{"id":96845,"date":"2020-04-26T17:40:08","date_gmt":"2020-04-26T09:40:08","guid":{"rendered":"http:\/\/4563.org\/?p=96845"},"modified":"2020-04-26T17:40:08","modified_gmt":"2020-04-26T09:40:08","slug":"%e4%b8%ba%e4%bd%95-tcp-%e4%b8%ad%e7%9a%84-time_wait-%e7%8a%b6%e6%80%81%e6%8c%81%e7%bb%ad-2msl-%e8%80%8c%e4%b8%8d%e6%98%af-msl-%e5%91%a2%ef%bc%9f","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=96845","title":{"rendered":"\u4e3a\u4f55 tcp \u4e2d\u7684 time_wait \u72b6\u6001\u6301\u7eed 2msl \u800c\u4e0d\u662f msl \u5462\uff1f"},"content":{"rendered":"
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\u4e3a\u4f55 tcp \u4e2d\u7684 time_wait \u72b6\u6001\u6301\u7eed 2msl \u800c\u4e0d\u662f msl \u5462\uff1f <\/h1>\n

<\/p>\n

\n
\u8cc7\u6df1\u5927\u4f6c : jdz <\/span> <\/i> 55<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
\u4e86\u89e3\u4e3a\u4f55\u9700\u8981 time_wait \u72b6\u6001\uff0c\u4f46\u662f\u4e0d\u6e05\u695a\u4e3a\u4f55\u662f 2msl <\/div>\n
\u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (9<\/span>) <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n
    \n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : hfutzj <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u4ec5\u4f9b\u53c2\u8003\uff0c\u6709\u9519\u8bef\u6b22\u8fce\u6307\u51fa
    \u8bb0\u5f97\u6709\u4e24\u4e2a\u539f\u56e0\uff0c\u4e00\u4e2a\u662f\u4fdd\u8bc1\u6240\u6709\u6d88\u606f\u751f\u5b58\u671f\u8fc7\u4e86\uff0c\u4e8c\u662f\u4fdd\u8bc1\u6700\u540e\u53d1\u51fa\u7684\u65ad\u5f00\u8fde\u63a5\u7684\u6d88\u606f\u5bf9\u9762\u80fd\u591f\u6536\u5230 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : palmers <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    unix \u7f51\u7edc\u7f16\u7a0b\u5377 1 \u7b2c 38 \u9875\u6458\u5f55\u6709
    1. \u53ef\u9760\u5730\u5b9e\u73b0 TCP \u5168\u53cc\u5de5\u8fde\u63a5\u7684\u7ec8\u6b62\u3002\uff08\u786e\u4fdd\u6700\u540e\u7684 ACK \u80fd\u8ba9\u88ab\u5173\u95ed\u65b9\u63a5\u6536\uff09\uff1b
    2. \u5141\u8bb8\u8001\u7684\u91cd\u590d\u5206\u8282\u5728\u7f51\u7edc\u4e2d\u6d88\u901d\u3002\uff08 TCP \u4e2d\u662f\u53ef\u9760\u7684\u670d\u52a1\uff0c\u5f53\u6570\u636e\u5305\u4e22\u5931\u4f1a\u91cd\u4f20\uff0c\u5f53\u6709\u6570\u636e\u5305\u8ff7\u8def\u7684\u60c5\u51b5\u4e0b\uff0c\u5982\u679c\u4e0d\u7b49\u5f85 2MSL \u65f6\uff0c\u5f53\u5ba2\u6237\u7aef\u4ee5\u540c\u6837\u5730\u65b9\u5f0f\u91cd\u65b0\u548c\u670d\u52a1\u5efa\u7acb\u8fde\u63a5\u540e\uff0c\u4e0a\u4e00\u6b21\u8ff7\u8def\u7684\u6570\u636e\u5305\u8fd9\u65f6\u53ef\u80fd\u4f1a\u5230\u8fbe\u670d\u52a1\uff0c\u8fd9\u65f6\u4f1a\u9020\u6210\u65e7\u5305\u88ab\u91cd\u65b0\u8bfb\u53d6\uff09\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : jdz <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @palmers \u8fd9\u4e2a\u6211\u5012\u4e86\u89e3\uff0c\u4f46\u4e0d\u4e86\u89e3\u4e3a\u4f55\u8981\u7b49\u8fd9\u4e48\u4e45\uff0c\u800c\u4e0d\u662f\u53ea\u7b49\u5f85 msl <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : ChristopherWu <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u603b\u7ed3\uff1a\u786e\u4fdd\u72b6\u6001\u6b63\u786e\uff0c\u4e5f\u5c31\u662f\u4e0a\u9762\u7684\u540c\u5b66\u8bf4\u7684 \u201c\u4fdd\u8bc1\u6700\u540e\u53d1\u51fa\u7684\u65ad\u5f00\u8fde\u63a5\u7684\u6d88\u606f\u5bf9\u9762\u80fd\u591f\u6536\u5230\u201d<\/p>\n

    “`
    TCP A TCP B<\/p>\n

    1. ESTABLISHED ESTABLISHED<\/p>\n

    2. (Close)
    FIN-WAIT-1 –> <SEQ=100><ACK=300><CTL=FIN,ACK> –> CLOSE-WAIT<\/p>\n

    3. FIN-WAIT-2 <– <SEQ=300><ACK=101><CTL=ACK> <– CLOSE-WAIT<\/p>\n

    4. (Close)
    TIME-WAIT <– <SEQ=300><ACK=101><CTL=FIN,ACK> <– LAST-ACK<\/p>\n

    5. TIME-WAIT –> <SEQ=101><ACK=301><CTL=ACK> –> CLOSED<\/p>\n

    6. (2 MSL)
    CLOSED<\/p>\n

    Normal Close Sequence
    “`<\/p>\n

    \u5728\u6700\u540e\u7684 4\u30015 \u9636\u6bb5\uff0c\u5047\u5982 5 \u8fd4\u56de\u7ed9`TCP B`\u7684\u65f6\u5019\uff0c`1 msl` \u8fc7\u53bb\u4e86\uff0c\u62a5\u6587\u8fc7\u671f\u4e86\uff1b`TCP B` \u6ca1\u6709\u6536\u5230\uff0c\u518d\u53d1\u4e00\u904d\uff0c\u5982\u679c\u8bbe\u7f6e `time_wait \u72b6\u6001` \u662f `1msl`\uff0c\u90a3\u4e48 `TCP A` \u5904\u4e8e`closed`\u72b6\u6001\uff0c\u62d2\u6536`TCP B`\u7684`FIN \u5305`\uff0cB \u65e0\u6cd5\u5173\u95ed\u3002<\/p>\n

    \u6240\u4ee5\u8981\u8bbe\u7f6e\u5927\u4e8e 1MSL\u3002<\/p>\n

    \u800c TCP B \u91cd\u4f20\u8fc7\u6765\u7684\u5305\uff0c\u4f60\u4e5f\u8981\u5047\u8bbe\u4ed6\u53ef\u80fd\u9700\u8981`1 msl`\u5427\uff0c\u90a3\u4e48 time_wait \u5c31\u8981`2 msl`\u7684\u65f6\u95f4\u6765\u4fdd\u8bc1\u6b64\u6781\u7aef\u60c5\u51b5\u4e0b\uff0cB \u80fd\u91cd\u4f20\u6210\u529f\u3002 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : crab <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u4e00\u53bb\u6700\u5927\u503c msl \u4e00\u56de\u6700\u5927\u503c msl <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : wisej <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @jdz \u56e0\u4e3a\u5982\u679c\u7b2c\u56db\u6b21\u7684 ack \u53ef\u80fd\u4e22\u5931\uff0c\u800c\u52a0\u4e0a\u662f\u4e00\u53bb\u4e00\u56de\uff0c\u6240\u4ee5\u662f 2msl <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : goofool <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u4e00\u4e2a\u6765\u56de\u65f6\u95f4 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : palmers <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @jdz \u4f60\u7684\u7591\u95ee \u5728\u7b2c\u4e8c\u6761\u6709\u89e3\u91ca\u554a\uff0c \u6211\u731c\u6d4b\u4f60\u7591\u60d1\u7684\u662f 2MSL \u7684\u5b9a\u4e49\u5427\uff1f <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : RedisMasterNode <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    TCPB \u5411 TCPA \u53d1\u9001 Last ACK\uff0c\u62b5\u8fbe\u9700\u8981 1 \u4e2a MSL\uff0c\u62b5\u8fbe\u540e TCPA \u4ece FIN_WAIT_2 \u53d8\u6210 TIME_WAIT \u72b6\u6001\uff0c\u5e76\u4e14\u8fd4\u56de ACK \u5bf9 TCPB \u8fdb\u884c\u54cd\u5e94\uff0c\u5982\u679c\u4e00\u5207\u6b63\u5e38\uff0c\u90a3\u4e48\u518d\u8fc7 1 \u4e2a MSL \u4e4b\u540e\u5c31\u4f1a\u62b5\u8fbe B<\/p>\n

    \u5047\u5982 TCP A \u7684\u8fd9\u4e2a ACK \u6ca1\u6709\u62b5\u8fbe B\uff0c\u90a3\u4e48\u5bf9\u4e8e B \u6765\u8bf4\uff0cB \u53d1\u9001\u4e86\u4e00\u4e2a Last ACK \u51fa\u53bb\uff0c\u5904\u4e8e CLOSE_WAIT \u72b6\u6001\uff0c\u7b49\u5f85 A \u7684 ACK \u56de\u6765\uff0c\u5982\u679c B \u5728\u53d1\u4e86 ACK \u540e\u8fc7\u4e86 2 \u4e2a MSL \u540e\u6ca1\u6709\u6536\u5230 A \u7684 ACK\uff0c\u90a3\u4e48\u5c31\u4f1a\u91cd\u65b0\u53d1\u8fd9\u4e2a FIN \u62a5\u6587<\/p>\n

    A \u7b49\u5f85\u4e24\u4e2a ACK \u7684\u76ee\u7684\u662f\u5728\u4e8e\u9632\u6b62 ACK \u5728\u4f20\u8f93\u8fc7\u7a0b\u4e2d\u4e22\u5931\uff0c\u90a3\u4e48\u5bf9\u4e8e B \u6765\u8bf4\u4f1a\u5728 A \u7b49\u5f85 1 \u4e2a MSL \uff08\u8fd9\u65f6 B \u5df2\u7ecf\u7b49\u5f85\u4e86\u4e24\u4e2a MSL \uff09\u540e\u91cd\u53d1\u62a5\u6587\uff0c\u8fd9\u4e2a\u62a5\u6587\u8fc7 1MSL \u4e4b\u540e\u5185\u4f1a\u62b5\u8fbe A\uff0c\u6240\u4ee5 A \u53ef\u4ee5\u5728 2 \u4e2a MSL \u5185\u786e\u8ba4\u5230 B \u662f\u5426\u6ca1\u6709\u63a5\u5230\u81ea\u5df1\u7684 ACK <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n","protected":false},"excerpt":{"rendered":"

    \u4e3a\u4f55 tcp \u4e2d\u7684 time_wa…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/96845"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=96845"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/96845\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=96845"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=96845"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=96845"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}