{"id":570,"date":"2021-09-12T20:08:10","date_gmt":"2021-09-12T12:08:10","guid":{"rendered":"http:\/\/dba.qishuo.xin\/?p=570"},"modified":"2021-09-12T20:08:10","modified_gmt":"2021-09-12T12:08:10","slug":"%e4%bd%bf%e7%94%a8netstat%e6%9f%a5%e7%9c%8btcp%e8%bf%9e%e6%8e%a5%e3%80%81udp%e8%bf%9e%e6%8e%a5","status":"publish","type":"post","link":"http:\/\/dba.qishuo.xin\/?p=570","title":{"rendered":"\u4f7f\u7528netstat\u67e5\u770btcp\u8fde\u63a5\u3001udp\u8fde\u63a5"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_76 ez-toc-wrap-right counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<label for=\"ez-toc-cssicon-toggle-item-6a020c8bc7208\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-6a020c8bc7208\" checked aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"http:\/\/dba.qishuo.xin\/?p=570\/#1_%E6%9F%A5%E7%9C%8Btcp%E3%80%81udp%E8%BF%9E%E6%8E%A5\" >1. \u67e5\u770btcp\u3001udp\u8fde\u63a5<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"http:\/\/dba.qishuo.xin\/?p=570\/#2_TCP%E8%BF%9E%E6%8E%A5%E7%8A%B6%E6%80%81%E8%AF%B4%E6%98%8E\" >2. TCP\u8fde\u63a5\u72b6\u6001\u8bf4\u660e<\/a><\/li><\/ul><\/nav><\/div>\n<h4><span class=\"ez-toc-section\" id=\"1_%E6%9F%A5%E7%9C%8Btcp%E3%80%81udp%E8%BF%9E%E6%8E%A5\"><\/span>1. \u67e5\u770btcp\u3001udp\u8fde\u63a5<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<pre><code class=\"line-numbers\">~]# netstat -nt    ---&gt;&gt;&gt;\u67e5\u770btcp\u8fde\u63a5\uff0c\u6ce8\u610f\u770b\u7b2c\u4e8c\u5217\u548c\u7b2c\u4e09\u5217\nActive Internet connections (w\/o servers)\nProto Recv-Q Send-Q Local Address           Foreign Address         State\ntcp        1      0 192.168.11.82:8080      192.168.11.81:56208     CLOSE_WAIT\ntcp        0      0 192.168.11.82:22        172.16.69.49:6160       ESTABLISHED\ntcp        1      0 192.168.11.82:8080      192.168.11.81:56203     CLOSE_WAIT\ntcp        1      0 192.168.11.82:8080      192.168.11.81:56201     CLOSE_WAIT\ntcp        1      0 192.168.11.82:8080      192.168.11.81:56204     CLOSE_WAIT\ntcp        1      0 192.168.11.82:8080      192.168.11.81:56205     CLOSE_WAIT\ntcp        1      0 192.168.11.82:8080      192.168.11.81:56202     CLOSE_WAIT\ntcp        0     36 192.168.11.82:22        172.16.69.49:6291       ESTABLISHED\n\n~]# netstat -nua  ---&gt;&gt;&gt;\u67e5\u770budp\u8fde\u63a5\uff0c\u6ce8\u610f\u770b\u7b2c\u4e8c\u5217\u548c\u7b2c\u4e09\u5217\nActive Internet connections (servers and established)\nProto Recv-Q Send-Q Local Address           Foreign Address         State\nudp        0      0 0.0.0.0:5353            0.0.0.0:*\nudp        0      0 0.0.0.0:48638           0.0.0.0:*\nudp        0      0 192.168.122.1:53        0.0.0.0:*\nudp        0      0 0.0.0.0:67              0.0.0.0:*\nudp        0      0 0.0.0.0:111             0.0.0.0:*\nudp        0      0 127.0.0.1:323           0.0.0.0:*\nudp        0      0 0.0.0.0:777             0.0.0.0:*\nudp6       0      0 :::111                  :::*\nudp6       0      0 ::1:323                 :::*\nudp6       0      0 :::777                  :::*\n\n<\/code><\/pre>\n<p>\u5982\u4e0b\u53d6\u81eaman netstat\u7684\u7ed3\u679c\uff1a<br \/>\n   Recv-Q<br \/>\n       Established: The count of bytes not copied by the user program connected to this socket.<br \/>\n       Listening: Since Kernel 2.6.18 this column contains the current syn backlog.<br \/>\n   Send-Q<br \/>\n       Established: The count of bytes not acknowledged by the remote host.<br \/>\n       Listening: Since Kernel 2.6.18 this column contains the maximum size of the syn backlog.<\/p>\n<p><strong>Recv-Q Send-Q\u5206\u522b\u8868\u793a\u7f51\u7edc\u63a5\u6536\u961f\u5217\u3001\u7f51\u7edc\u53d1\u9001\u961f\u5217\u3002Q\u662fQueue\u7684\u7f29\u5199\u3002<\/strong><br \/>\nrecv-Q \u8868\u793a\u7f51\u7edc\u63a5\u6536\u961f\u5217<br \/>\n\u8868\u793a\u6536\u5230\u7684\u6570\u636e\u5df2\u7ecf\u5728\u672c\u5730\u63a5\u6536\u7f13\u51b2\uff0c\u4f46\u662f\u8fd8\u6709\u591a\u5c11\u6ca1\u6709\u88ab\u8fdb\u7a0b\u53d6\u8d70\uff0crecv()<br \/>\n\u5982\u679c\u63a5\u6536\u961f\u5217Recv-Q\u4e00\u76f4\u5904\u4e8e\u963b\u585e\u72b6\u6001\uff0c\u53ef\u80fd\u662f\u906d\u53d7\u4e86\u62d2\u7edd\u670d\u52a1 denial-of-service \u653b\u51fb\u3002<\/p>\n<p>send-Q \u8868\u793a\u7f51\u8def\u53d1\u9001\u961f\u5217<br \/>\n\u5bf9\u65b9\u6ca1\u6709\u6536\u5230\u7684\u6570\u636e\u6216\u8005\u8bf4\u6ca1\u6709Ack\u7684,\u8fd8\u662f\u672c\u5730\u7f13\u51b2\u533a.<br \/>\n\u5982\u679c\u53d1\u9001\u961f\u5217Send-Q\u4e0d\u80fd\u5f88\u5feb\u7684\u6e05\u96f6\uff0c\u53ef\u80fd\u662f\u6709\u5e94\u7528\u5411\u5916\u53d1\u9001\u6570\u636e\u5305\u8fc7\u5feb\uff0c\u6216\u8005\u662f\u5bf9\u65b9\u63a5\u6536\u6570\u636e\u5305\u4e0d\u591f\u5feb\u3002<\/p>\n<h4><span class=\"ez-toc-section\" id=\"2_TCP%E8%BF%9E%E6%8E%A5%E7%8A%B6%E6%80%81%E8%AF%B4%E6%98%8E\"><\/span>2. TCP\u8fde\u63a5\u72b6\u6001\u8bf4\u660e<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<pre><code class=\"language-shell line-numbers\">netstat -n | awk '\/^tcp\/ {++S[$NF]} END {for(a in S) print a, S[a]}'\n\u6216\u8005\u4f7f\u7528\nnetstat -an|awk '\/tcp\/ {print $6}'| sort | uniq -c\n<\/code><\/pre>\n<p>TIME_WAIT    8947<br \/>\nFIN_WAIT1    15<br \/>\nFIN_WAIT2    1<br \/>\nESTABLISHED  55<br \/>\nSYN_RECV     21<br \/>\nCLOSING      2<br \/>\nLAST_ACK     4<\/p>\n<p>TCP\u8fde\u63a5\u72b6\u6001\u8be6\u89e3\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th align=\"left\">\u72b6\u6001\uff08state)<\/th>\n<th align=\"left\">\u8bf4\u660e----------------------------------------------------------------------------<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td align=\"left\">LISTEN<\/td>\n<td align=\"left\">\u4fa6\u542c\u6765\u81ea\u8fdc\u65b9\u7684TCP\u7aef\u53e3\u7684\u8fde\u63a5\u8bf7\u6c42<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">SYN-SENT<\/td>\n<td align=\"left\">\u518d\u53d1\u9001\u8fde\u63a5\u8bf7\u6c42\u540e\u7b49\u5f85\u5339\u914d\u7684\u8fde\u63a5\u8bf7\u6c42<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">SYN-RECEIVED<\/td>\n<td align=\"left\">\u518d\u6536\u5230\u548c\u53d1\u9001\u4e00\u4e2a\u8fde\u63a5\u8bf7\u6c42\u540e\u7b49\u5f85\u5bf9\u65b9\u5bf9\u8fde\u63a5\u8bf7\u6c42\u7684\u786e\u8ba4<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">ESTABLISHED<\/td>\n<td align=\"left\">\u4ee3\u8868\u4e00\u4e2a\u6253\u5f00\u7684\u8fde\u63a5<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">FIN-WAIT-1<\/td>\n<td align=\"left\">\u7b49\u5f85\u8fdc\u7a0bTCP\u8fde\u63a5\u4e2d\u65ad\u8bf7\u6c42\uff0c\u6216\u5148\u524d\u7684\u8fde\u63a5\u4e2d\u65ad\u8bf7\u6c42\u7684\u786e\u8ba4<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">FIN-WAIT-2<\/td>\n<td align=\"left\">\u4ece\u8fdc\u7a0bTCP\u7b49\u5f85\u8fde\u63a5\u4e2d\u65ad\u8bf7\u6c42<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">CLOSE-WAIT<\/td>\n<td align=\"left\">\u7b49\u5f85\u4ece\u672c\u5730\u7528\u6237\u53d1\u6765\u7684\u8fde\u63a5\u4e2d\u65ad\u8bf7\u6c42<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">CLOSING<\/td>\n<td align=\"left\">\u7b49\u5f85\u8fdc\u7a0bTCP\u5bf9\u8fde\u63a5\u4e2d\u65ad\u7684\u786e\u8ba4<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">LAST-ACK<\/td>\n<td align=\"left\">\u7b49\u5f85\u539f\u6765\u7684\u53d1\u5411\u8fdc\u7a0bTCP\u7684\u8fde\u63a5\u4e2d\u65ad\u8bf7\u6c42\u7684\u786e\u8ba4<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">TIME-WAIT<\/td>\n<td align=\"left\">\u7b49\u5f85\u8db3\u591f\u7684\u65f6\u95f4\u4ee5\u786e\u4fdd\u8fdc\u7a0bTCP\u63a5\u6536\u5230\u8fde\u63a5\u4e2d\u65ad\u8bf7\u6c42\u7684\u786e\u8ba4<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">CLOSED<\/td>\n<td align=\"left\">\u6ca1\u6709\u4efb\u4f55\u8fde\u63a5\u72b6\u6001<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"<p>1. \u67e5\u770btcp\u3001udp\u8fde\u63a5 ~]# netsta&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[48,80,81],"class_list":["post-570","post","type-post","status-publish","format-standard","hentry","category-linux","tag-linux","tag-tcp","tag-udp"],"_links":{"self":[{"href":"http:\/\/dba.qishuo.xin\/index.php?rest_route=\/wp\/v2\/posts\/570","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/dba.qishuo.xin\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/dba.qishuo.xin\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/dba.qishuo.xin\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/dba.qishuo.xin\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=570"}],"version-history":[{"count":1,"href":"http:\/\/dba.qishuo.xin\/index.php?rest_route=\/wp\/v2\/posts\/570\/revisions"}],"predecessor-version":[{"id":571,"href":"http:\/\/dba.qishuo.xin\/index.php?rest_route=\/wp\/v2\/posts\/570\/revisions\/571"}],"wp:attachment":[{"href":"http:\/\/dba.qishuo.xin\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=570"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/dba.qishuo.xin\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=570"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/dba.qishuo.xin\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=570"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}