{"id":358,"date":"2016-01-21T12:32:02","date_gmt":"2016-01-21T04:32:02","guid":{"rendered":"http:\/\/blog.sway.com.cn\/?p=358"},"modified":"2016-01-21T12:32:37","modified_gmt":"2016-01-21T04:32:37","slug":"%e5%88%a9%e7%94%a8iptables%e6%9d%a5%e9%85%8d%e7%bd%aelinux%e7%a6%81%e6%ad%a2%e6%89%80%e6%9c%89%e7%ab%af%e5%8f%a3%e7%99%bb%e9%99%86%e5%92%8c%e5%bc%80%e6%94%be%e6%8c%87%e5%ae%9a%e7%ab%af%e5%8f%a3","status":"publish","type":"post","link":"http:\/\/blog.sway.com.cn\/?p=358","title":{"rendered":"\u5229\u7528iptables\u6765\u914d\u7f6elinux\u7981\u6b62\u6240\u6709\u7aef\u53e3\u767b\u9646\u548c\u5f00\u653e\u6307\u5b9a\u7aef\u53e3"},"content":{"rendered":"<p>1\u3001\u5173\u95ed\u6240\u6709\u7684 INPUT FORWARD OUTPUT \u53ea\u5bf9\u67d0\u4e9b\u7aef\u53e3\u5f00\u653e\u3002<br \/>\n\u4e0b\u9762\u662f\u547d\u4ee4\u5b9e\u73b0\uff1a<\/p>\n<p><strong>iptables -P INPUT DROP<br \/>\niptables -P FORWARD DROP<br \/>\niptables -P OUTPUT DROP<\/strong><\/p>\n<p>\u518d\u7528\u547d\u4ee4 iptables -L -n \u67e5\u770b \u662f\u5426\u8bbe\u7f6e\u597d\uff0c \u597d\u770b\u5230\u5168\u90e8 DROP \u4e86<br \/>\n\u8fd9\u6837\u7684\u8bbe\u7f6e\u597d\u4e86\uff0c\u6211\u4eec\u53ea\u662f\u4e34\u65f6\u7684\uff0c \u91cd\u542f\u670d\u52a1\u5668\u8fd8\u662f\u4f1a\u6062\u590d\u539f\u6765\u6ca1\u6709\u8bbe\u7f6e\u7684\u72b6\u6001<br \/>\n\u8fd8\u8981\u4f7f\u7528 <strong>service iptables save<\/strong> \u8fdb\u884c\u4fdd\u5b58<br \/>\n\u770b\u5230\u4fe1\u606f firewall rules \u9632\u706b\u5899\u7684\u89c4\u5219 \u5176\u5b9e\u5c31\u662f\u4fdd\u5b58\u5728 \/etc\/sysconfig\/iptables<br \/>\n\u53ef\u4ee5\u6253\u5f00\u6587\u4ef6\u67e5\u770b <strong>vi \/etc\/sysconfig\/iptables<\/strong><br \/>\n2\u3001<br \/>\n\u4e0b\u9762\u6211\u53ea\u6253\u5f0022\u7aef\u53e3\uff0c\u770b\u6211\u662f\u5982\u4f55\u64cd\u4f5c\u7684\uff0c\u5c31\u662f\u4e0b\u97622\u4e2a\u8bed\u53e5<\/p>\n<p><strong>\u00a0\u00a0\u00a0 iptables -A INPUT -p tcp &#8211;dport 22 -j ACCEPT<br \/>\niptables -A OUTPUT -p tcp &#8211;sport 22 -j ACCEPT<\/strong><\/p>\n<p>\u518d\u67e5\u770b\u4e0b iptables -L -n \u662f\u5426\u6dfb\u52a0\u4e0a\u53bb, \u770b\u5230\u6dfb\u52a0\u4e86<\/p>\n<p>Chain INPUT (policy DROP)<br \/>\ntarget\u00a0\u00a0\u00a0\u00a0 prot opt source\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destination<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp dpt:22<\/p>\n<p>Chain FORWARD (policy DROP)<br \/>\ntarget\u00a0\u00a0\u00a0\u00a0 prot opt source\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destination<\/p>\n<p>Chain OUTPUT (policy DROP)<br \/>\ntarget\u00a0\u00a0\u00a0\u00a0 prot opt source\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destination<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp spt:22<\/p>\n<p>\u73b0\u5728Linux\u670d\u52a1\u5668\u53ea\u6253\u5f00\u4e8622\u7aef\u53e3\uff0c\u7528putty.exe\u6d4b\u8bd5\u4e00\u4e0b\u662f\u5426\u53ef\u4ee5\u94fe\u63a5\u4e0a\u53bb\u3002<br \/>\n\u53ef\u4ee5\u94fe\u63a5\u4e0a\u53bb\u4e86\uff0c\u8bf4\u660e\u6ca1\u6709\u95ee\u9898\u3002<\/p>\n<p>\u6700\u540e\u522b\u5fd8\u8bb0\u4e86\u4fdd\u5b58 \u5bf9\u9632\u706b\u5899\u7684\u8bbe\u7f6e<br \/>\n\u901a\u8fc7\u547d\u4ee4\uff1a<strong>service iptables save<\/strong> \u8fdb\u884c\u4fdd\u5b58<\/p>\n<p>iptables -A INPUT -p tcp &#8211;dport 22 -j ACCEPT<br \/>\niptables -A OUTPUT -p tcp &#8211;sport 22 -j ACCEPT<br \/>\n\u9488\u5bf9\u8fd92\u6761\u547d\u4ee4\u8fdb\u884c\u4e00\u4e9b\u8bb2\u89e3\u5427<br \/>\n<strong>-A <\/strong>\u53c2\u6570\u5c31\u770b\u6210\u662f\u6dfb\u52a0\u4e00\u6761 INPUT \u7684\u89c4\u5219<br \/>\n<strong>-p<\/strong> \u6307\u5b9a\u662f\u4ec0\u4e48\u534f\u8bae \u6211\u4eec\u5e38\u7528\u7684tcp \u534f\u8bae\uff0c\u5f53\u7136\u4e5f\u6709udp \u4f8b\u598253\u7aef\u53e3\u7684DNS<br \/>\n\u5230\u65f6\u6211\u4eec\u8981\u914d\u7f6eDNS\u7528\u523053\u7aef\u53e3 \u5927\u5bb6\u5c31\u4f1a\u53d1\u73b0\u4f7f\u7528udp\u534f\u8bae\u7684<\/p>\n<p>\u800c<strong> &#8211;dport <\/strong>\u5c31\u662f\u76ee\u6807\u7aef\u53e3 \u5f53\u6570\u636e\u4ece\u5916\u90e8\u8fdb\u5165\u670d\u52a1\u5668\u4e3a\u76ee\u6807\u7aef\u53e3<br \/>\n\u53cd\u4e4b \u6570\u636e\u4ece\u670d\u52a1\u5668\u51fa\u53bb \u5219\u4e3a\u6570\u636e\u6e90\u7aef\u53e3 \u4f7f\u7528<strong> &#8211;sport<\/strong><\/p>\n<p>-j \u5c31\u662f\u6307\u5b9a\u662f ACCEPT \u63a5\u6536 \u6216\u8005 DROP \u4e0d\u63a5\u6536<br \/>\n3\u3001\u7981\u6b62\u67d0\u4e2aIP\u8bbf\u95ee<br \/>\n1\u53f0Linux\u670d\u52a1\u5668,2\u53f0windows xp \u64cd\u4f5c\u7cfb\u7edf\u8fdb\u884c\u8bbf\u95ee<br \/>\nLinux\u670d\u52a1\u5668ip 192.168.1.99<br \/>\nxp1 ip: 192.168.1.2<br \/>\nxp2 ip: 192.168.1.8<\/p>\n<p>\u4e0b\u9762\u770b\u770b\u62112\u53f0xp \u90fd\u53ef\u4ee5\u8bbf\u95ee\u7684<\/p>\n<p>192.168.1.2\u00a0 \u8fd9\u662f xp1 \u53ef\u4ee5\u8bbf\u95ee\u7684\uff0c<br \/>\n192.168.1.8 xp2 \u4e5f\u662f\u53ef\u4ee5\u6b63\u5e38\u8bbf\u95ee\u7684\u3002<\/p>\n<p>\u90a3\u4e48\u73b0\u5728\u6211\u8981\u7981\u6b62 192.168.1.2 xp1 \u8bbf\u95ee\uff0c xp2 \u6b63\u5e38\u8bbf\u95ee\uff0c<br \/>\n\u4e0b\u9762\u770b\u770b\u6f14\u793a<\/p>\n<p>\u901a\u8fc7\u547d\u4ee4 <strong>iptables -A INPUT -p tcp -s 192.168.1.2 -j DROP<\/strong><br \/>\n\u8fd9\u91cc\u610f\u601d\u5c31\u662f -A \u5c31\u662f\u6dfb\u52a0\u65b0\u7684\u89c4\u5219\uff0c \u600e\u6837\u7684\u89c4\u5219\u5462\uff1f \u7531\u4e8e\u6211\u4eec\u8bbf\u95ee\u7f51\u7ad9\u4f7f\u7528tcp\u7684\uff0c<br \/>\n\u6211\u4eec\u5c31\u7528 -p tcp , \u5982\u679c\u662f udp \u5c31\u5199udp\uff0c\u8fd9\u91cc\u5c31\u7528tcp\u4e86\uff0c -s\u5c31\u662f \u6765\u6e90\u7684\u610f\u601d\uff0c<br \/>\nip\u6765\u6e90\u4e8e 192.168.1.2 \uff0c-j \u600e\u4e48\u505a \u6211\u4eec\u62d2\u7edd\u5b83 \u8fd9\u91cc\u5e94\u8be5\u662f DROP<\/p>\n<p>\u597d\uff0c\u770b\u770b\u6548\u679c\u3002\u597d\u6dfb\u52a0\u6210\u529f\u3002\u4e0b\u9762\u8fdb\u884c\u9a8c\u8bc1 \u4e00\u4e0b\u662f\u5426\u751f\u6548<\/p>\n<p>\u4e00\u76f4\u51fa\u73b0\u7b49\u5f85\u72b6\u6001 \u6700\u540e \u8be5\u9875\u65e0\u6cd5\u663e\u793a \uff0c\u8fd9\u662f 192.168.1.2 xp1 \u7684\u8bbf\u95ee\u88ab\u62d2\u7edd\u4e86\u3002<\/p>\n<p>\u518d\u770b\u770b\u53e6\u5916\u4e00\u53f0 xp \u662f\u5426\u53ef\u4ee5\u8bbf\u95ee\uff0c \u662f\u53ef\u4ee5\u6b63\u5e38\u8bbf\u95ee\u7684 192.168.1.8 \u662f\u53ef\u4ee5\u6b63\u5e38\u8bbf\u95ee\u7684<br \/>\n4\u3001\u5982\u4f55\u5220\u9664\u89c4\u5219<br \/>\n\u9996\u5148\u6211\u4eec\u8981\u77e5\u9053 \u8fd9\u6761\u89c4\u5219\u7684\u7f16\u53f7\uff0c\u6bcf\u6761\u89c4\u5219\u90fd\u6709\u4e00\u4e2a\u7f16\u53f7<\/p>\n<p>\u901a\u8fc7<strong> iptables -L -n &#8211;line-number <\/strong>\u53ef\u4ee5\u663e\u793a\u89c4\u5219\u548c\u76f8\u5bf9\u5e94\u7684\u7f16\u53f7<br \/>\nnum\u00a0 target\u00a0\u00a0\u00a0\u00a0 prot opt source\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destination<br \/>\n1\u00a0\u00a0\u00a0 DROP\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp dpt:3306<br \/>\n2\u00a0\u00a0\u00a0 DROP\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp dpt:21<br \/>\n3\u00a0\u00a0\u00a0 DROP\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp dpt:80<br \/>\n\u591a\u4e86 num \u8fd9\u4e00\u5217\uff0c \u8fd9\u6837\u6211\u4eec\u5c31\u53ef\u4ee5 \u770b\u5230\u521a\u624d\u7684\u89c4\u5219\u5bf9\u5e94\u7684\u662f \u7f16\u53f72<\/p>\n<p>\u90a3\u4e48\u6211\u4eec\u5c31\u53ef\u4ee5\u8fdb\u884c\u5220\u9664\u4e86<br \/>\n<strong> iptables -D INPUT 2<\/strong><br \/>\n\u5220\u9664INPUT\u94fe\u7f16\u53f7\u4e3a2\u7684\u89c4\u5219\u3002<\/p>\n<p>\u518d iptables -L -n \u67e5\u770b\u4e00\u4e0b \u5df2\u7ecf\u88ab\u6e05\u9664\u4e86\u3002<br \/>\n5\u3001\u8fc7\u6ee4\u65e0\u6548\u7684\u6570\u636e\u5305<br \/>\n\u5047\u8bbe\u6709\u4eba\u8fdb\u5165\u4e86\u670d\u52a1\u5668\uff0c\u6216\u8005\u6709\u75c5\u6bd2\u6728\u9a6c\u7a0b\u5e8f\uff0c\u5b83\u53ef\u4ee5\u901a\u8fc722\uff0c80\u7aef\u53e3\u50cf\u670d\u52a1\u5668\u5916\u4f20\u9001\u6570\u636e\u3002<br \/>\n\u5b83\u7684\u8fd9\u79cd\u65b9\u5f0f\u5c31\u548c\u6211\u4eec\u6b63\u5e38\u8bbf\u95ee22\uff0c80\u7aef\u53e3\u533a\u522b\u3002\u5b83\u53d1\u5411\u5916\u53d1\u7684\u6570\u636e\u4e0d\u662f\u6211\u4eec\u901a\u8fc7\u8bbf\u95ee\u7f51\u9875\u8bf7\u6c42<br \/>\n\u800c\u56de\u5e94\u7684\u6570\u636e\u5305\u3002<\/p>\n<p>\u4e0b\u9762\u6211\u4eec\u8981\u7981\u6b62\u8fd9\u4e9b\u6ca1\u6709\u901a\u8fc7\u8bf7\u6c42\u56de\u5e94\u7684\u6570\u636e\u5305\uff0c\u7edf\u7edf\u628a\u5b83\u4eec\u5835\u4f4f\u6389\u3002<\/p>\n<p>iptables \u63d0\u4f9b\u4e86\u4e00\u4e2a\u53c2\u6570 \u662f\u68c0\u67e5\u72b6\u6001\u7684\uff0c\u4e0b\u9762\u6211\u4eec\u6765\u914d\u7f6e\u4e0b 22 \u548c 80 \u7aef\u53e3\uff0c\u9632\u6b62\u65e0\u6548\u7684\u6570\u636e\u5305\u3002<\/p>\n<p><strong> iptables -A OUTPUT -p tcp \u2013sport 22 -m state \u2013state ESTABLISHED -j ACCEPT<\/strong><\/p>\n<p>\u53ef\u4ee5\u770b\u5230\u548c\u6211\u4eec\u4ee5\u524d\u4f7f\u7528\u7684\uff1a<br \/>\niptables -A OUTPUT -p tcp \u2013sport 22 -j ACCEPT<\/p>\n<p>\u591a\u4e86\u4e00\u4e2a\u72b6\u6001\u5224\u65ad\u3002<\/p>\n<p>\u540c\u683780\u7aef\u53e3\u4e5f\u4e00\u6837\uff0c \u73b0\u5728\u5220\u6389\u539f\u6765\u76842\u6761\u89c4\u5219\uff0c<br \/>\n<strong> iptables -L -n &#8211;line-number<\/strong>\u00a0\u00a0\u00a0 \u8fd9\u4e2a\u662f\u67e5\u770b\u89c4\u5219\u800c\u4e14\u5e26\u4e0a\u7f16\u53f7\u3002\u6211\u4eec\u770b\u5230\u7f16\u53f7\u5c31\u53ef\u4ee5<br \/>\n\u5220\u9664\u5bf9\u5e94\u7684\u89c4\u5219\u4e86\u3002<\/p>\n<p><strong>iptables -D OUTPUT 1\u00a0<\/strong>\u00a0\u00a0\u00a0 \u8fd9\u91cc\u76841\u8868\u793a\u7b2c\u4e00\u6761\u89c4\u5219\u3002<\/p>\n<p>\u5f53\u4f60\u5220\u9664\u4e86\u524d\u9762\u7684\u89c4\u5219\uff0c \u7f16\u53f7\u4e5f\u4f1a\u968f\u4e4b\u6539\u53d8\u3002\u770b\u5230\u4e86\u5427\u3002<\/p>\n<p>\u597d\uff0c\u6211\u4eec\u5220\u9664\u4e86\u524d\u97622\u4e2a\u89c4\u5219\uff0c22\u7aef\u53e3\u8fd8\u53ef\u4ee5\u6b63\u5e38\u4f7f\u7528\uff0c\u8bf4\u660e\u6ca1\u95ee\u9898\u4e86<\/p>\n<p>\u4e0b\u9762\u8fdb\u884c\u4fdd\u5b58\uff0c\u522b\u5fd8\u8bb0\u4e86\uff0c\u4e0d\u7136\u7684\u8bdd\u91cd\u542f\u5c31\u4f1a\u8fd8\u539f\u5230\u539f\u6765\u7684\u6837\u5b50\u3002<\/p>\n<p><strong>service iptables save<\/strong>\u00a0\u00a0\u00a0 \u8fdb\u884c\u4fdd\u5b58\u3002<\/p>\n<p>Saving firewall rules to \/etc\/sysconfig\/iptables:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 [\u00a0 OK\u00a0 ]<br \/>\n\u5176\u5b9e\u5c31\u662f\u628a\u521a\u624d\u8bbe\u7f6e\u7684\u89c4\u5219\u5199\u5165\u5230 \/etc\/sysconfig\/iptables \u6587\u4ef6\u4e2d\u3002<br \/>\n6\u3001DNS\u7aef\u53e353\u8bbe\u7f6e<br \/>\n\u4e0b\u9762\u6211\u4eec\u6765\u770b\u770b\u5982\u4f55\u8bbe\u7f6eiptables\u6765\u6253\u5f00DNS\u7aef\u53e3\uff0cDNS\u7aef\u53e3\u5bf9\u5e94\u7684\u662f53<\/p>\n<p>\u5927\u5bb6\u770b\u5230\u6211\u73b0\u5728\u7684\u60c5\u51b5\u4e86\u5427\uff0c\u53ea\u5f00\u653e22\u548c80\u7aef\u53e3\uff0c \u6211\u73b0\u5728\u770b\u770b\u80fd\u4e0d\u80fd\u89e3\u6790\u57df\u540d\u3002<\/p>\n<p>host www.google.com \u8f93\u5165\u8fd9\u4e2a\u547d\u4ee4\u540e\uff0c\u4e00\u76f4\u7b49\u5f85\uff0c\u8bf4\u660eDNS\u4e0d\u901a<\/p>\n<p>\u51fa\u73b0\u4e0b\u9762\u63d0\u793a \uff1a<br \/>\n;; connection timed out; no servers could be reached<\/p>\n<p>ping \u4e00\u4e0b\u57df\u540d\u4e5f\u662f\u4e0d\u901a<br \/>\n[root@localhost ~<strong>ping www.google.com<\/strong><br \/>\nping: unknown host www.google.com<\/p>\n<p>\u6211\u8fd9\u91cc\u7684\u539f\u56e0\u5c31\u662f iptables \u9650\u5236\u4e8653\u7aef\u53e3\u3002<\/p>\n<p>\u6709\u4e9b\u670d\u52a1\u5668\uff0c\u7279\u522b\u662fWeb\u670d\u52a1\u5668\u51cf\u6162\uff0cDNS\u5176\u5b9e\u4e5f\u6709\u5173\u7cfb\u7684\uff0c\u65e0\u6cd5\u53d1\u9001\u5305\u5230DNS\u670d\u52a1\u5668\u5bfc\u81f4\u7684\u3002<\/p>\n<p>\u4e0b\u9762\u6f14\u793a\u4e0b\u5982\u4f55\u4f7f\u7528 iptables \u6765\u8bbe\u7f6eDNS 53\u8fd9\u4e2a\u7aef\u53e3\uff0c\u5982\u679c\u4f60\u4e0d\u77e5\u9053 \u57df\u540d\u670d\u52a1\u7aef\u53e3\u53f7\uff0c\u4f60<\/p>\n<p>\u53ef\u4ee5\u7528\u547d\u4ee4 : <strong>grep domain \/etc\/services<\/strong><\/p>\n<p>[root@localhost ~grep domain \/etc\/services<br \/>\ndomain\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 53\/tcp\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 # name-domain server<br \/>\ndomain\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 53\/udp<br \/>\ndomaintime\u00a0\u00a0\u00a0\u00a0\u00a0 9909\/tcp\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 # domaintime<br \/>\ndomaintime\u00a0\u00a0\u00a0\u00a0\u00a0 9909\/udp\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 # domaintime<\/p>\n<p>\u770b\u5230\u4e86\u5427\uff0c \u6211\u4eec\u4e00\u822c\u4f7f\u7528 udp \u534f\u8bae\u3002<\/p>\n<p>\u597d\u4e86\uff0c \u5f00\u59cb\u8bbe\u7f6e\u3002\u3002\u3002<\/p>\n<p><strong> iptables -A OUTPUT -p udp \u2013dport 53 -j ACCEPT<\/strong><br \/>\n\u8fd9\u662f\u6211\u4eec ping \u4e00\u4e2a\u57df\u540d\uff0c\u6570\u636e\u5c31\u662f\u4ece\u672c\u673a\u51fa\u53bb\uff0c\u6240\u4ee5\u6211\u4eec\u5148\u8bbe\u7f6e OUTPUT\uff0c<br \/>\n\u6211\u4eec\u6309\u7167ping\u8fd9\u4e2a\u6d41\u7a0b\u6765\u8bbe\u7f6e\u3002<\/p>\n<p>\u7136\u540e DNS \u670d\u52a1\u5668\u6536\u5230\u6211\u4eec\u53d1\u51fa\u53bb\u7684\u5305\uff0c\u5c31\u56de\u5e94\u4e00\u4e2a\u56de\u6765<br \/>\n<strong>iptables -A INPUT -p udp \u2013sport 53 -j ACCEPT<\/strong><\/p>\n<p>\u540c\u65f6\u8fd8\u8981\u8bbe\u7f6e<br \/>\n<strong>\u00a0\u00a0\u00a0 iptables -A INPUT -p udp \u2013dport 53 -j ACCEPT<br \/>\niptables -A OUTPUT -p udp \u2013sport 53 -j ACCEPT<\/strong><\/p>\n<p>\u597d\u4e86\uff0c \u4e0b\u9762\u5f00\u59cb\u6d4b\u8bd5\u4e0b\uff0c \u53ef\u4ee5\u7528 iptables -L -n \u67e5\u770b\u8bbe\u7f6e\u60c5\u51b5\uff0c\u786e\u5b9a\u6ca1\u6709\u95ee\u9898\u5c31\u53ef\u4ee5\u6d4b\u8bd5\u4e86<\/p>\n<p>[root@localhost ~<strong>iptables -L -n<\/strong><br \/>\nChain INPUT (policy DROP)<br \/>\ntarget\u00a0\u00a0\u00a0\u00a0 prot opt source\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destination<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp dpt:22<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp dpt:80<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 udp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 udp spt:53<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 udp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 udp dpt:53<\/p>\n<p>Chain FORWARD (policy DROP)<br \/>\ntarget\u00a0\u00a0\u00a0\u00a0 prot opt source\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destination<\/p>\n<p>Chain OUTPUT (policy DROP)<br \/>\ntarget\u00a0\u00a0\u00a0\u00a0 prot opt source\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destination<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp spt:22 state ESTABLISHED<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp spt:80 state ESTABLISHED<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 udp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 udp dpt:53<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 udp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 udp spt:53<\/p>\n<p>\u53ef\u4ee5\u6d4b\u8bd5\u4e00\u4e0b \u662f\u5426 DNS \u53ef\u4ee5\u901a\u8fc7iptables \u4e86\u3002<\/p>\n<p>[root@localhost ~<strong>host www.google.com<\/strong><br \/>\nwww.google.com is an alias for www.l.google.com.<br \/>\nwww.l.google.com is an alias for www-china.l.google.com.<br \/>\nwww-china.l.google.com has address 64.233.189.104<br \/>\nwww-china.l.google.com has address 64.233.189.147<br \/>\nwww-china.l.google.com has address 64.233.189.99<\/p>\n<p>\u6b63\u5e38\u53ef\u4ee5\u89e3\u6790 google \u57df\u540d\u3002<\/p>\n<p>ping \u65b9\u9762\u53ef\u80fd\u8fd8\u8981\u8bbe\u7f6e\u4e9b\u4e1c\u897f\u3002<\/p>\n<p>\u7528 nslookup \u770b\u770b\u5427<\/p>\n<p>[root@localhost ~<strong>nslookup<\/strong><br \/>\n&gt; www.google.com<br \/>\nServer:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 192.168.1.1<br \/>\nAddress:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 192.168.1.1#53<\/p>\n<p>Non-authoritative answer:<br \/>\nwww.google.com canonical name = www.l.google.com.<br \/>\nwww.l.google.com canonical name = www-china.l.google.com.<br \/>\nName:\u00a0\u00a0 www-china.l.google.com<br \/>\nAddress: 64.233.189.147<br \/>\nName:\u00a0\u00a0 www-china.l.google.com<br \/>\nAddress: 64.233.189.99<br \/>\nName:\u00a0\u00a0 www-china.l.google.com<br \/>\nAddress: 64.233.189.104<\/p>\n<p>\u8bf4\u660e\u672c\u673aDNS\u6b63\u5e38\uff0c iptables \u5141\u8bb853\u8fd9\u4e2a\u7aef\u53e3\u7684\u8bbf\u95ee\u3002<br \/>\n7\u3001iptables\u5bf9ftp\u7684\u8bbe\u7f6e<br \/>\n\u73b0\u5728\u6211\u5f00\u59cb\u5bf9ftp\u7aef\u53e3\u7684\u8bbe\u7f6e\uff0c\u6309\u7167\u6211\u4eec\u4ee5\u524d\u7684\u89c6\u9891\uff0c\u6dfb\u52a0\u9700\u8981\u5f00\u653e\u7684\u7aef\u53e3<br \/>\nftp\u8fde\u63a5\u7aef\u53e3\u67092\u4e2a 21 \u548c 20 \u7aef\u53e3\uff0c\u6211\u73b0\u5728\u6dfb\u52a0\u5bf9\u5e94\u7684\u89c4\u5219\u3002<\/p>\n<p>[root@localhost root<strong>iptables -A INPUT -p tcp \u2013dport 21 -j ACCEPT<\/strong><br \/>\n[root@localhost root<strong>iptables -A INPUT -p tcp \u2013dport 20 -j ACCEPT<\/strong><br \/>\n[root@localhost root<strong>iptables -A OUTPUT -p tcp \u2013sport 21 -j ACCEPT<\/strong><br \/>\n[root@localhost root<strong>iptables -A OUTPUT -p tcp \u2013sport 20 -j ACCEPT<\/strong><\/p>\n<p>\u597d\uff0c\u8fd9\u6837\u5c31\u6dfb\u52a0\u5b8c\u4e86\uff0c\u6211\u4eec\u7528\u6d4f\u89c8\u5668\u8bbf\u95ee\u4e00\u4e0bftp,\u51fa\u73b0\u8d85\u65f6\u3002<\/p>\n<p>\u6240\u4ee5\u6211\u521a\u624d\u8bf4 ftp \u662f\u6bd4\u8f83\u7279\u6b8a\u7684\u7aef\u53e3\uff0c\u5b83\u8fd8\u6709\u4e00\u4e9b\u7aef\u53e3\u662f \u6570\u636e\u4f20\u8f93\u7aef\u53e3\uff0c<br \/>\n\u4f8b\u5982\u76ee\u5f55\u5217\u8868\uff0c \u4e0a\u4f20 \uff0c\u4e0b\u8f7d \u6587\u4ef6\u90fd\u8981\u7528\u5230\u8fd9\u4e9b\u7aef\u53e3\u3002<\/p>\n<p>\u800c\u8fd9\u4e9b\u7aef\u53e3\u662f \u4efb\u610f \u7aef\u53e3\u3002\u3002\u3002 \u8fd9\u4e2a \u4efb\u610f \u771f\u7684\u6bd4\u8f83\u7279\u6b8a\u3002<\/p>\n<p>\u5982\u679c\u4e0d\u6307\u5b9a\u4ec0\u4e48\u4e00\u4e2a\u7aef\u53e3\u8303\u56f4\uff0c iptables \u5f88\u96be\u5bf9\u4efb\u610f\u7aef\u53e3\u5f00\u653e\u7684\uff0c<br \/>\n\u5982\u679ciptables\u5141\u8bb8\u4efb\u610f\u7aef\u53e3\u8bbf\u95ee\uff0c \u90a3\u548c\u4e0d\u8bbe\u7f6e\u9632\u706b\u5899\u6ca1\u4ec0\u4e48\u533a\u522b\uff0c\u6240\u4ee5\u4e0d\u73b0\u5b9e\u7684\u3002<\/p>\n<p>\u90a3\u4e48\u6211\u4eec\u7684\u89e3\u51b3\u529e\u6cd5\u5c31\u662f \u6307\u5b9a\u8fd9\u4e2a\u6570\u636e\u4f20\u8f93\u7aef\u53e3\u7684\u4e00\u4e2a\u8303\u56f4\u3002<\/p>\n<p>\u4e0b\u9762\u6211\u4eec\u4fee\u6539\u4e00\u4e0bftp\u914d\u7f6e\u6587\u4ef6\u3002<\/p>\n<p>\u6211\u8fd9\u91cc\u4f7f\u7528vsftpd\u6765\u4fee\u6539\u6f14\u793a\uff0c\u5176\u4ed6ftp\u6211\u4e0d\u77e5\u9053\u54ea\u91cc\u4fee\u6539\uff0c\u5927\u5bb6\u53ef\u4ee5\u627e\u627e\u8d44\u6599\u3002<\/p>\n<p>[root@localhost root<strong>vi \/etc\/vsftpd.conf<\/strong><\/p>\n<p>\u5728\u914d\u7f6e\u6587\u4ef6\u7684\u6700\u4e0b\u9762 \u52a0\u5165<\/p>\n<p>pasv_min_port=30001<br \/>\npasv_max_port=31000<\/p>\n<p>\u7136\u540e\u4fdd\u5b58\u9000\u51fa\u3002<\/p>\n<p>\u8fd9\u4e24\u53e5\u8bdd\u7684\u610f\u601d\u544a\u8bc9vsftpd, \u8981\u4f20\u8f93\u6570\u636e\u7684\u7aef\u53e3\u8303\u56f4\u5c31\u572830001\u523031000 \u8fd9\u4e2a\u8303\u56f4\u5185\u4f20\u9001\u3002<\/p>\n<p>\u8fd9\u6837\u6211\u4eec\u4f7f\u7528 iptables \u5c31\u597d\u529e\u591a\u4e86\uff0c\u6211\u4eec\u5c31\u6253\u5f00 30001\u523031000 \u8fd9\u4e9b\u7aef\u53e3\u3002<\/p>\n<p>[root@localhost root<strong>iptables -A INPUT -p tcp \u2013dport 30001:31000 -j ACCEPT<\/strong><br \/>\n[root@localhost root<strong>iptables -A OUTPUT -p tcp \u2013sport 30001:31000 -j ACCEPT<\/strong><\/p>\n<p>[root@localhost root<strong>service iptables save<\/strong><\/p>\n<p>\u6700\u540e\u8fdb\u884c\u4fdd\u5b58\uff0c \u7136\u540e\u6211\u4eec\u518d\u7528\u6d4f\u89c8\u5668\u8303\u56f4\u4e0b ftp\u3002\u53ef\u4ee5\u6b63\u5e38\u8bbf\u95ee<\/p>\n<p>\u7528\u4e2a\u8d26\u53f7\u767b\u9646\u4e0a\u53bb\uff0c\u4e5f\u6ca1\u6709\u95ee\u9898\uff0c\u4e0a\u4f20\u4e00\u4e9b\u6587\u4ef6\u4e0a\u53bb\u770b\u770b\u3002<\/p>\n<p>\u770b\u5230\u4e86\u5427\uff0c\u4e0a\u4f20\u548c\u4e0b\u8f7d\u90fd\u6b63\u5e38\u3002\u3002 \u518d\u67e5\u770b\u4e0b iptables \u7684\u8bbe\u7f6e<\/p>\n<p>[root@localhost root<strong>iptables -L -n<\/strong><br \/>\nChain INPUT (policy DROP)<br \/>\ntarget\u00a0\u00a0\u00a0\u00a0 prot opt source\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destination<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp dpt:22<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp dpt:21<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp dpt:20<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp dpts:30001:31000<\/p>\n<p>Chain FORWARD (policy DROP)<br \/>\ntarget\u00a0\u00a0\u00a0\u00a0 prot opt source\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destination<\/p>\n<p>Chain OUTPUT (policy DROP)<br \/>\ntarget\u00a0\u00a0\u00a0\u00a0 prot opt source\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destination<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp spt:22<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp spt:21<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp spt:20<br \/>\nACCEPT\u00a0\u00a0\u00a0\u00a0 tcp\u00a0 \u2013\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.0.0.0\/0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 tcp spts:30001:31000<\/p>\n<p>\u8fd9\u662f\u6211\u4e3a\u4e86\u6f14\u793aftp\u7279\u6b8a\u7aef\u53e3\u505a\u7684\u7b80\u5355\u89c4\u5219\uff0c\u5927\u5bb6\u53ef\u4ee5\u6dfb\u52a0\u4e00\u4e9b\u5bf9\u6570\u636e\u5305\u7684\u9a8c\u8bc1<br \/>\n\u4f8b\u5982 <strong>-m state \u2013state ESTABLISHED,RELATED<\/strong>\u00a0 \u7b49\u7b49\u8981\u6c42\u66f4\u52a0\u9ad8\u7684\u9a8c\u8bc1<\/p>\n","protected":false},"excerpt":{"rendered":"<p>1\u3001\u5173\u95ed\u6240\u6709\u7684 INPUT FORWARD OUTPUT \u53ea\u5bf9\u67d0\u4e9b\u7aef\u53e3\u5f00\u653e\u3002 \u4e0b\u9762\u662f\u547d\u4ee4\u5b9e\u73b0\uff1a iptable [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[23,100],"class_list":["post-358","post","type-post","status-publish","format-standard","hentry","category-linux","tag-centos","tag-iptables"],"_links":{"self":[{"href":"http:\/\/blog.sway.com.cn\/index.php?rest_route=\/wp\/v2\/posts\/358","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/blog.sway.com.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blog.sway.com.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blog.sway.com.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/blog.sway.com.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=358"}],"version-history":[{"count":2,"href":"http:\/\/blog.sway.com.cn\/index.php?rest_route=\/wp\/v2\/posts\/358\/revisions"}],"predecessor-version":[{"id":360,"href":"http:\/\/blog.sway.com.cn\/index.php?rest_route=\/wp\/v2\/posts\/358\/revisions\/360"}],"wp:attachment":[{"href":"http:\/\/blog.sway.com.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=358"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blog.sway.com.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=358"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blog.sway.com.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=358"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}