{"id":20566,"date":"2026-07-09T11:10:27","date_gmt":"2026-07-09T03:10:27","guid":{"rendered":"https:\/\/blog.ywdevops.cn\/?p=20566"},"modified":"2026-07-14T12:17:56","modified_gmt":"2026-07-14T04:17:56","slug":"iptables","status":"publish","type":"post","link":"https:\/\/blog.ywdevops.cn\/index.php\/2026\/07\/09\/iptables\/","title":{"rendered":"iptables\u7528\u6cd5"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u4e00\u3001<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u5e95\u5c42\u57fa\u7840\uff1aNetfilter &amp; iptables<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1\u3001<strong>Netfilter<\/strong>\uff1aLinux \u5185\u6838\u5185\u7f6e\u7f51\u7edc\u9632\u706b\u5899\u6846\u67b6\uff0c\u63d0\u4f9b 5 \u4e2a\u6570\u636e\u5305\u62e6\u622a\u94a9\u5b50\u70b9\uff08\u4e94\u94fe\uff09\uff0c\u771f\u6b63\u5904\u7406\u6570\u636e\u5305<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">2\u3001<strong>iptables<\/strong>\uff1a\u7528\u6237\u6001\u547d\u4ee4\u884c\u5de5\u5177\uff0c\u7528\u6765\u7ed9 Netfilter \u914d\u7f6e\u89c4\u5219\uff0c\u53ea\u662f\u914d\u7f6e\u5165\u53e3<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">3\u3001\u4e09\u5c42\u7ed3\u6784\uff1a<strong>\u8868 (table) \u2192 \u94fe (chain) \u2192 \u89c4\u5219 (rule)<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8868\uff1a\u6309\u529f\u80fd\u5206\u7c7b\u89c4\u5219\u96c6\u5408<\/li>\n\n\n\n<li>\u94fe\uff1a\u6570\u636e\u5305\u5fc5\u7ecf\u7684\u62e6\u622a\u70b9\uff08\u94a9\u5b50\uff09<\/li>\n\n\n\n<li>\u89c4\u5219\uff1a\u5339\u914d\u6761\u4ef6 + \u6267\u884c\u52a8\u4f5c\uff0c\u4ece\u4e0a\u5230\u4e0b\u9010\u6761\u5339\u914d\uff0c\u5339\u914d\u5373\u7ec8\u6b62\uff1b\u65e0\u5339\u914d\u8d70\u94fe\u9ed8\u8ba4\u7b56\u7565<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><code>iptables<\/code> \u91cc\u9762\u6709\u4e24\u4e2a\u6982\u5ff5\u5bb9\u6613\u6df7\u6dc6\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u8868\uff08table\uff09<\/strong>\uff1a\u8d1f\u8d23\u4e0d\u540c\u7c7b\u578b\u7684\u6570\u636e\u5305\u5904\u7406\u529f\u80fd<\/li>\n\n\n\n<li><strong>\u94fe\uff08chain\uff09<\/strong>\uff1a\u6570\u636e\u5305\u7ecf\u8fc7\u7684\u5904\u7406\u8282\u70b9<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">iptables \u4e94\u5f20\u8868\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u8868\uff08table\uff09<\/th><th>\u4f5c\u7528<\/th><th>\u5e38\u7528\u573a\u666f<\/th><\/tr><\/thead><tbody><tr><td><strong>filter<\/strong><\/td><td>\u8fc7\u6ee4\u6570\u636e\u5305\uff08\u5141\u8bb8\/\u62d2\u7edd\uff09<\/td><td>\u9632\u706b\u5899\u89c4\u5219<\/td><\/tr><tr><td><strong>nat<\/strong><\/td><td>\u5730\u5740\u8f6c\u6362<\/td><td>SNAT\u3001DNAT\u3001\u7aef\u53e3\u8f6c\u53d1<\/td><\/tr><tr><td><strong>mangle<\/strong><\/td><td>\u4fee\u6539\u6570\u636e\u5305<\/td><td>\u4fee\u6539\u6807\u8bb0\u3001TTL\u3001QoS<\/td><\/tr><tr><td><strong>raw<\/strong><\/td><td>\u4f18\u5148\u7ea7\u6700\u9ad8\uff0c\u7ed5\u8fc7\u8fde\u63a5\u8ddf\u8e2a<\/td><td>NOTRACK<\/td><\/tr><tr><td><strong>security<\/strong><\/td><td>SELinux \u5b89\u5168\u7b56\u7565<\/td><td>SELinux<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">iptables \u4e94\u6761\u5185\u7f6e\u94fe\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u94fe<\/th><th>\u65b9\u5411<\/th><th>\u4f5c\u7528<\/th><\/tr><\/thead><tbody><tr><td><strong>PREROUTING<\/strong><\/td><td>\u8fdb\u5165\u672c\u673a\u4e4b\u524d<\/td><td>\u8def\u7531\u5224\u65ad\u524d<\/td><\/tr><tr><td><strong>INPUT<\/strong><\/td><td>\u8fdb\u5165\u672c\u673a<\/td><td>\u672c\u673a\u63a5\u6536<\/td><\/tr><tr><td><strong>FORWARD<\/strong><\/td><td>\u7ecf\u8fc7\u672c\u673a\u8f6c\u53d1<\/td><td>\u8def\u7531\u8f6c\u53d1<\/td><\/tr><tr><td><strong>OUTPUT<\/strong><\/td><td>\u672c\u673a\u4ea7\u751f<\/td><td>\u672c\u673a\u53d1\u51fa<\/td><\/tr><tr><td><strong>POSTROUTING<\/strong><\/td><td>\u79bb\u5f00\u672c\u673a\u4e4b\u524d<\/td><td>\u8def\u7531\u4e4b\u540e<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e25\u683c\u6765\u8bf4\uff1a \u4e94\u6761\u94fe\u5c5e\u4e8e\u4e0d\u540c\u8868\u7684\u7ec4\u5408\uff0c\u4e0d\u662f\u6bcf\u5f20\u8868\u90fd\u6709\u4e94\u6761<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e8c\u3001<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u5404\u8868\u6709\u54ea\u4e9b\u94fe\uff1f<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1\u3001filter \u8868\uff08\u9ed8\u8ba4\u8868\uff09\uff0c\u8d1f\u8d23\u9632\u706b\u5899<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>filter\n \u251c\u2500\u2500 INPUT\n \u251c\u2500\u2500 FORWARD\n \u2514\u2500\u2500 OUTPUT<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f8b\u5982\uff1a \u653e\u884cSSH\u7aef\u53e3<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -p tcp --dport 22 -j ACCEPT<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">2\u3001nat \u8868(Network Address Translation\uff0c\u7f51\u7edc\u5730\u5740\u8f6c\u6362\u8868)<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>nat\n \u251c\u2500\u2500 PREROUTING\n \u251c\u2500\u2500 INPUT\n \u251c\u2500\u2500 OUTPUT\n \u2514\u2500\u2500 POSTROUTING<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>PREROUTING\uff1a\u6570\u636e\u5305<strong>\u8fdb\u5165\u8def\u7531\u51b3\u7b56\u4e4b\u524d<\/strong>\u5904\u7406\uff0c\u5e38\u7528\u4e8e <strong>DNAT\uff08\u76ee\u7684\u5730\u5740\u8f6c\u6362\uff09<\/strong>\u3001\u7aef\u53e3\u6620\u5c04<\/li>\n\n\n\n<li>INPUT\uff1a\u8fdb\u5165<strong>\u672c\u673a\u8fdb\u7a0b<\/strong>\u7684\u6570\u636e\u5305\uff08nat \u8868\u4e2d\u7528\u5f97\u5f88\u5c11\uff0c\u67d0\u4e9b\u7279\u6b8a\u573a\u666f\u624d\u4f1a\u7528\u5230\uff09<\/li>\n\n\n\n<li>OUTPUT\uff1a<strong>\u672c\u673a\u53d1\u51fa<\/strong>\u7684\u6570\u636e\u5305\uff0c\u5728\u8def\u7531\u524d\u5904\u7406\uff0c\u5e38\u7528\u4e8e\u5bf9\u672c\u673a\u8bbf\u95ee\u5916\u7f51\u7684 <strong>DNAT<\/strong><\/li>\n\n\n\n<li>POSTROUTING\uff1a\u6570\u636e\u5305<strong>\u79bb\u5f00\u672c\u673a\u524d\u3001\u8def\u7531\u51b3\u7b56\u4e4b\u540e<\/strong>\u5904\u7406\uff0c\u6700\u5e38\u7528\uff0c\u7528\u4e8e <strong>SNAT\uff08\u6e90\u5730\u5740\u8f6c\u6362\uff09<\/strong>\u3001MASQUERADE\uff08\u5982\u4e0a\u7f51 NAT\uff09<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f8b\u5982\uff1aDNAT(\u76ee\u6807\u5730\u5740\u8f6c\u6362)\uff0c\u5916\u90e8IP\uff1a8080 => \u5185\u7f51\uff1a80<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 8080 -j DNAT --to-destination 192.168.1.100:80\r<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>-i eth0<\/code>\uff1a\u6307\u5b9a\u5916\u7f51\u5165\u7f51\u5361<\/li>\n\n\n\n<li><code>--dport 9090<\/code>\uff1a\u5bf9\u5916\u66b4\u9732\u7684\u516c\u7f51\u7aef\u53e3<\/li>\n\n\n\n<li>&#8211;to-destination \u5185\u7f51IP:\u5185\u7f51\u7aef\u53e3<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">SNAT\uff08\u6e90\u5730\u5740\u8f6c\u6362\uff09\uff0c\u5185\u7f51\u8bbf\u95ee\u516c\u7f51\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t nat -A POSTROUTING -d 192.168.1.100 -p tcp --dport 80 -j SNAT --to-source 203.0.113.100\r<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">3\u3001mangle\u8868\uff1a<strong>\u4e13\u95e8\u7528\u6765\u4fee\u6539 \/ \u6807\u8bb0\u6570\u636e\u5305\u672c\u8eab\u5c5e\u6027\u7684\u8868<\/strong>\uff0c\u53ef\u4ee5\u6539\u5199\u6570\u636e\u5305\u5934\u90e8\u4fe1\u606f\u3001\u6253\u8fde\u63a5\u6807\u8bb0\uff0c\u7528\u4e8e\u8def\u7531\u3001QoS\u3001\u6d41\u91cf\u63a7\u5236\u3001\u7b56\u7565\u8def\u7531\u3001\u4f18\u5316\u7f51\u7edc\u53c2\u6570\u7b49\u573a\u666f\uff0c<strong>\u4e0d\u662f\u505a\u5e38\u89c4\u9632\u706b\u5899\u653e\u884c \/ \u963b\u65ad\uff0c\u4e5f\u4e0d\u662f\u505a\u5730\u5740 NAT \u8f6c\u6362<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mangle\r\n \u251c\u2500\u2500 PREROUTING\r\n \u251c\u2500\u2500 INPUT\r\n \u251c\u2500\u2500 FORWARD\r\n \u251c\u2500\u2500 OUTPUT\r\n \u2514\u2500\u2500 POSTROUTING<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4fee\u6539\u6570\u636e\u5305 TTL\uff08\u751f\u5b58\u65f6\u95f4\uff09\uff0c<code>--ttl-set<\/code> \/ <code>--ttl-dec<\/code> \/ <code>--ttl-inc<\/code>\uff0c\u7edf\u4e00 TTL \u503c\u3001\u9632\u6b62\u8fd0\u8425\u5546\u68c0\u6d4b \/ \u9650\u5236\u5171\u4eab\u4e0a\u7f51<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t mangle -A POSTROUTING -o eth0 -j TTL --ttl-set 64\r<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4fee\u6539\u6570\u636e\u5305 DSCP \u503c\uff0c\u533a\u5206\u8bed\u97f3 \/ \u89c6\u9891 \/ \u666e\u901a\u6570\u636e\uff0c\u914d\u5408 tc \u6d41\u91cf\u9650\u901f\u3001\u5e26\u5bbd\u4f18\u5148\u7ea7<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t mangle -A PREROUTING -p udp --dport 5060 -j DSCP --set-dscp 46\r<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">MARK \u6253\u6570\u636e\u5305\u6807\u8bb0\uff0c\u4f7f\u7528<code>-j MARK --set-mark \u6570\u503c<\/code> \uff0c\u6807\u8bb0\u672c\u8eab<strong>\u4e0d\u4f1a\u6539\u6570\u636e\u5305\u539f\u59cb\u62a5\u6587<\/strong>\uff0c\u4ec5\u5728\u5185\u6838\u91cc\u505a\u5185\u5b58\u6807\u8bb0<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t mangle -A PREROUTING -p tcp --dport 80 -j MARK --set-mark 10\r<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4fee\u6539 TCP \u9009\u9879\u3001MSS\uff08\u6700\u5927\u5206\u6bb5\u5927\u5c0f\uff09<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t mangle -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu\r<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u65e5\u5e38\u9700\u6c42\uff1a\u5f00\u653e\u7aef\u53e3\u3001\u9632\u626b\u63cf\u3001\u57fa\u7840\u9632\u62a4\u3001\u7b80\u5355\u7aef\u53e3\u6620\u5c04\u2192 \u53ea\u7528 filter + nat \u8868\u5c31\u8db3\u591f\uff0c\u5982\u679c\u662f\u7f51\u5173 \/ \u8f6f\u8def\u7531 \/ \u591a\u7ebf\u670d\u52a1\u5668 \/ \u505a\u7cbe\u7ec6\u6d41\u91cf\u7ba1\u63a7\uff1a\u9ad8\u9891\u4f7f\u7528<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">4\u3001raw\u8868<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>raw\r\n \u251c\u2500\u2500 PREROUTING\r\n \u2514\u2500\u2500 OUTPUT<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u666e\u901a\u5355\u7f51\u5361 Web \/ \u6570\u636e\u5e93\u670d\u52a1\u5668\uff1a\u9ed8\u8ba4\u7a7a raw \u8868\u5373\u53ef\uff0c\u65e5\u5e38\u57fa\u672c\u4e0d\u7528<\/li>\n\n\n\n<li>\u7f51\u5173\u3001\u8f6f\u8def\u7531\u3001\u9ad8\u5e76\u53d1\u6d41\u91cf\u670d\u52a1\u5668\uff1a\u5f88\u5e38\u7528\uff0c\u7528\u6765\u505a\u6027\u80fd\u4f18\u5316<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">5\u3001security\u8868\uff0c<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u5e73\u65f6\u5f88\u5c11\u76f4\u63a5\u64cd\u4f5c<\/mark><\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>security\r\n \u251c\u2500\u2500 INPUT\r\n \u251c\u2500\u2500 FORWARD\r\n \u2514\u2500\u2500 OUTPUT<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e09\u3001\u6570\u636e\u5305\u7ecf\u8fc7\u987a\u5e8f\uff0c\u5047\u8bbe\u5916\u90e8\u8bbf\u95ee\u4f60\u7684Linux\u670d\u52a1\u5668<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>            Linux\u7f51\u5361\r\n             |\r\n            \u2193\r\n       PREROUTING\r\n             |\r\n        \u8def\u7531\u5224\u65ad\r\n          \/    \\\r\n         \/      \\\r\n     \u672c\u673a       \u8f6c\u53d1\r\n      |          |\r\n     \u2193         \u2193\r\n   INPUT      FORWARD\r\n      |\r\n   \u5e94\u7528\u7a0b\u5e8f\r\n      |\r\n   OUTPUT\r\n      |\r\n POSTROUTING\r\n      |\r\n     \u2193\r\n     \u7f51\u5361<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8bf4\u660e\uff1a\u5047\u5982\u670d\u52a1\u5668\u516c\u7f51\u4e2aIP\u4e3a\uff1a 34.100.5.68\uff0c\u5916\u90e8\u7a0b\u5e8f\u8bbf\u95ee34.100.5.68:8080\uff0c\u6d41\u7a0b\u5982\u4e0b\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5916\u90e8\u7a0b\u5e8f\u8bf7\u6c42\u5230\u8fbe\u7f51\u5361\uff0c\u6bd4\u5982eth0\uff0c\u6b64\u65f6\u6570\u636e\u5305\u8fd8\u6ca1\u5230iptables\u89c4\u5219<\/li>\n\n\n\n<li>\u5230\u8fbePREROUTING\uff1a\u6267\u884cDNAT\uff0c\u5c0634.100.5.68:8080 \u53d8\u6210\u5185\u7f51:80\uff0c\u901a\u8fc7iptables -t nat \u5b9e\u73b0<\/li>\n\n\n\n<li>\u5230\u8fbe\u8def\u7531\u5224\u65ad\uff1a\u5224\u65ad\u76ee\u6807\u6570\u636e\u5305\u662f\u4e0d\u662f\u7ed9\u672c\u673a\uff0c\u5982\u679c\u662f\u7ed9\u672c\u673a\uff0c\u76f4\u63a5\u8d70INPUT<\/li>\n\n\n\n<li>\u5224\u65ad\u76ee\u6807IP\u5730\u5740\u4e0d\u662f\u672c\u673a\uff0c\u8d70FORWARD\u94fe\u8fdb\u884c\u8f6c\u53d1<\/li>\n\n\n\n<li>OUTPUT\uff1a\u7528\u4e8e\u672c\u673a\u670d\u52a1\u5668\u8bf7\u6c42\u5916\u9762\u7684\u6570\u636e\uff0c\u4e0d\u7ecf\u8fc7PREROUTING\uff0c\u4f46\u662f\u51fa\u53bb\u4e4b\u524d\u8981\u7ecf\u8fc7POSTROUTING<\/li>\n\n\n\n<li>POSTROUTING\uff1a \u5e38\u7528\u4e8eSNAT\uff0c\u6bd4\u5982\u6211\u7684\u5185\u7f51\u673a\u5668\u8981\u8bbf\u95ee\u4e92\u8054\u7f51\u76848.8.8.8\uff0c\u51fa\u53bb\u4e4b\u524dPOSTROUTING\u628a\u5185\u7f51IP\u53d8\u4e3a\u516c\u7f51IP\uff0c\u7136\u540e\u901a\u8fc7\u8fd9\u4e2a\u516c\u7f51IP\u53bb\u5916\u9762\u8bf7\u6c42\uff0c\u89c4\u5219\u53ef\u4ee5\u914d\u7f6e<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u52a8\u6001\u5730\u5740\u4f2a\u88c5<\/mark><\/strong>\u548c<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u9759\u6001\u6e90\u5730\u5740\u8f6c\u6362<\/mark><\/strong>\uff0c\u5982\u4e0b<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">MASQUERADE\uff08\u52a8\u6001\u5730\u5740\u4f2a\u88c5\uff09\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t nat -A POSTROUTING \\\r\n  -s 192.168.1.0\/24 \\\r\n  -o eth0 \\\r\n  -j MASQUERADE<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6bcf\u6b21\u53d1\u5305\u90fd <strong>\u67e5\u5f53\u524d\u51fa\u53e3\u7f51\u5361\u7684 IP<\/strong><\/li>\n\n\n\n<li>\u4e0d\u5173\u5fc3 IP \u662f\u591a\u5c11\uff0c\u81ea\u52a8\u7528\u201c\u73b0\u5728\u7684\u90a3\u4e2a\u201d<\/li>\n\n\n\n<li>\u9002\u5408\uff1a<strong>IP \u53ef\u80fd\u53d8\u3001\u61d2\u5f97\u7ef4\u62a4\u89c4\u5219<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u7279\u70b9\uff1a\u914d\u7f6e\u7b80\u5355\u3001\u62d4\u7ebf\u91cd\u8fde \/ IP \u53d8\u4e86\u4e5f\u4e0d\u7528\u6539\u89c4\u5219\u5185\u6838\u8981\u591a\u505a\u4e00\u6b21\u5730\u5740\u67e5\u627e\uff08\u6027\u80fd\u7565\u4f4e\uff0c\u4f46\u4e00\u822c\u611f\u77e5\u4e0d\u5230\uff09<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">SNAT\uff08\u9759\u6001\u6e90\u5730\u5740\u8f6c\u6362\uff09\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t nat -A POSTROUTING \\\r\n  -s 192.168.1.0\/24 \\\r\n  -o eth0 \\\r\n  -j SNAT --to-source  34.100.5.68<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u660e\u786e\u5199\u6b7b<\/strong>\u8f6c\u6362\u540e\u7684\u6e90 IP<\/li>\n\n\n\n<li>\u5185\u6838\u76f4\u63a5\u66ff\u6362\uff0c\u4e0d\u8d70\u52a8\u6001\u67e5\u8be2<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u7279\u70b9\uff1a\u6027\u80fd\u6700\u597d\u884c\u4e3a\u786e\u5b9a\uff0c\u9002\u5408\u751f\u4ea7\u73af\u5883\u3001\u5927\u6d41\u91cf\u3001\u516c\u7f51 IP \u4e00\u53d8\uff0c\u89c4\u5219\u5c31\u5931\u6548\uff0c\u5fc5\u987b\u624b\u52a8\u6539<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u603b\u7ed3\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u51fa\u53e3 IP \u4f1a\u53d8\uff08DHCP \/ PPPoE \/ \u4e91\u4e3b\u673a\u5f39\u6027 IP\uff09\u2192 \u7528 MASQUERADE<\/li>\n\n\n\n<li>\u51fa\u53e3 IP \u56fa\u5b9a\uff08IDC \u9759\u6001\u516c\u7f51 IP\uff09\u2192 \u7528 SNAT<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u5e38\u7528iptables\u89c4\u5219<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1\u3001\u67e5\u770b\u9ed8\u8ba4filter\u8868<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t filter -L -n\niptables -L -n -v --line-number   #\u589e\u5f3a\u7248<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">2\u3001\u67e5\u770b\u6240\u6709\u8868\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t filter -L -n    #filter\u8868\niptables -t nat -L -n       #nat\u8868\niptables -t mangle -L -n    #mangle\u8868\niptables -t raw -L -n       #raw\u8868<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">3\u3001\u67e5\u770b\u89c4\u5219\u7f16\u53f7\uff0c<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u975e\u5e38\u5e38\u7528<\/mark><\/strong>\uff0c\u5220\u9664\u7684\u65f6\u5019\u9700\u8981\u7f16\u53f7\uff0c\u4e0b\u65b9\u5220\u9664\u89c4\u5219\u91cc\u6709\u5220\u9664\u7528\u6cd5<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -L INPUT -n --line-number<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">4\u3001\u67e5\u770b\u89c4\u5219\u7edf\u8ba1\uff0c\u770b\u547d\u4e2d\u6b21\u6570\uff0c\u6d41\u91cf\u5927\u5c0f\uff0c\u5224\u65ad\u89c4\u5219\u662f\u5426\u751f\u6548<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -L -v -n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f8b\u5982\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>pkts bytes\r\n1000 2M<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">5\u3001\u94fe\u9ed8\u8ba4\u7b56\u7565<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -S<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"649\" height=\"196\" src=\"https:\/\/blog.ywdevops.cn\/wp-content\/uploads\/2026\/07\/2-1.png\" alt=\"\" class=\"wp-image-20620\" srcset=\"https:\/\/blog.ywdevops.cn\/wp-content\/uploads\/2026\/07\/2-1.png 649w, https:\/\/blog.ywdevops.cn\/wp-content\/uploads\/2026\/07\/2-1-300x91.png 300w, https:\/\/blog.ywdevops.cn\/wp-content\/uploads\/2026\/07\/2-1-600x181.png 600w\" sizes=\"auto, (max-width: 649px) 100vw, 649px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">6\u3001\u8bbe\u7f6e\u9ed8\u8ba4\u7b56\u7565<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -P INPUT ACCEPT     #\u5141\u8bb8\niptables -P INPUT DROP       #\u62d2\u7edd<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u751f\u4ea7\u73af\u5883\u5e38\u89c1\u7b56\u7565\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -P INPUT DROP\r\niptables -P FORWARD DROP\r\niptables -P OUTPUT ACCEPT<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">7\u3001\u6e05\u7a7a\u89c4\u5219<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -F                 #\u6e05\u7a7afilter\u94fe\niptables -F INPUT           #\u6e05\u7a7a\u6307\u5b9a\u94fe\niptables -X                 #\u5220\u9664\u81ea\u5b9a\u4e49\u94fe\niptables -t nat -F          #\u6e05\u7a7anat<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6e05\u7a7a\u6240\u6709\u89c4\u5219\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -F\r\niptables -t nat -F\r\niptables -t mangle -F\r\niptables -X<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">8\u3001\u5f00\u653e\u7aef\u53e3(<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-purple-color\">\u6700\u5e38\u7528<\/mark><\/strong>)<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -p tcp --dport 22 -j ACCEPT        #\u5f00\u653e22\u7aef\u53e3\niptables -A INPUT -p tcp -dport 80 -j ACCEPT         #\u5f00\u653ehttp\niptables -A INPUT -p tcp --dport 443 -j ACCEPT       #\u5f00\u653ehttps\niptables -A INPUT -p tcp -m multiport --dports 22,80,443 -j ACCEPT #\u5f00\u653e\u591a\u4e2a\u7aef\u53e3<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">9\u3001\u9650\u5236\u6765\u6e90IP<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ea\u5141\u8bb8192.168.51.100\u6267\u884cSSH\u8fde\u63a5\u5230\u672c\u673a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -s 192.168.51.100 -p tcp --dport 22 -j ACCEPT\niptables -P INPUT DROP<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7981\u6b62\u67d0IP<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -s 1.2.3.4 -j DROP<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7981\u6b62\u7f51\u6bb5<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -s 10.0.0.0\/8 -j DROP<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">10\u3001\u5141\u8bb8\u5df2\u5efa\u7acb\u8fde\u63a5(\u751f\u4ea7\u5fc5\u5907)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5df2\u7ecf\u5efa\u7acb\u7684TCP\u8fde\u63a5\u7ee7\u7eed\u5141\u8bb8\uff0c\u6bd4\u5982SSH\u767b\u5f55\u540e\uff0c\u4e0d\u4f1a\u56e0\u4e3a\u540e\u9762\u7684DROP\u88ab\u65ad\u5f00<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">11\u3001\u5141\u8bb8\u672c\u673alocalhost\u8bbf\u95ee<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -i lo -j ACCEPT<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">12\u3001Ping\u63a7\u5236<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -p icmp -j ACCEPT        #\u5141\u8bb8ping\niptables -A INPUT -p icmp -j DROP          #\u7981\u6b62ping<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">13\u3001\u65e5\u5fd7\u8bb0\u5f55<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -j LOG --log-prefix \"iptables-drop:\"     #\u8bb0\u5f55\u4e22\u5f03\u5305\ndmesg | grep iptables \u6216 journalctl -k                     #\u67e5\u770b\u65e5\u5fd7<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">14\u3001NAT\u5e38\u7528<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">SNAT\uff1a\u5185\u7f51\u8bbf\u95ee\u516c\u7f51<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t nat -A POSTROUTING -s 192.168.1.0\/24 -j MASQUERADE   #\u52a8\u6001\u5730\u5740\u8f6c\u6362\n\u6216\niptables -t nat -A POSTROUTING -s 192.168.1.0\/24 -o eth0 -j SNAT --to-source \u516c\u7f51IP  #\u9759\u6001\u6e90\u5730\u5740\u8f6c\u6362<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">DNAT\uff1a\u7aef\u53e3\u8f6c\u53d1\uff0c\u516c\u7f51\uff1a8080 ==> \u5185\u7f51\uff1a80<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t nat -A PREROUTING -p tcp --dport 8080 -j DNAT --to-destination 192.168.1.10:80<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u672c\u673a\u7aef\u53e3\u8f6c\u53d1\uff0c\u672c\u673a\uff1a8080 ==> \u672c\u673a\uff1a80<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -t nat -A OUTPUT -p tcp --dport 8080 -j REDIRECT --to-port 80<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">15\u3001\u9650\u5236\u8fde\u63a5\u6570\u91cf<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u9650\u5236SSH\u6570\u91cf\u4e3a5\uff0c\u6700\u591a\u53ea\u67095\u4e2a\u8fde\u63a5<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -p tcp --dport 22 -m connlimit --connlimit-above 5 -j DROP<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">16\u3001\u9632SYN Flood<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -A INPUT -p tcp --syn -m limit --limit 10\/s -j ACCEPT<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">17\u3001\u5220\u9664\u89c4\u5219\uff0c \u5148\u67e5\u770b<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -L INPUT -n --line-number    #\u53ef\u4ee5\u83b7\u53d6\u5230\u7f16\u53f7<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f8b\u5982\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>1 ACCEPT tcp dpt:22\r\n2 DROP tcp dpt:80<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5220\u9664\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables -D INPUT 2<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">18\u3001\u4fdd\u5b58\u89c4\u5219\uff0cubuntu\u7cfb\u7edf\u4e3a\u4f8b\u5b50<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>iptables-save > \/etc\/iptables\/rules.v4        #\u4fdd\u5b58\niptables-restore &lt; \/etc\/iptables\/rules.v4     #\u6062\u590d<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u4e00\u3001\u5e95\u5c42\u57fa\u7840\uff1aNetfilter &amp; iptables 1\u3001Netfilter\uff1aLinux \u5185\u6838\u5185\u7f6e\u7f51 [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":20568,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[],"class_list":["post-20566","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-linux"],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":8}},"_links":{"self":[{"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/posts\/20566","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/comments?post=20566"}],"version-history":[{"count":45,"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/posts\/20566\/revisions"}],"predecessor-version":[{"id":20637,"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/posts\/20566\/revisions\/20637"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/media\/20568"}],"wp:attachment":[{"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/media?parent=20566"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/categories?post=20566"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.ywdevops.cn\/index.php\/wp-json\/wp\/v2\/tags?post=20566"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}