{"id":113,"date":"2026-06-10T15:15:39","date_gmt":"2026-06-10T07:15:39","guid":{"rendered":"https:\/\/zhiyublog.cn\/?p=113"},"modified":"2026-06-10T15:50:32","modified_gmt":"2026-06-10T07:50:32","slug":"tcp%e5%8d%8f%e8%ae%ae","status":"publish","type":"post","link":"https:\/\/zhiyublog.cn\/index.php\/2026\/06\/10\/tcp%e5%8d%8f%e8%ae%ae\/","title":{"rendered":"TCP\u534f\u8bae"},"content":{"rendered":"\n
\"\"<\/div><\/span>
\n

<\/p>\n<\/div><\/div>\n\n\n\n

TCP \u662f\u4e92\u8054\u7f51\u57fa\u77f3\uff0cHTTP\u3001HTTPS\u3001MySQL\u3001Redis\u3001SSH \u5168\u90e8\u57fa\u4e8e TCP\u3002\u5f88\u591a\u5f00\u53d1\u8005\u53ea\u4f1a\u80cc\u201c\u4e09\u6b21\u63e1\u624b\u3001\u56db\u6b21\u6325\u624b\u201d\uff0c\u4f46\u4e0d\u61c2\u4e3a\u4ec0\u4e48\u8fd9\u4e48\u8bbe\u8ba1\u3001\u5e8f\u53f7\u600e\u4e48\u6da8\u3001\u7a97\u53e3\u5e72\u561b\u7528\u3001\u6807\u5fd7\u4f4d\u533a\u522b\u3001\u6d41\u91cf\u4e0e\u62e5\u585e\u63a7\u5236\u7684\u5dee\u5f02<\/strong>\u3002<\/p>\n\n\n\n

\u672c\u6587\u662f\u4e00\u5957\u4ece\u96f6\u5230\u7cbe\u901a\u7684 TCP \u5b8c\u6574\u4f53\u7cfb<\/strong>\uff0c\u5185\u5bb9\u7406\u89e3\u6765\u81ea\u7f51\u7edc\u53ca\u4e2a\u4eba\u5b66\u4e60<\/p>\n\n\n\n

\u4e00\u3001TCP \u662f\u4ec0\u4e48\uff1f\u6838\u5fc3\u7279\u6027\u603b\u89c8<\/h2>\n\n\n\n

TCP\uff08Transmission Control Protocol\uff0c\u4f20\u8f93\u63a7\u5236\u534f\u8bae\uff09\u662f\u9762\u5411\u8fde\u63a5\u3001\u53ef\u9760\u3001\u5168\u53cc\u5de5\u3001\u57fa\u4e8e\u5b57\u8282\u6d41<\/strong>\u7684\u4f20\u8f93\u5c42\u534f\u8bae\u3002<\/p>\n\n\n\n

\u56db\u5927\u6838\u5fc3\u80fd\u529b\uff0c\u4e5f\u662f TCP \u533a\u522b\u4e8e UDP \u7684\u672c\u8d28\uff1a<\/p>\n\n\n\n

    \n
  • \u9762\u5411\u8fde\u63a5<\/strong>\uff1a\u4f20\u8f93\u524d\u5fc5\u987b\u63e1\u624b\u5efa\u7acb\u8fde\u63a5\uff0c\u4f20\u8f93\u540e\u6325\u624b\u91ca\u653e\u8fde\u63a5<\/li>\n\n\n\n
  • \u53ef\u9760\u4f20\u8f93<\/strong>\uff1a\u4fdd\u8bc1\u6570\u636e\u4e0d\u4e22\u3001\u4e0d\u91cd\u3001\u4e0d\u4e71<\/li>\n\n\n\n
  • \u6d41\u91cf\u63a7\u5236<\/strong>\uff1a\u89e3\u51b3\u300c\u53d1\u9001\u592a\u5feb\u3001\u63a5\u6536\u5904\u7406\u4e0d\u8fc7\u6765\u300d\u7684\u95ee\u9898<\/li>\n\n\n\n
  • \u62e5\u585e\u63a7\u5236<\/strong>\uff1a\u89e3\u51b3\u300c\u7f51\u7edc\u94fe\u8def\u62e5\u5835\u3001\u4e22\u5305\u8d85\u65f6\u300d\u7684\u95ee\u9898<\/li>\n<\/ul>\n\n\n\n

    UDP \u662f\u201c\u53ea\u7ba1\u53d1\u3001\u4e0d\u7ba1\u5230\u201d\uff0cTCP \u662f\u201c\u53d1\u4e00\u6b65\u3001\u786e\u8ba4\u4e00\u6b65\u3001\u5168\u7a0b\u53ef\u63a7\u201d\u3002<\/p>\n\n\n\n

    \u4e8c\u3001TCP \u62a5\u6587\u5934\u6838\u5fc3\u5b57\u6bb5<\/h2>\n\n\n\n
    \"\"<\/div><\/figure>\n\n\n\n

    TCP \u6240\u6709\u7684\u63e1\u624b\u3001\u6325\u624b\u3001\u53ef\u9760\u4f20\u8f93\u3001\u63a7\u901f\u903b\u8f91\uff0c\u5168\u90e8\u6765\u81ea\u62a5\u6587\u5934\u5b57\u6bb5\uff0c\u53ea\u9700\u638c\u63e17\u4e2a\u6838\u5fc3\u8981\u7d20<\/strong>\uff1a<\/p>\n\n\n\n

    1. SEQ \u5e8f\u5217\u53f7\uff0832\u4f4d\uff09<\/h3>\n\n\n\n

    \u4f5c\u7528\uff1a\u7ed9\u6bcf\u4e00\u4e2a\u4f20\u8f93\u5b57\u8282\u7f16\u53f7<\/strong><\/p>\n\n\n\n

    \u6838\u5fc3\u4ef7\u503c\uff1a\u6392\u5e8f\u3001\u53bb\u91cd\u3001\u91cd\u4f20\u5b9a\u4f4d\u3002<\/p>\n\n\n\n

    \u89c4\u5219\uff1a<\/p>\n\n\n\n

      \n
    • \u8fde\u63a5\u5efa\u7acb\u65f6\u751f\u6210 ISN \u521d\u59cb\u5e8f\u5217\u53f7<\/strong>\uff08\u57fa\u4e8e\u65f6\u949f\u3001\u6bcf4ms+1\uff0c\u9632\u65e7\u62a5\u6587\u5e72\u6270\uff09<\/li>\n\n\n\n
    • \u6570\u636e\u4f20\u8f93\u9636\u6bb5\uff1aSEQ \u53ea\u6309\u5b57\u8282\u7d2f\u52a0\uff0c\u548c\u65f6\u95f4\u65e0\u5173<\/strong><\/li>\n\n\n\n
    • \u672a\u6536\u5230 ACK \u5219\u4e00\u76f4\u91cd\u4f20\u76f8\u540c SEQ<\/strong>\uff0c\u4e0d\u66f4\u65b0\u5e8f\u53f7<\/li>\n\n\n\n
    • SYN\u3001FIN \u5404\u5360\u7528 1 \u4e2a\u5e8f\u5217\u53f7<\/strong>\uff08\u65e0\u6570\u636e\u4f46\u5360\u53f7\uff09<\/li>\n<\/ul>\n\n\n\n

      2. ACK \u786e\u8ba4\u53f7\uff0832\u4f4d\uff09<\/h3>\n\n\n\n

      \u4f5c\u7528\uff1a\u544a\u8bc9\u5bf9\u65b9\u201c\u6211\u6536\u5230\u54ea\u4e86\u201d<\/strong><\/p>\n\n\n\n

      \u516c\u5f0f\u6052\u6210\u7acb\uff1aACK = \u5bf9\u65b9\u4e0a\u4e00\u6b21 SEQ + \u5df2\u63a5\u6536\u5b57\u8282\u6570<\/strong><\/p>\n\n\n\n

      \u53ea\u8981\u6536\u5230\u5408\u6cd5 ACK\uff0c\u4ee3\u8868\u5bf9\u5e94\u6570\u636e\u5f7b\u5e95\u786e\u8ba4\u6210\u529f\uff0c\u53d1\u9001\u65b9\u53ef\u4ee5\u6ed1\u52a8\u7a97\u53e3\u3001\u53d1\u9001\u65b0\u6570\u636e\u3002<\/p>\n\n\n\n

      \u5f7c\u6b64\u540e\u7eed\u5f00\u59cb\u4f20\u8f93\u6570\u636e\u65f6\u5019\u7684\u4e03\u70b9\u5373\u4e3a\u53d1\u9001\u65f6\u751f\u6210\u7684ISN+1<\/p>\n\n\n\n

      3. Window \u7a97\u53e3\uff0816\u4f4d\uff09<\/h3>\n\n\n\n

      \u4f5c\u7528\uff1a\u6d41\u91cf\u63a7\u5236\u6838\u5fc3<\/strong><\/p>\n\n\n\n

      \u542b\u4e49\uff1a\u5f53\u524d\u4e3b\u673a\u7684\u63a5\u6536\u7f13\u51b2\u533a\u5269\u4f59\u5bb9\u91cf<\/strong>\uff0c\u5355\u4f4d\u5b57\u8282\u3002\u7528\u4e8e\u544a\u8bc9\u53d1\u9001\u65b9\uff1a\u4f60\u6700\u591a\u8fd8\u80fd\u53d1\u591a\u5c11\u6570\u636e\u3002<\/p>\n\n\n\n

      \u903b\u8f91\uff1a<\/p>\n\n\n\n

        \n
      • \u5e94\u7528\u8bfb\u5f97\u5feb \u2192 \u7f13\u51b2\u533a\u7a7a \u2192 \u7a97\u53e3\u53d8\u5927 \u2192 \u53d1\u9001\u63d0\u901f<\/li>\n\n\n\n
      • \u5e94\u7528\u8bfb\u5f97\u6162 \u2192 \u7f13\u51b2\u533a\u6ee1 \u2192 \u7a97\u53e3\u53d8\u5c0f \u2192 \u53d1\u9001\u964d\u901f<\/li>\n\n\n\n
      • \u7a97\u53e3=0 \u2192 \u6682\u505c\u53d1\u9001\u666e\u901a\u6570\u636e<\/li>\n<\/ul>\n\n\n\n

        \u901a\u8fc7\u7a97\u53e3\u7684\u5927\u5c0f\u6765\u5b9e\u65f6\u8c03\u8bd5\u4f20\u8f93\u901f\u7387\uff0c\u63a7\u5236\u6d41\u91cf\u3002<\/p>\n\n\n\n

        4. \u516d\u5927\u6807\u5fd7\u4f4d<\/h3>\n\n\n\n
          \n
        • SYN<\/strong>\uff1a\u5efa\u7acb\u8fde\u63a5<\/li>\n\n\n\n
        • FIN<\/strong>\uff1a\u5173\u95ed\u8fde\u63a5<\/li>\n\n\n\n
        • ACK<\/strong>\uff1a\u786e\u8ba4\u62a5\u6587\uff08\u51e0\u4e4e\u6240\u6709\u4f20\u8f93\u62a5\u6587\u90fd\u5e26ACK\uff09<\/li>\n\n\n\n
        • RST<\/strong>\uff1a\u5f3a\u5236\u91cd\u7f6e\u8fde\u63a5<\/li>\n\n\n\n
        • PSH<\/strong>\uff1a\u63a8\u9001\u4f4d\uff0c\u7acb\u5373\u4ea4\u4ed8\u6570\u636e<\/li>\n\n\n\n
        • URG<\/strong>\uff1a\u7d27\u6025\u4f4d\uff0c\u5e26\u5916\u63d2\u961f\u6570\u636e<\/li>\n<\/ul>\n\n\n\n

          SYN\uff1a<\/strong><\/p>\n\n\n\n

          SYN\u6307\u7684\u5728\u8fde\u63a5\u5efa\u7acb\u65f6\u7528\u6765\u540c\u6b65\u5e8f\u53f7\u3002\u5f53SYN=1\u800cACK=0\u65f6\uff0c\u8868\u660e\u8fd9\u662f\u4e00\u4e2a\u8fde\u63a5\u8bf7\u6c42\u62a5\u6587\u3002\u5bf9\u65b9\u82e5\u540c\u610f\u5efa\u7acb\u8fde\u63a5\uff0c\u5219\u5e94\u5728\u54cd\u5e94\u62a5\u6587\u4e2d\u4f7fSYN=1\u548cACK=1\u3002 \u7efc\u5408\u4e00\u4e0b\uff0cSYN\u7f6e1\u5c31\u8868\u793a\u8fd9\u662f\u4e00\u4e2a\u8fde\u63a5\u8bf7\u6c42\u6216\u8fde\u63a5\u63a5\u53d7\u62a5\u6587\u3002<\/p>\n\n\n\n

          ACK:<\/strong><\/p>\n\n\n\n

          TCP\u5b9e\u73b0\u53ef\u9760\u4f20\u8f93\u7684\u6838\u5fc3\u673a\u5236\u4e4b\u4e00\uff0c\u8d2f\u7a7f\u8fde\u63a5\u5efa\u7acb\u3001\u6570\u636e\u4f20\u8f93\u548c\u8fde\u63a5\u91ca\u653e\u7684\u5168\u8fc7\u7a0b\uff0c\u786e\u4fdd\u6570\u636e\u6309\u5e8f\u3001\u65e0\u4e22\u5931\u5730\u9001\u8fbe\u3002\u82e5ACK=0\uff0c\u5219\u62a5\u6587\u4e0d\u643a\u5e26\u786e\u8ba4\u4fe1\u606f\uff0c\u5f53ACK=1\u65f6\uff0c\u5373\u5e26\u6709\u4e00\u4e2a\u5bf9\u5df2\u88ab\u6210\u529f\u63a5\u6536\u62a5\u6587\u6bb5\u7684\u786e\u8ba4\u5e8f\u53f7\uff0c\u8fd9\u4e2a\u5e8f\u5217\u53f7\u4e5f\u662f\u4e0b\u6b21\u63a5\u6536\u65f6\u671f\u671b\u7684\u6570\u636e\u5f00\u59cb\u4f4d\u7f6e\u3002<\/p>\n\n\n\n

          FIN\uff1a<\/strong><\/p>\n\n\n\n

          \u7528\u4e8e\u5728\u91ca\u653eTCP\u8fde\u63a5\u65f6\uff0c\u6807\u8bc6\u53d1\u9001\u65b9\u6bd4\u7279\u6d41\u7ed3\u675f\uff0c\u7528\u6765\u91ca\u653e\u4e00\u4e2a\u8fde\u63a5\u3002\u5f53 FIN = 1\u65f6\uff0c\u8868\u660e\u6b64\u62a5\u6587\u7684\u53d1\u9001\u65b9\u7684\u6570\u636e\u5df2\u7ecf\u53d1\u9001\u5b8c\u6bd5\uff0c\u5e76\u8981\u6c42\u91ca\u653e\u8fde\u63a5\u3002<\/p>\n\n\n\n

          PSH <\/strong>\uff1a<\/p>\n\n\n\n

          TCP \u9ed8\u8ba4\u4f1a\u300c\u6512\u5305\u5408\u5e76\u3001\u8d85\u65f6\u4ea4\u4ed8\u300d\u63d0\u5347\u6548\u7387\u3002\u5373\u6570\u636e\u4f1a\u5728\u7f13\u5b58\u533a\u7b49\u5f85\u4e0a\u4f20\uff0c\u4e00\u822c\u662f\u662f\u5408\u5e76\u6570\u636e\u540e\u4e00\u5e76\u4e0a\u4f20\u6216\u662f\u6839\u636e\u8bbe\u8ba1\u597d\u7684\u8d85\u65f6\u65f6\u95f4\uff0c\u65f6\u95f4\u5230\u4e86\u5373\u4e0a\u4f20\u3002<\/p>\n\n\n\n

          PSH=1 \u8868\u793a\uff1a\u4e0d\u8981\u6512\u5305\u3001\u4e0d\u8981\u7b49\u5f85\uff0c\u628a\u7f13\u51b2\u533a\u6240\u6709\u6709\u5e8f\u6570\u636e\u7acb\u523b\u4ea4\u7ed9\u5e94\u7528\u5c42<\/strong>\u3002\u5373\u5728\u6536\u5230psh=1\u7684\u62a5\u6587\u65f6\uff0c\u5c06\u7f13\u5b58\u53bb\u73b0\u6709\u7684\u6709\u5e8f\u7684\u6570\u636e\u548c\u62a5\u6587\u5e26\u6709\u7684\u6570\u636e\u76f4\u63a5\u4e0a\u4f20\u63d0\u4ea4\u7ed9\u5e94\u7528\u5c42\u3002<\/p>\n\n\n\n

          \u53d7\u7a97\u53e3\u9650\u5236\u3001\u6709\u5e8f\u3001\u666e\u901a\u6570\u636e\u901a\u9053\u3002<\/p>\n\n\n\n

          URG <\/strong>\uff1a<\/p>\n\n\n\n

          URG=1 \u914d\u5408\u7d27\u6025\u6307\u9488\uff0c\u6807\u8bb0\u7d27\u6025\u5e26\u5916\u6570\u636e<\/strong>\u3002<\/p>\n\n\n\n

          \u7279\u70b9\uff1a\u7a97\u53e3\u4e3a0\u4e5f\u80fd\u53d1\u3001\u4f18\u5148\u5904\u7406\u3001\u4e0d\u8d70\u666e\u901a\u7f13\u51b2\u533a\u961f\u5217\u3001\u5e94\u7528\u9700\u5355\u72ec\u8bfb\u53d6<\/strong>\uff0c\u7528\u4e8e\u4e2d\u65ad\u3001\u7d27\u6025\u6307\u4ee4\u3002\u76f4\u63a5\u6839\u636e\u7d27\u6025\u6307\u9488\u6240\u6307\u5c06\u6570\u636e\u63d0\u4ea4\u7ed9\u5e94\u7528\u5c42\u3002<\/p>\n\n\n\n

          5. MSS \u6700\u5927\u62a5\u6587\u6bb5\u957f\u5ea6<\/h3>\n\n\n\n

          \u63e1\u624b\u9636\u6bb5\u534f\u5546\uff0c\u544a\u77e5\u5bf9\u65b9\u81ea\u5df1\u5355\u6b21\u80fd\u63a5\u6536\u7684\u6700\u5927\u6570\u636e\u957f\u5ea6\uff0c\u907f\u514d\u5206\u7247\uff0c\u63d0\u5347\u4f20\u8f93\u6548\u7387\u3002<\/p>\n\n\n\n

          \u4e09\u3001\u4e09\u6b21\u63e1\u624b\uff1a\u4e3a\u4ec0\u4e48\u4e09\u6b21\uff1f\u5b8c\u6574\u6d41\u7a0b+\u5e8f\u53f7\u89c4\u5219<\/h2>\n\n\n\n

          \u76ee\u7684\uff1a\u53cc\u5411\u786e\u8ba4\u6536\u53d1\u80fd\u529b\u6b63\u5e38<\/strong>\uff08\u5ba2\u6237\u7aef\u80fd\u53d1\u80fd\u6536\u3001\u670d\u52a1\u7aef\u80fd\u53d1\u80fd\u6536\uff09\u3002<\/p>\n\n\n\n

          TCP \u662f\u5168\u53cc\u5de5\uff0c\u9700\u8981\u786e\u8ba4\u4e24\u4e2a\u65b9\u5411\u901a\u9053<\/strong>\u90fd\u53ef\u7528\u3002<\/p>\n\n\n\n

          1. \u7b2c\u4e00\u6b21\u63e1\u624b\uff08C\u2192S\uff09<\/h3>\n\n\n\n

          \u5ba2\u6237\u7aef\u53d1\u9001 SYN=1\uff0cSEQ=C_ISN<\/strong><\/p>\n\n\n\n

          \u72b6\u6001\uff1aSYN_SENT<\/p>\n\n\n\n

          \u542b\u4e49\uff1a\u5ba2\u6237\u7aef\u8bf7\u6c42\u5efa\u7acb\u8fde\u63a5\uff0c\u540c\u6b65\u521d\u59cb\u5e8f\u53f7\u3002<\/p>\n\n\n\n

          2. \u7b2c\u4e8c\u6b21\u63e1\u624b\uff08S\u2192C\uff09<\/h3>\n\n\n\n

          \u670d\u52a1\u7aef\u8fd4\u56de SYN=1\uff0cACK=1\uff0cSEQ=S_ISN\uff0cACK=C_ISN+1<\/strong><\/p>\n\n\n\n

          \u72b6\u6001\uff1aSYN_RCVD<\/p>\n\n\n\n

          \u542b\u4e49\uff1a\u670d\u52a1\u7aef\u6536\u5230\u5ba2\u6237\u7aef\u8bf7\u6c42\uff0c\u540c\u65f6\u540c\u6b65\u81ea\u5df1\u7684\u521d\u59cb\u5e8f\u53f7\u3002<\/p>\n\n\n\n

          3. \u7b2c\u4e09\u6b21\u63e1\u624b\uff08C\u2192S\uff09<\/h3>\n\n\n\n

          \u5ba2\u6237\u7aef\u53d1\u9001 ACK=1\uff0cACK=S_ISN+1<\/strong><\/p>\n\n\n\n

          \u53cc\u65b9\u72b6\u6001\u53d8\u4e3a\uff1aESTABLISHED\uff08\u8fde\u63a5\u5efa\u7acb\uff09<\/p>\n\n\n\n

          \u5173\u952e\u7ed3\u8bba<\/h3>\n\n\n\n
            \n
          • SYN \u5360\u7528\u5e8f\u5217\u53f7\uff0c\u6240\u4ee5 ACK \u5fc5\u987b +1<\/li>\n\n\n\n
          • \u4e1a\u52a1\u6570\u636e\u8d77\u70b9\uff1a\u5ba2\u6237\u7aef\u4ece C_ISN+1 \u5f00\u59cb\uff0c\u670d\u52a1\u7aef\u4ece S_ISN+1 \u5f00\u59cb<\/strong><\/li>\n\n\n\n
          • \u4e3a\u4ec0\u4e48\u4e0d\u662f\u4e24\u6b21\uff1f\u4e24\u6b21\u53ea\u80fd\u8bc1\u660e\u300c\u5ba2\u6237\u7aef\u80fd\u53d1\u3001\u670d\u52a1\u7aef\u80fd\u6536\u300d\uff0c\u65e0\u6cd5\u9a8c\u8bc1\u300c\u670d\u52a1\u7aef\u80fd\u53d1\u3001\u5ba2\u6237\u7aef\u80fd\u6536\u300d<\/li>\n\n\n\n
          • \u4e3a\u4ec0\u4e48\u4e0d\u662f\u56db\u6b21\uff1fSYN+ACK \u53ef\u4ee5\u5408\u5e76\uff0c\u65e0\u9700\u591a\u4f59\u4e00\u6b21<\/li>\n<\/ul>\n\n\n\n

            \u56db\u3001\u56db\u6b21\u6325\u624b\uff1a\u4e3a\u4ec0\u4e48\u56db\u6b21\uff1f\u534a\u5173\u95ed\u539f\u7406+TIME_WAIT<\/h2>\n\n\n\n

            TCP \u5168\u53cc\u5de5\u901a\u9053\uff0c\u8bfb\u5199\u901a\u9053\u72ec\u7acb\u5173\u95ed<\/strong>\uff0c\u56e0\u6b64\u65e0\u6cd5\u50cf\u63e1\u624b\u4e00\u6837\u5408\u5e76\uff0c\u5fc5\u987b\u56db\u6b21\u3002<\/p>\n\n\n\n

            \u6838\u5fc3\u89c4\u5219\uff1aFIN \u540c\u6837\u5360\u7528\u4e00\u4e2a\u5e8f\u5217\u53f7<\/strong>\u3002<\/p>\n\n\n\n

            1. \u7b2c\u4e00\u6b21\u6325\u624b\uff08\u4e3b\u52a8\u7aef\u2192\u88ab\u52a8\u7aef\uff09<\/h3>\n\n\n\n

            \u4e3b\u52a8\u7aef\u53d1\u9001 FIN=1\uff0cSEQ=x<\/strong>\uff0c\u72b6\u6001\uff1aFIN_WAIT_1<\/p>\n\n\n\n

            \u542b\u4e49\uff1a\u6211\u4e0d\u518d\u53d1\u65b0\u6570\u636e\uff0c\u8bf7\u6c42\u5173\u95ed\u53d1\u9001\u901a\u9053\u3002<\/p>\n\n\n\n

            2. \u7b2c\u4e8c\u6b21\u6325\u624b\uff08\u88ab\u52a8\u7aef\u2192\u4e3b\u52a8\u7aef\uff09<\/h3>\n\n\n\n

            \u88ab\u52a8\u7aef\u56de\u590d ACK=1\uff0cACK=x+1<\/strong>\uff0c\u72b6\u6001\uff1aCLOSE_WAIT<\/p>\n\n\n\n

            \u4e3b\u52a8\u7aef\u8fdb\u5165 FIN_WAIT_2<\/p>\n\n\n\n

            \u6b64\u65f6\u8fdb\u5165\u534a\u5173\u95ed\u72b6\u6001<\/strong>\uff1a\u4e3b\u52a8\u7aef\u53ea\u6536\u4e0d\u53d1\uff0c\u88ab\u52a8\u7aef\u53ef\u7ee7\u7eed\u53d1\u5269\u4f59\u6570\u636e\u3002<\/p>\n\n\n\n

            3. \u7b2c\u4e09\u6b21\u6325\u624b\uff08\u88ab\u52a8\u7aef\u2192\u4e3b\u52a8\u7aef\uff09<\/h3>\n\n\n\n

            \u88ab\u52a8\u7aef\u6570\u636e\u53d1\u5b8c\uff0c\u53d1\u9001 FIN=1\uff0cSEQ=y<\/strong>\uff0c\u72b6\u6001\uff1aLAST_ACK<\/p>\n\n\n\n

            \u542b\u4e49\uff1a\u6211\u4e5f\u6ca1\u6570\u636e\u4e86\uff0c\u5f7b\u5e95\u5173\u95ed\u901a\u9053\u3002<\/p>\n\n\n\n

            4. \u7b2c\u56db\u6b21\u6325\u624b\uff08\u4e3b\u52a8\u7aef\u2192\u88ab\u52a8\u7aef\uff09<\/h3>\n\n\n\n

            \u4e3b\u52a8\u7aef\u56de\u590d ACK=1\uff0cACK=y+1<\/strong><\/p>\n\n\n\n

            \u88ab\u52a8\u7aef\u6536\u5230\u7acb\u523b\u53d8\u4e3a CLOSED\u3002<\/p>\n\n\n\n

            \u4e3b\u52a8\u7aef\u8fdb\u5165 TIME_WAIT\uff082MSL\uff09<\/strong>\uff0c\u8d85\u65f6\u540e\u5f7b\u5e95\u5173\u95ed\u3002<\/p>\n\n\n\n

            TIME_WAIT \u4e24\u5927\u6838\u5fc3\u4f5c\u7528<\/h3>\n\n\n\n
              \n
            • \u4fdd\u8bc1\u6700\u540e\u4e00\u6b21 ACK \u53ef\u9760\u5230\u8fbe\uff0c\u907f\u514d\u5bf9\u65b9\u91cd\u4f20 FIN<\/li>\n\n\n\n
            • \u7b49\u5f85\u7f51\u7edc\u6b8b\u7559\u65e7\u62a5\u6587\u5f7b\u5e95\u5931\u6548\uff0c\u9632\u6b62\u65b0\u8fde\u63a5\u88ab\u65e7\u6570\u636e\u5e72\u6270<\/li>\n<\/ul>\n\n\n\n

              \u4e94\u3001\u6d41\u91cf\u63a7\u5236 vs \u62e5\u585e\u63a7\u5236<\/h2>\n\n\n\n

              1. \u6d41\u91cf\u63a7\u5236\uff08Flow Control\uff09<\/h3>\n\n\n\n

              \u9488\u5bf9\u7aef\u4e0e\u7aef<\/strong>\uff1a\u89e3\u51b3\u300c\u63a5\u6536\u65b9\u5e94\u7528\u8bfb\u5f97\u6162\u3001\u7f13\u51b2\u533a\u6ee1\u300d\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n

              \u4f9d\u9760 Window \u63a5\u6536\u7a97\u53e3<\/strong> \u5b9e\u73b0\uff0c\u7531\u63a5\u6536\u65b9\u4e3b\u52a8\u544a\u77e5\u53d1\u9001\u65b9\u9650\u901f\u3002<\/p>\n\n\n\n

              2. \u62e5\u585e\u63a7\u5236\uff08Congestion Control\uff09<\/h3>\n\n\n\n

              \u9488\u5bf9\u7f51\u7edc\u94fe\u8def<\/strong>\uff1a\u89e3\u51b3\u300c\u4e2d\u95f4\u8def\u7531\u62e5\u5835\u3001\u94fe\u8def\u4e22\u5305\u300d\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n

              \u4f9d\u9760 \u62e5\u585e\u7a97\u53e3 cwnd<\/strong> \u5b9e\u73b0\uff0c\u53d1\u9001\u65b9\u81ea\u5df1\u63a2\u6d4b\u7f51\u7edc\u72b6\u6001\u3001\u4e3b\u52a8\u964d\u901f\u3002<\/p>\n\n\n\n

              3. \u53d1\u9001\u901f\u7387\u6700\u7ec8\u516c\u5f0f<\/h3>\n\n\n\n

              \u53ef\u53d1\u9001\u6570\u636e\u91cf = min(\u63a5\u6536\u7a97\u53e3rwnd, \u62e5\u585e\u7a97\u53e3cwnd)<\/strong><\/p>\n\n\n\n

              \u56db\u5927\u62e5\u585e\u7b97\u6cd5\u9636\u6bb5<\/h3>\n\n\n\n
                \n
              • \u6162\u542f\u52a8<\/strong>\uff1a\u6307\u6570\u589e\u957f\uff0c\u5feb\u901f\u63a2\u6d4b\u7f51\u7edc\u5bb9\u91cf<\/li>\n\n\n\n
              • \u62e5\u585e\u907f\u514d<\/strong>\uff1a\u7ebf\u6027\u589e\u957f\uff0c\u5e73\u7a33\u4f20\u8f93<\/li>\n\n\n\n
              • \u5feb\u91cd\u4f20<\/strong>\uff1a\u8fde\u7eed3\u6b21\u5197\u4f59ACK\uff0c\u7acb\u523b\u91cd\u4f20\uff0c\u4e0d\u7b49\u5f85\u8d85\u65f6<\/li>\n\n\n\n
              • \u5feb\u6062\u590d<\/strong>\uff1a\u4e22\u5305\u540e\u4e0d\u56de\u5230\u521d\u59cb\u6700\u5c0f\u503c\uff0c\u964d\u4f4e\u51cf\u901f\u5e45\u5ea6<\/li>\n<\/ul>\n\n\n\n

                \u516d\u3001TCP \u7c98\u5305\u4e0e\u62c6\u5305<\/h2>\n\n\n\n

                TCP \u662f\u5b57\u8282\u6d41\u534f\u8bae<\/strong>\uff0c\u65e0\u62a5\u6587\u8fb9\u754c\uff0c\u64cd\u4f5c\u7cfb\u7edf\u4f1a\u81ea\u52a8\u5408\u5e76\u3001\u62c6\u5206\u6570\u636e\uff0c\u5bfc\u81f4\u7c98\u5305\u62c6\u5305\u3002<\/p>\n\n\n\n

                \u4ea7\u751f\u539f\u56e0<\/h3>\n\n\n\n
                  \n
                • \u53d1\u9001\u65b9\u7f13\u51b2\u533a\u6512\u5305\u5408\u5e76\uff08Nagle \u7b97\u6cd5\uff09<\/li>\n\n\n\n
                • \u63a5\u6536\u65b9\u7f13\u51b2\u533a\u591a\u6b21\u6570\u636e\u5408\u5e76\u8bfb\u53d6<\/li>\n\n\n\n
                • \u5927\u6570\u636e\u88ab MSS \u62c6\u5206\u4f20\u8f93<\/li>\n<\/ul>\n\n\n\n

                  \u89e3\u51b3\u65b9\u6848<\/h3>\n\n\n\n
                    \n
                  • \u56fa\u5b9a\u62a5\u6587\u957f\u5ea6<\/li>\n\n\n\n
                  • \u62a5\u6587\u9996\u5c3e\u5206\u9694\u7b26<\/li>\n\n\n\n
                  • \u957f\u5ea6\u5934+\u6570\u636e\u4f53<\/strong>\uff08\u5de5\u4e1a\u6700\u5e38\u7528\uff09<\/li>\n<\/ul>\n\n\n\n

                    \u4e03\u3001TCP \u6838\u5fc3\u9762\u8bd5\u95ee\u7b54<\/h2>\n\n\n\n

                    1. \u4e3a\u4ec0\u4e48\u4e09\u6b21\u63e1\u624b\u3001\u56db\u6b21\u6325\u624b\uff1f<\/h3>\n\n\n\n

                    \u63e1\u624b\uff1aSYN+ACK \u53ef\u5408\u5e76\uff0c\u53cc\u5411\u786e\u8ba4\u6536\u53d1\u6b63\u5e38\uff1b\u6325\u624b\uff1a\u8bfb\u5199\u901a\u9053\u72ec\u7acb\u5173\u95ed\uff0c\u4e2d\u95f4\u53ef\u80fd\u6b8b\u7559\u6570\u636e\uff0c\u65e0\u6cd5\u5408\u5e76\u3002<\/p>\n\n\n\n

                    2. SEQ \u4ec0\u4e48\u65f6\u5019\u6309\u65f6\u95f4\u3001\u4ec0\u4e48\u65f6\u5019\u6309\u5b57\u8282\uff1f<\/h3>\n\n\n\n

                    \u4ec5 ISN \u521d\u59cb\u5e8f\u53f7\u57fa\u4e8e4ms\u65f6\u949f\u81ea\u589e\uff1b\u8fde\u63a5\u5efa\u7acb\u540e\u5168\u90e8\u6309\u5b57\u8282\u7d2f\u52a0<\/strong>\uff0c\u91cd\u4f20\u5e8f\u53f7\u4e0d\u53d8\u3002<\/p>\n\n\n\n

                    3. PSH \u548c URG \u533a\u522b\uff1f<\/h3>\n\n\n\n

                    PSH\uff1a\u666e\u901a\u6570\u636e\u3001\u7acb\u5373\u4ea4\u4ed8\u3001\u53d7\u7a97\u53e3\u9650\u5236\uff1bURG\uff1a\u7d27\u6025\u5e26\u5916\u6570\u636e\u3001\u7a97\u53e3\u4e3a0\u4e5f\u53ef\u53d1\u9001\u3001\u4f18\u5148\u63d2\u961f\u5904\u7406\u3002<\/p>\n\n\n\n

                    4. \u6d41\u91cf\u63a7\u5236\u548c\u62e5\u585e\u63a7\u5236\u533a\u522b\uff1f<\/h3>\n\n\n\n

                    \u6d41\u91cf\u63a7\u5236\u7ba1\u300c\u63a5\u6536\u65b9\u80fd\u4e0d\u80fd\u625b\u4f4f\u300d\uff0c\u62e5\u585e\u63a7\u5236\u7ba1\u300c\u7f51\u7edc\u94fe\u8def\u80fd\u4e0d\u80fd\u625b\u4f4f\u300d\u3002<\/p>\n\n\n\n

                    5. \u4e3a\u4ec0\u4e48\u9700\u8981 TIME_WAIT\uff1f<\/h3>\n\n\n\n

                    \u4fdd\u8bc1\u6700\u540eACK\u53ef\u9760\u9001\u8fbe\u3001\u6e05\u7a7a\u94fe\u8def\u6b8b\u7559\u65e7\u62a5\u6587\uff0c\u907f\u514d\u65b0\u8fde\u63a5\u5f02\u5e38\u3002<\/p>\n\n\n\n

                    6.tcp\u4e3a\u4ec0\u4e48\u53ef\u9760\uff1f<\/p>\n\n\n\n

                    \u6709\u4ee5\u4e0b\u539f\u56e0\uff1a<\/p>\n\n\n\n

                      \n
                    • ack\u786e\u8ba4\u6570\u636e\u5b8c\u6574\u5ea6\uff1a\u5728\u63a5\u6536\u6570\u636e\u65f6\uff0c\u6bcf\u4e00\u4e2a\u5b57\u8282\u90fd\u6709\u81ea\u5df1\u7684\u5e8f\u5217\u53f7\uff0c\u53d1\u9001\u65b9\u53d1\u9001\u540e\u5982\u679c\u63a5\u6536\u4e0d\u5230ack\u5c31\u4f1a\u4e00\u76f4\u91cd\u590d\u53d1\u9001\uff0c\u4fdd\u8bc1\u6570\u636e\u7684\u987a\u5e8f\u548c\u5b8c\u6574\u6027<\/li>\n\n\n\n
                    • \u6821\u9a8c\u548c\uff1a\u63a5\u6536\u65b9\u6536\u5230\u540e\u4f1a\u8ba1\u7b97\u6821\u9a8c\u548c\uff0c\u6821\u9a8c\u5931\u8d25\u76f4\u63a5\u4e22\u5f03\uff0c\u7b49\u5f85\u91cd\u4f20\uff0c<\/li>\n\n\n\n
                    • mss\u673a\u5236\uff1a\u5728\u8bf7\u6c42\u5efa\u7acb\u7684\u65f6\u5019\u53ef\u4ee5\u6dfb\u52a0\u7684\u6bcf\u6b21\u4e0a\u4f20\u6700\u5927\u7684\u6570\u636e\u91cf\uff0c\u53ea\u51fa\u73b0\u5728SYN\u4e2d\uff0c\u8d8a\u5927\u7f51\u7edc\u7684\u5229\u7528\u7387\u8d8a\u9ad8<\/li>\n\n\n\n
                    • \u91cd\u4f20\u673a\u5236\uff1a\u5f53\u53d1\u9001\u65b9\u53d1\u9001\u4e86\u76f8\u5173\u6570\u636e\u4f46\u6ca1\u6709\u63a5\u6536\u5230\u5bf9\u5e94\u7684ack\u65f6\uff0c\u7b49\u5f85\u4e00\u5b9a\u65f6\u95f4\u4f1a\u91cd\u4f20\u6570\u636e\uff1b\u4e14\u82e5\u540c\u65f6\u6536\u5230\u4e09\u4e2a\u76f8\u540c\u7684ack\u65f6\u8bf4\u660e\u4f20\u8f93\u5931\u8d25\uff0c\u4f1a\u65e0\u89c6RTO\u76f4\u63a5\u5feb\u901f\u91cd\u4f20\uff08\u901f\u5ea6\u66f4\u5feb\uff09<\/li>\n\n\n\n
                    • SACK\uff08\u9009\u62e9\u6027\u786e\u8ba4\uff09\uff1a\u5728\u9009\u9879\u5b57\u6bb5\u544a\u8bc9\u53d1\u9001\u65b9\u90a3\u4e9b\u6570\u636e\u4f4d\u7f6e\u4e22\u5931\uff0c\u53d1\u9001\u65b9\u53ea\u7528\u53d1\u9001\u7f3a\u5931\u7684\uff0c\u4e0d\u7528\u5168\u90e8\u91cd\u65b0\u53d1\u9001<\/li>\n\n\n\n
                    • D-SACK\uff08\u91cd\u590dsack\uff09\uff1a\u544a\u8bc9\u53d1\u9001\u65b9\u54ea\u4e9b\u6570\u636e\u91cd\u590d\u53d1\u9001\u4e86\uff0c\u7528\u4e8e\u5224\u65ad\u662f\u5426\u5931\u5e8f\u4e22\u5931\u7b49<\/li>\n\n\n\n
                    • \u4e09\u6b21\u63e1\u624b\u5efa\u7acb\u53ef\u9760\u548c\u56db\u6b21\u6325\u624b\u786e\u4fdd\u8fde\u63a5\u65ad\u5f00\u6709\u5e8f<\/li>\n<\/ul>\n\n\n\n

                      \u516b\u3001\u5168\u6587\u603b\u7ed3<\/h2>\n\n\n\n

                      TCP \u7684\u6240\u6709\u8bbe\u8ba1\u903b\u8f91\uff0c\u5f52\u6839\u5230\u5e95\u4e09\u4ef6\u4e8b\uff1a<\/p>\n\n\n\n

                        \n
                      1. \u7528 SEQ\/ACK \u4fdd\u8bc1\u53ef\u9760\u6709\u5e8f<\/strong><\/li>\n\n\n\n
                      2. \u7528\u7a97\u53e3\u4fdd\u8bc1\u7aef\u4fa7\u6536\u53d1\u5339\u914d<\/strong><\/li>\n\n\n\n
                      3. \u7528\u62e5\u585e\u7b97\u6cd5\u4fdd\u8bc1\u7f51\u7edc\u94fe\u8def\u7a33\u5b9a<\/strong><\/li>\n<\/ol>\n\n\n\n

                        \u4e09\u6b21\u63e1\u624b\u5efa\u901a\u9053\u3001\u56db\u6b21\u6325\u624b\u62c6\u901a\u9053\u3001\u6807\u5fd7\u4f4d\u5904\u7406\u7279\u6b8a\u573a\u666f\u3001\u53cc\u7a97\u53e3\u63a7\u5236\u4f20\u8f93\u901f\u5ea6\uff0c\u8fd9\u5c31\u662f TCP \u5b8c\u6574\u7684\u6838\u5fc3\u4f53\u7cfb\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

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