0c\u662f\u7531 tcp_syn_retries \u51b3\u5b9a\u7684\uff0c\u9ed8\u8ba4\u503c\u662f 5 \u6b21\uff1b\u670d\u52a1\u7aef SYN\u3001ACK \u5305\u65f6\u91cd\u4f20\u7684\u6700\u5927\u6b21\u6570\uff0c\u662f\u7531 tcp_synack_retries \u51b3\u5b9a\u7684\uff0c\u9ed8\u8ba4\u503c\u662f 5 \u6b21\u3002<\/p>\n

        \n

        \u5b9e\u9a8c\u4e09\uff1aTCP \u7b2c\u4e09\u6b21\u63e1\u624b ACK \u4e22\u5305<\/strong><\/p>\n

        \n

        \u4e3a\u4e86\u6a21\u62df TCP \u7b2c\u4e09\u6b21\u63e1\u624b ACK \u5305\u4e22\uff0c\u6211\u7684\u5b9e\u9a8c\u65b9\u6cd5\u662f\u5728\u670d\u52a1\u7aef\u914d\u7f6e\u9632\u706b\u5899\uff0c\u5c4f\u853d\u5ba2\u6237\u7aef TCP \u62a5\u6587\u4e2d\u6807\u5fd7\u4f4d\u662f ACK \u7684\u5305\uff0c\u4e5f\u5c31\u662f\u5f53\u670d\u52a1\u7aef\u6536\u5230\u5ba2\u6237\u7aef\u7684 TCP ACK \u7684\u62a5\u6587\u65f6\u5c31\u4f1a\u4e22\u5f03\uff0ciptables \u914d\u7f6e\u547d\u4ee4\u5982\u4e0b\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u63a5\u7740\uff0c\u5728\u5ba2\u6237\u7aef\u6267\u884c\u5982\u4e0b tcpdump \u547d\u4ee4\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u7136\u540e\uff0c\u5ba2\u6237\u7aef\u5411\u670d\u52a1\u7aef\u53d1\u8d77 telnet\uff0c\u56e0\u4e3a telnet \u547d\u4ee4\u662f\u4f1a\u53d1\u8d77 TCP \u8fde\u63a5\uff0c\u6240\u4ee5\u7528\u6b64\u547d\u4ee4\u505a\u6d4b\u8bd5\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u6b64\u65f6\uff0c\u7531\u4e8e\u670d\u52a1\u7aef\u6536\u4e0d\u5230\u7b2c\u4e09\u6b21\u63e1\u624b\u7684 ACK \u5305\uff0c\u6240\u4ee5\u4e00\u76f4\u5904\u4e8e SYN_RECV \u72b6\u6001\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u800c\u5ba2\u6237\u7aef\u662f\u5df2\u5b8c\u6210 TCP \u8fde\u63a5\u5efa\u7acb\uff0c\u5904\u4e8e ESTABLISHED \u72b6\u6001\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u8fc7\u4e86 1 \u5206\u949f\u540e\uff0c\u89c2\u5bdf\u53d1\u73b0\u670d\u52a1\u7aef\u7684 TCP \u8fde\u63a5\u4e0d\u89c1\u4e86\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u8fc7\u4e86 30 \u5206\u522b\uff0c\u5ba2\u6237\u7aef\u4f9d\u7136\u8fd8\u662f\u5904\u4e8e ESTABLISHED \u72b6\u6001\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u63a5\u7740\uff0c\u5728\u521a\u624d\u5ba2\u6237\u7aef\u5efa\u7acb\u7684 telnet \u4f1a\u8bdd\uff0c\u8f93\u5165 123456 \u5b57\u7b26\uff0c\u8fdb\u884c\u53d1\u9001\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u6301\u7eed\u300c\u597d\u957f\u300d\u4e00\u6bb5\u65f6\u95f4\uff0c\u5ba2\u6237\u7aef\u7684 telnet \u624d\u65ad\u5f00\u8fde\u63a5\uff1a<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u4ee5\u4e0a\u5c31\u662f\u672c\u6b21\u7684\u5b9e\u73b0\u4e09\u7684\u73b0\u8c61\uff0c\u8fd9\u91cc\u5b58\u5728\u4e24\u4e2a\u7591\u70b9\uff1a<\/p>\n

        \n

        \u4e3a\u4ec0\u4e48\u670d\u52a1\u7aef\u539f\u672c\u5904\u4e8e SYN_RECV \u72b6\u6001\u7684\u8fde\u63a5\uff0c\u8fc7 1 \u5206\u949f\u540e\u5c31\u6d88\u5931\u4e86\uff1f<\/span><\/p>\n

        \n

        \u539f\u56e0\uff1a\u670d\u52a1\u7aef\u5728\u91cd\u4f20 SYN\u3001ACK \u5305\u65f6\uff0c\u8d85\u8fc7\u4e86\u6700\u5927\u91cd\u4f20\u6b21\u6570 tcp_synack_retries \uff0c\u4e8e\u662f\u670d\u52a1\u7aef\u7684 TCP\u8fde\u63a5\u4e3b\u52a8\u65ad\u5f00\u4e86\u3002<\/span><\/p>\n

        \n

        \u4e3a\u4ec0\u4e48\u5ba2\u6237\u7aef telnet \u8f93\u5165 123456 \u5b57\u7b26\u540e\uff0c\u8fc7\u4e86\u597d\u957f\u4e00\u6bb5\u65f6\u95f4\uff0ctelnet \u624d\u65ad\u5f00\u8fde\u63a5\uff1f<\/span><\/p>\n

        \n

        \u539f\u56e0\uff1a\u5ba2\u6237\u7aef\u5411\u670d\u52a1\u7aef\u53d1\u9001\u6570\u636e\u5305\u65f6\uff0c\u7531\u4e8e\u670d\u52a1\u7aef\u7684 TCP \u8fde\u63a5\u5df2\u7ecf\u9000\u51fa\u4e86\uff0c\u6240\u4ee5\u6570\u636e\u5305\u4e00\u76f4\u5728\u8d85\u65f6\u91cd\u4f20\uff0c\u5171\u91cd\u4f20\u4e86 15 \u6b21\uff0c telnet \u5c31\u65ad\u5f00\u4e86\u8fde\u63a5\u3002<\/p>\n<\/section>\n

        \n
        <\/div><\/section>\n<\/section>\n
        \n

        \n

        \u4e0a\u56fe\u7684\u6d41\u7a0b\uff1a\u5ba2\u6237\u7aef\u53d1\u9001 SYN \u5305\u7ed9\u670d\u52a1\u7aef\uff0c\u670d\u52a1\u7aef\u6536\u5230\u540e\uff0c\u56de\u4e86\u4e2a SYN\u3001ACK \u5305\u7ed9\u5ba2\u6237\u7aef\uff0c\u6b64\u65f6\u670d\u52a1\u7aef\u7684TCP \u8fde\u63a5\u5904\u4e8e SYN_RECV \u72b6\u6001\uff1b<\/span><\/p>\n

        \n

        \u5ba2\u6237\u7aef\u6536\u5230\u670d\u52a1\u7aef\u7684 SYN\u3001ACK \u5305\u540e\uff0c\u7ed9\u670d\u52a1\u7aef\u56de\u4e86\u4e2a ACK \u5305\uff0c\u6b64\u65f6\u5ba2\u6237\u7aef\u7684 TCP \u8fde\u63a5\u5904\u4e8eESTABLISHED \u72b6\u6001\uff1b<\/p>\n

        \n

        \u7531\u4e8e\u670d\u52a1\u7aef\u914d\u7f6e\u4e86\u9632\u706b\u5899\uff0c\u5c4f\u853d\u4e86\u5ba2\u6237\u7aef\u7684 ACK \u5305\uff0c\u6240\u4ee5\u670d\u52a1\u7aef\u4e00\u76f4\u5904\u4e8e SYN_RECV \u72b6\u6001\uff0c\u6ca1\u6709\u8fdb\u5165 ESTABLISHED \u72b6\u6001\uff0ctcpdump \u4e4b\u6240\u4ee5\u80fd\u6293\u5230\u5ba2\u6237\u7aef\u7684 ACK \u5305\uff0c\u662f\u56e0\u4e3a\u6570\u636e\u5305\u8fdb\u5165\u7cfb\u7edf\u7684\u987a\u5e8f\u662f\u5148\u8fdb\u5165 tcpudmp\uff0c\u540e\u7ecf\u8fc7 iptables\uff1b<\/p>\n

        \n

        \u63a5\u7740\uff0c\u670d\u52a1\u7aef\u8d85\u65f6\u91cd\u4f20\u4e86 SYN\u3001ACK \u5305\uff0c\u91cd\u4f20\u4e86 5 \u6b21\u540e\uff0c\u4e5f\u5c31\u662f\u8d85\u8fc7 tcp_synack_retries \u7684\u503c\uff08\u9ed8\u8ba4\u503c\u662f 5\uff09\uff0c\u7136\u540e\u5c31\u6ca1\u6709\u7ee7\u7eed\u91cd\u4f20\u4e86\uff0c\u6b64\u65f6\u670d\u52a1\u7aef\u7684 TCP \u8fde\u63a5\u4e3b\u52a8\u4e2d\u6b62\u4e86\uff0c\u6240\u4ee5\u521a\u624d\u5904\u4e8eSYN_RECV \u72b6\u6001\u7684 TCP \u8fde\u63a5\u65ad\u5f00\u4e86\uff0c\u800c\u5ba2\u6237\u7aef\u4f9d\u7136\u5904\u4e8eESTABLISHED \u72b6\u6001\uff1b<\/p>\n

        \n

        \u867d\u7136\u670d\u52a1\u7aef TCP \u65ad\u5f00\u4e86\uff0c\u4f46\u8fc7\u4e86\u4e00\u6bb5\u65f6\u95f4\uff0c\u53d1\u73b0\u5ba2\u6237\u7aef\u4f9d\u7136\u5904\u4e8eESTABLISHED \u72b6\u6001\uff0c\u4e8e\u662f\u5c31\u5728\u5ba2\u6237\u7aef\u7684 telnet \u4f1a\u8bdd\u8f93\u5165\u4e86 123456 \u5b57\u7b26\uff1b<\/p>\n

        \n

        \u6b64\u65f6\u7531\u4e8e\u670d\u52a1\u7aef\u5df2\u7ecf\u65ad\u5f00\u8fde\u63a5\uff0c\u5ba2\u6237\u7aef\u53d1\u9001\u7684\u6570\u636e\u62a5\u6587\uff0c\u4e00\u76f4\u5728\u8d85\u65f6\u91cd\u4f20\uff0c\u6bcf\u4e00\u6b21\u91cd\u4f20\uff0cRTO \u7684\u503c\u662f\u6307\u6570\u589e\u957f\u7684\uff0c\u6240\u4ee5\u6301\u7eed\u4e86\u597d\u957f\u4e00\u6bb5\u65f6\u95f4\uff0c\u5ba2\u6237\u7aef\u7684 telnet \u624d\u62a5\u9519\u9000\u51fa\u4e86\uff0c\u6b64\u65f6\u5171\u91cd\u4f20\u4e86 15\u6b21\u3002<\/p>\n<\/section>\n<\/section>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

        \u7f51\u7edc\u5b9e\u6218\u5de5\u5177\uff1alinux :tcpdump \/ window:Wireshark \u8fd9\u4e24\u8005\u5b9e\u9645\u4e0a\u662f\u642d\u914d\u4f7f\u7528\u7684\uff0c\u5148 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-4213","post","type-post","status-publish","format-standard","hentry","category-linux"],"_links":{"self":[{"href":"https:\/\/www.xh86.me\/index.php?rest_route=\/wp\/v2\/posts\/4213","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xh86.me\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xh86.me\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xh86.me\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xh86.me\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4213"}],"version-history":[{"count":2,"href":"https:\/\/www.xh86.me\/index.php?rest_route=\/wp\/v2\/posts\/4213\/revisions"}],"predecessor-version":[{"id":4215,"href":"https:\/\/www.xh86.me\/index.php?rest_route=\/wp\/v2\/posts\/4213\/revisions\/4215"}],"wp:attachment":[{"href":"https:\/\/www.xh86.me\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4213"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xh86.me\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4213"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xh86.me\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4213"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}