{"id":2118,"date":"2021-01-28T16:52:25","date_gmt":"2021-01-28T08:52:25","guid":{"rendered":"http:\/\/www.menshours.com\/?p=2118"},"modified":"2021-01-28T19:33:33","modified_gmt":"2021-01-28T11:33:33","slug":"linux-iptables-%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/www.menshours.com\/index.php\/2021\/01\/28\/linux-iptables-%e8%af%a6%e8%a7%a3\/","title":{"rendered":"Linux iptables \u8be6\u89e3"},"content":{"rendered":"\n

Linux iptables <\/strong>\u8be6\u89e3<\/strong><\/strong><\/p>\n\n\n\n

\uff08\u4e00\uff09- \u56db\u8868\/\u4e94\u94fe\u3001\u6570\u636e\u5305\u5339\u914d\u6d41\u7a0b\u3001\u7f16\u5199 iptables \u89c4\u5219<\/strong><\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

1.Linux <\/strong>\u9632\u706b\u5899\u57fa\u7840<\/strong><\/strong><\/p>\n\n\n\n

Linux\u9632\u706b\u5899\u4e3b\u8981\u5de5\u4f5c\u5728\u7f51\u7edc\u5c42\uff0c\u9488\u5bf9 TCP\/IP \u6570\u636e\u5305\u5b9e\u65bd\u8fc7\u6ee4\u548c\u9650\u5236\uff0c\u5178\u578b\u7684\u5305\u8fc7\u6ee4\u9632\u706b\u5899\uff0c\u57fa\u4e8e\u5185\u6838\u7f16\u7801\u5b9e\u73b0\uff0c\u5177\u6709\u975e\u5e38\u7a33\u5b9a\u7684\u6027\u80fd\u548c\u9ad8\u6548\u7387\u3002<\/p>\n\n\n\n

  • iptables\uff1a\u7528\u6765\u7ba1\u7406 Linux \u9632\u706b\u5899\u7684\u547d\u4ee4\u7a0b\u5e8f\uff0c\u4f4d\u4e8e\/sbin\/iptables\u76ee\u5f55\u4e0b\uff0c\u5c5e\u4e8e\u7528\u6237\u7a7a\u95f4\u7684\u9632\u706b\u5899\u7ba1\u7406\u4f53\u7cfb\u3002<\/li>
  • netfilter\uff1aLinux \u5185\u6838\u4e2d\u5b9e\u73b0\u5305\u8fc7\u6ee4\u9632\u706b\u5899\u7684\u5185\u90e8\u7ed3\u6784\uff0c\u4e00\u822c\u4e0d\u4ee5\u7a0b\u5e8f\u6216\u6587\u4ef6\u7684\u5f62\u5f0f\u5b58\u5728\uff0c\u5c5e\u4e8e\u5185\u6838\u7a7a\u95f4\u7684\u9632\u706b\u5899\u7ba1\u7406\u4f53\u7cfb\u3002<\/li><\/ul>\n\n\n\n

    iptables \u7684\u4f5c\u7528\uff1a\u4e3a\u5305\u8fc7\u6ee4\u673a\u5236\u7684\u5b9e\u73b0\u63d0\u4f9b\u89c4\u5219\uff0c\u901a\u8fc7\u5404\u79cd\u4e0d\u540c\u7684\u89c4\u5219\uff0c\u6765\u544a\u8bc9netfilter\u5bf9\u6765\u81ea\u67d0\u4e9b\u6e90\u4ee5\u53ca\u524d\u5f80\u67d0\u4e9b\u76ee\u7684\u6216\u5177\u6709\u67d0\u4e9b\u534f\u8bae\u7279\u5f81\u7684\u6570\u636e\u5305\u662f\u5982\u4f55\u8fdb\u884c\u5904\u7406\u7684\u3002<\/p>\n\n\n\n

    2.iptables <\/strong>\u7684\u8868\u3001\u94fe\u7ed3\u6784<\/strong><\/strong><\/p>\n\n\n\n

    \u6bcf\u4e2a\u89c4\u5219\u8868\uff0c\u5176\u5b9e\u5c31\u76f8\u5f53\u4e8e\u4e00\u4e2a\u5185\u6838\u7a7a\u95f4\u7684\u5bb9\u5668\uff0c\u6309\u7167\u89c4\u5219\u96c6\u7684\u4e0d\u540c\u7528\u9014\u8fdb\u884c\u5212\u5206\u4e3a\u9ed8\u8ba4\u7684\u56db\u4e2a\u8868\uff0c\u5728\u6bcf\u4e2a\u89c4\u5219\u8868\u4e2d\u5305\u542b\u4e0d\u540c\u7684\u89c4\u5219\u94fe\uff0c\u5904\u7406\u6570\u636e\u5305\u7684\u4e0d\u540c\u65f6\u673a\u5206\u4e3a\u4e94\u79cd\u94fe\uff0c\u51b3\u5b9a\u662f\u5426\u8fc7\u6ee4\u6216\u5904\u7406\u6570\u636e\u5305\u7684\u5404\u79cd\u89c4\u5219\u5e76\u6309\u7167\u5148\u540e\u987a\u5e8f\u5b58\u653e\u5728\u5404\u89c4\u5219\u94fe\u4e2d\u3002<\/p>\n\n\n\n

    • \u89c4\u5219\u7684\u4f5c\u7528\uff1a\u5bf9\u6570\u636e\u5305\u8fdb\u884c\u8fc7\u6ee4\u6216\u5904\u7406\uff1b<\/li>
    • \u94fe\u7684\u4f5c\u7528\uff1a\u5bb9\u7eb3\u591a\u79cd\u9632\u706b\u5899\u89c4\u5219\uff1b<\/li><\/ul>\n\n\n\n
      \"\"<\/figure><\/div>\n\n\n\n

      \u89c4\u5219\u8868<\/strong><\/strong><\/p>\n\n\n\n

      iptables\u7ba1\u7406\u7740\u56db\u4e2a\u4e0d\u540c\u7684\u89c4\u5219\u8868\uff0c\u5206\u522b\u7531\u72ec\u7acb\u7684\u5185\u6838\u6a21\u5757\u5b9e\u73b0\u3002<\/p>\n\n\n\n

      • filter \u8868\uff1a\u7528\u6765\u5bf9\u6570\u636e\u5305\u8fdb\u884c\u8fc7\u6ee4\uff0c\u5177\u4f53\u7684\u89c4\u5219\u8981\u6c42\u51b3\u5b9a\u5982\u4f55\u5904\u7406\u4e00\u4e2a\u6570\u636e\u5305\u3002<\/li><\/ul>\n\n\n\n

        \u5bf9\u5e94\u7684\u5185\u6838\u6a21\u5757\u4e3a\uff1aiptable_filter\uff0c\u5176\u8868\u5185\u5305\u62ec\u4e09\u4e2a\u94fe\uff1ainput\u3001forward\u3001output;<\/p>\n\n\n\n

        • nat \u8868\uff1anat \u5168\u79f0\uff1anetwork address translation \u7f51\u7edc\u5730\u5740\u8f6c\u6362\uff0c\u4e3b\u8981\u7528\u6765\u4fee\u6539\u6570\u636e\u5305\u7684 IP \u5730\u5740\u3001\u7aef\u53e3\u53f7\u4fe1\u606f\u3002<\/li><\/ul>\n\n\n\n

          \u5bf9\u5e94\u7684\u5185\u6838\u6a21\u5757\u4e3a\uff1aiptable_nat\uff0c\u5176\u8868\u5185\u5305\u62ec\u4e09\u4e2a\u94fe\uff1aprerouting\u3001postrouting\u3001output;<\/p>\n\n\n\n

          • mangle \u8868\uff1a\u4e3b\u8981\u7528\u6765\u4fee\u6539\u6570\u636e\u5305\u7684\u670d\u52a1\u7c7b\u578b\uff0c\u751f\u5b58\u5468\u671f\uff0c\u4e3a\u6570\u636e\u5305\u8bbe\u7f6e\u6807\u8bb0\uff0c\u5b9e\u73b0\u6d41\u91cf\u6574\u5f62\u3001\u7b56\u7565\u8def\u7531\u7b49\u3002<\/li><\/ul>\n\n\n\n

            \u5bf9\u5e94\u7684\u5185\u6838\u6a21\u5757\u4e3a\uff1aiptable_mangle\uff0c\u5176\u8868\u5185\u5305\u62ec\u4e94\u4e2a\u94fe\uff1aprerouting\u3001postrouting\u3001input\u3001output\u3001forward;<\/p>\n\n\n\n

            • raw \u8868\uff1a\u4e3b\u8981\u7528\u6765\u51b3\u5b9a\u662f\u5426\u5bf9\u6570\u636e\u5305\u8fdb\u884c\u72b6\u6001\u8ddf\u8e2a\u3002<\/li><\/ul>\n\n\n\n

              \u5bf9\u5e94\u7684\u5185\u6838\u6a21\u5757\u4e3a\uff1aiptable_raw\uff0c\u5176\u8868\u5185\u5305\u62ec\u4e24\u4e2a\u94fe\uff1aoutput\u3001prerouting;<\/p>\n\n\n\n

              \u89c4\u5219\u94fe<\/strong><\/strong><\/p>\n\n\n\n

              • input \u94fe\uff1a\u5f53\u6536\u5230\u8bbf\u95ee\u9632\u706b\u5899\u672c\u673a\u5730\u5740\u7684\u6570\u636e\u5305\u65f6\uff0c\u5c06\u5e94\u7528\u6b64\u94fe\u4e2d\u7684\u89c4\u5219\uff1b<\/li>
              • output \u94fe\uff1a\u5f53\u9632\u706b\u5899\u672c\u673a\u5411\u5916\u53d1\u9001\u6570\u636e\u5305\u65f6\uff0c\u5c06\u5e94\u7528\u6b64\u94fe\u4e2d\u7684\u89c4\u5219\uff1b<\/li>
              • forward \u94fe\uff1a\u5f53\u6536\u5230\u9700\u8981\u901a\u8fc7\u9632\u706b\u4e2d\u8f6c\u53d1\u7ed9\u5176\u4ed6\u5730\u5740\u7684\u6570\u636e\u5305\u65f6\uff0c\u5c06\u5e94\u7528\u6b64\u94fe\u4e2d\u7684\u89c4\u5219\uff1b<\/li>
              • prerouting \u94fe\uff1a\u5728\u5bf9\u6570\u636e\u5305\u505a\u8def\u7531\u9009\u62e9\u4e4b\u524d\uff0c\u5c06\u5e94\u7528\u6b64\u94fe\u4e2d\u7684\u89c4\u5219\uff1b<\/li>
              • postrouting \u94fe\uff1a\u5728\u5bf9\u6570\u636e\u5305\u505a\u8def\u7531\u9009\u62e9\u4e4b\u540e\uff0c\u5c06\u5e94\u7528\u6b64\u94fe\u4e2d\u7684\u89c4\u5219\uff1b<\/li><\/ul>\n\n\n\n

                input <\/strong>\u94fe<\/strong> <\/strong>\u548c<\/strong> output <\/strong>\u94fe\u4e3b\u8981\u7528\u5728\u4e3b\u673a\u578b\u9632\u706b\u5899\uff0c\u662f\u9488\u5bf9\u670d\u52a1\u5668\u672c\u673a\u8fdb\u884c\u4fdd\u62a4\u7684\u9632\u706b\u5899\uff1b<\/strong><\/strong><\/p>\n\n\n\n

                forward <\/strong>\u94fe\u3001<\/strong>prerouting <\/strong>\u94fe\u3001<\/strong>postrouting <\/strong>\u94fe\u4e3b\u8981\u7528\u5728\u7f51\u7edc\u578b\u9632\u706b\u5899\uff0c\u662f\u9488\u5bf9\u516c\u53f8\u5185\u7f51\u4e0e<\/strong> Internet <\/strong>\u4e4b\u95f4\u8fdb\u884c\u5b89\u5168\u63a7\u5236\u3002<\/strong><\/strong><\/p>\n\n\n\n

                3.\u6570\u636e\u5305\u8fc7\u6ee4\u7684\u5339\u914d\u6d41\u7a0b<\/strong><\/p>\n\n\n\n

                \"\"<\/figure>\n\n\n\n

                \u89c4\u5219\u8868\u4e4b\u95f4\u7684\u987a\u5e8f<\/strong><\/strong><\/p>\n\n\n\n

                \u5f53\u6570\u636e\u5305\u5230\u8fbe\u9632\u706b\u5899\u65f6\uff0c\u5982\u679c\u5bf9\u5e94\u7684\u94fe\u5185\u6709\u89c4\u5219\u5b58\u5728\uff0c\u5c06\u6309\u7167\u987a\u5e8f\u4f9d\u6b21\u4eceraw \u8868\u2192mangle \u8868\u2192nat \u8868\u2192filter \u8868\u3002<\/p>\n\n\n\n

                \u89c4\u5219\u94fe\u4e4b\u95f4\u7684\u987a\u5e8f<\/strong><\/strong><\/p>\n\n\n\n

                • \u5165\u6570\u636e\u6d41\u5411\uff1a\u5982\u679c\u662f\u5916\u8fb9\u7684\u6570\u636e\u5305\u5230\u8fbe\u9632\u706b\u5899\u540e\uff0c\u8981\u5148\u901a\u8fc7prerouting \u94fe\uff1a\u5bf9\u6570\u636e\u5305\u505a\u8def\u7531\u9009\u62e9\u4e4b\u540e\uff0c\u5c06\u5e94\u7528\u6b64\u94fe\u4e2d\u7684\u89c4\u5219\uff0c\u7136\u540e\u5c06\u8fdb\u884c\u8def\u7531\u9009\u62e9\uff0c\u786e\u8ba4\u6570\u636e\u5305\u7684\u76ee\u6807\u5730\u5740\u662f\u5426\u662f\u9632\u706b\u5899\u672c\u673a\uff0c\u7ed3\u5408\u5185\u6838\u4f20\u9001\u7ed9input\u94fe\u505a\u5904\u7406\uff0c\u786e\u8ba4\u901a\u8fc7\u4e4b\u540e\uff0c\u4fbf\u53ef\u4ee5\u4ea4\u7ed9\u670d\u52a1\u5668\u7aef\u6765\u8fdb\u884c\u54cd\u5e94\u3002<\/li>
                • \u8f6c\u53d1\u6570\u636e\u6d41\u5411\uff1a\u5982\u679c\u662f\u5916\u8fb9\u7684\u6570\u636e\u5305\u5230\u8fbe\u9632\u706b\u5899\u540e\uff0c\u8981\u5148\u901a\u8fc7prerouting \u94fe\u505a\u76f8\u5173\u5904\u7406\uff0c\u968f\u540e\u8fdb\u884c\u8def\u7531\u9009\u62e9\uff0c\u6570\u636e\u5305\u7684\u76ee\u6807\u5730\u5740\u662f\u4efb\u4f55\u5176\u4ed6\u5730\u5740\u7684\u8bdd\uff0c\u5219\u5c06\u901a\u8fc7\u5185\u6838\u4f20\u7ed9forward\u6765\u8fdb\u884c\u5904\u7406\u662f\u5426\u9700\u8981\u901a\u8fc7\u6216\u76f4\u63a5\u4e22\u5f03\uff0c\u6700\u540e\u5c06\u4ea4\u7ed9postrouting \u94fe\u6765\u67e5\u770b\u662f\u5426\u6709\u9700\u8981\u4fee\u6539\u7684\u6570\u636e\u5305\u4fe1\u606f\u6765\u8fdb\u884c\u5904\u7406\u3002<\/li>
                • \u51fa\u6570\u636e\u6d41\u5411\uff1a\u51fa\u6d41\u91cf\uff0c\u5176\u5b9e\u5c31\u662f\u9632\u706b\u5899\u672c\u673a\u5411\u5916\u7684\u5730\u5740\u53d1\u9001\u6570\u636e\u5305\uff0c\u9996\u5148\u88aboutput \u94fe\u5904\u7406\uff0c\u7136\u540e\u9009\u62e9\u8def\u7531\uff0c\u7136\u540e\u5728postrouting \u94fe\u67e5\u770b\u662f\u5426\u4fee\u6539\u6570\u636e\u5305\u7684\u4fe1\u606f\u6765\u8fdb\u884c\u5904\u7406\u3002<\/li><\/ul>\n\n\n\n

                  \u89c4\u5219\u94fe\u5185\u90e8\u5404\u6761\u9632\u706b\u5899\u89c4\u5219\u4e4b\u95f4\u7684\u987a\u5e8f<\/strong><\/strong><\/p>\n\n\n\n

                  \u6570\u636e\u5305\u7ecf\u8fc7\u6bcf\u6761\u89c4\u5219\u94fe\u65f6\uff0c\u5c06\u6309\u7167\u7b2c\u4e00\u6761\u89c4\u5219\u3001\u7b2c\u4e8c\u6761\u89c4\u5219\u2026\u2026\u7684\u987a\u5e8f\u8fdb\u884c\u5339\u914d\u548c\u5904\u7406\u3002<\/p>\n\n\n\n

                  \u94fe\u5185\u7684\u8fc7\u6ee4\u539f\u5219<\/strong><\/strong><\/p>\n\n\n\n

                  • \u5c06\u6309\u7167\u4ece\u5339\u914d\u5230\u505c\u6b62\u7684\u65b9\u5f0f\uff0c\u5982\u627e\u5230\u4e00\u6761\u5339\u914d\u7684\u89c4\u5219\uff0c\u5c06\u4e0d\u518d\u6267\u884c\u672c\u94fe\u4e2d\u540e\u7eed\u7684\u5176\u4ed6\u89c4\u5219\uff1b<\/li>
                  • \u5982\u679c\u5bf9\u6bd4\u6574\u4e2a\u94fe\u4e5f\u627e\u4e0d\u5230\u4e0e\u6570\u636e\u5305\u76f8\u5339\u914d\u7684\u89c4\u5219\u65f6\uff0c\u5c06\u6309\u7167\u8be5\u89c4\u5219\u94fe\u7684\u9ed8\u8ba4\u7b56\u7565\u8fdb\u884c\u5904\u7406\uff1b<\/li><\/ul>\n\n\n\n

                    4.<\/strong>\u7f16\u5199\u9632\u706b\u5899\u89c4\u5219<\/strong><\/strong><\/p>\n\n\n\n

                    iptables <\/strong>\u7684\u57fa\u672c\u8bed\u6cd5\u547d\u4ee4\u683c\u5f0f<\/strong><\/strong><\/p>\n\n\n\n

                    iptables [-t \u8868\u540d] \u7ba1\u7406\u9009\u9879 [\u94fe\u540d] [\u5339\u914d\u6761\u4ef6] [-j \u63a7\u5236\u7c7b\u578b]<\/p>\n\n\n\n

                    • \u8868\u540d\u3001\u94fe\u540d\uff1a\u6307\u5b9aiptables\u547d\u4ee4\u6240\u64cd\u4f5c\u7684\u8868\u548c\u94fe\uff0c\u672a\u6307\u5b9a\u8868\u540d\u65f6\u5c06\u9ed8\u8ba4\u4f7f\u7528filter\u8868\uff1b<\/li>
                    • \u7ba1\u7406\u9009\u9879\uff1a\u8868\u793aiptables\u89c4\u5219\u7684\u64cd\u4f5c\u65b9\u5f0f\uff0c\u6bd4\u5982\uff1a\u63d2\u5165\u3001\u589e\u52a0\u3001\u5220\u9664\u3001\u67e5\u770b\u7b49\uff1b<\/li>
                    • \u5339\u914d\u6761\u4ef6\uff1a\u6307\u5b9a\u8981\u5904\u7406\u7684\u6570\u636e\u5305\u7684\u7279\u5f81\uff0c\u4e0d\u7b26\u5408\u6307\u5b9a\u6761\u4ef6\u7684\u6570\u636e\u5305\u4e0d\u5728\u5904\u7406\uff1b<\/li>
                    • \u63a7\u5236\u7c7b\u578b\uff1a\u6307\u6570\u636e\u5305\u7684\u5904\u7406\u65b9\u5f0f\uff0c\u6bd4\u5982\uff1a\u5141\u8bb8\u3001\u62d2\u7edd\u3001\u4e22\u5f03\u7b49\uff1b<\/li><\/ul>\n\n\n\n

                      iptables <\/strong>\u9632\u706b\u5899\u6700\u5e38\u7528\u7684\u63a7\u5236\u7c7b\u578b<\/strong><\/strong><\/p>\n\n\n\n

                      • accept\uff1a\u5141\u8bb8\u6570\u636e\u5305\uff1b<\/li>
                      • drop\uff1a\u4e22\u5f03\u6570\u636e\u5305\uff0c\u4e14\u4e0d\u7ed9\u4efb\u4f55\u56de\u5e94\u4fe1\u606f\uff1b<\/li>
                      • reject\uff1a\u62d2\u7edd\u6570\u636e\u5305\uff0c\u5fc5\u8981\u65f6\u4f1a\u7ed9\u6570\u636e\u53d1\u9001\u7aef\u4e00\u4e2a\u54cd\u5e94\u4fe1\u606f\uff1b<\/li>
                      • log\uff1a\u5728\/var\/log\/messages\u6587\u4ef6\u4e2d\u8bb0\u5f55\u65e5\u5fd7\u4fe1\u606f\uff0c\u7136\u540e\u5c06\u6570\u636e\u5305\u4f20\u9012\u7ed9\u4e0b\u4e00\u4e2a\u5730\u5740\uff1b<\/li><\/ul>\n\n\n\n

                        iptables <\/strong>\u9632\u706b\u5899\u7684\u6700\u5e38\u7528\u57fa\u672c\u64cd\u4f5c<\/strong><\/strong><\/p>\n\n\n\n

                        iptables \u547d\u4ee4\u7684\u5e38\u7528\u7ba1\u7406\u9009\u9879

                        -A:\u5728\u6307\u5b9a\u94fe\u7684\u672b\u5c3e\u6dfb\u52a0\u4e00\u6761\u65b0\u7684\u89c4\u5219
                        -D:\u5220\u9664\u6307\u5b9a\u94fe\u4e2d\u7684\u67d0\u4e00\u6761\u89c4\u5219\uff0c\u53ef\u5220\u9664\u6307\u5b9a\u5e8f\u53f7\u6216\u5177\u4f53\u5185\u5bb9
                        -I:\u5728\u6307\u5b9a\u94fe\u4e2d\u63d2\u5165\u4e00\u6761\u65b0\u89c4\u5219\uff0c\u672a\u6307\u5b9a\u5e8f\u53f7\u65f6\u9ed8\u8ba4\u4f5c\u4e3a\u7b2c\u4e00\u6761\u89c4\u5219
                        -R:\u4fee\u6539\u3001\u66ff\u6362\u6307\u5b9a\u94fe\u4e2d\u7684\u67d0\u4e00\u6761\u89c4\u5219\uff0c\u53ef\u6307\u5b9a\u89c4\u5219\u5e8f\u53f7\u6216\u5177\u4f53\u5185\u5bb9
                        -L:\u5217\u51fa\u6307\u5b9a\u94fe\u4e2d\u6240\u6709\u7684\u89c4\u5219\uff0c\u672a\u6307\u5b9a\u94fe\u540d\uff0c\u5219\u5217\u51fa\u8868\u4e2d\u7684\u6240\u6709\u94fe
                        -F:\u6e05\u7a7a\u6307\u5b9a\u94fe\u4e2d\u6240\u6709\u7684\u89c4\u5219\uff0c\u672a\u6307\u5b9a\u94fe\u540d\uff0c\u5219\u6e05\u7a7a\u8868\u4e2d\u7684\u6240\u6709\u94fe
                        -P:\u8bbe\u7f6e\u6307\u5b9a\u94fe\u7684\u9ed8\u8ba4\u7b56\u7565
                        -n:\u4f7f\u7528\u6570\u5b57\u5f62\u5f0f\u663e\u793a\u8f93\u51fa\u7ed3\u679c
                        -v:\u67e5\u770b\u89c4\u5219\u5217\u8868\u65f6\u663e\u793a\u8be6\u7ec6\u7684\u4fe1\u606f
                        -h:\u67e5\u770b\u547d\u4ee4\u5e2e\u52a9\u4fe1\u606f
                        –line-numbers:\u67e5\u770b\u89c4\u5219\u5217\u8868\u65f6\uff0c\u540c\u65f6\u663e\u793a\u89c4\u5219\u5728\u94fe\u4e2d\u7684\u987a\u5e8f\u597d<\/p>\n\n\n\n

                        \u6dfb\u52a0\u65b0\u7684\u89c4\u5219<\/strong><\/strong><\/p>\n\n\n\n

                        \u6dfb\u52a0\u65b0\u7684\u9632\u706b\u5899\u89c4\u5219\u65f6\uff0c\u53ef\u4f7f\u7528\u7ba1\u7406\u9009\u9879-A\uff1a\u7528\u6765\u8ffd\u52a0\u89c4\u5219-l\uff1a\u7528\u6765\u63d2\u5165\u89c4\u5219\uff1b<\/p>\n\n\n\n

                        \u5728filter \u8868 INPUT \u94fe\u7684\u672b\u5c3e\u6dfb\u52a0\u4e00\u6761\u89c4\u5219\uff0c\u53ef\u4f7f\u7528-p\u534f\u8bae\u540d\u6765\u505a\u5339\u914d\u6761\u4ef6\uff1b<\/p>\n\n\n\n

                        # iptables -t filter -A INPUT -p tcp -j ACCEPT<\/p>\n\n\n\n

                        \u4f7f\u7528\u7ba1\u7406\u9009\u9879-I\uff0c\u5141\u8bb8\u540c\u65f6\u5236\u5b9a\u6dfb\u52a0\u89c4\u5219\u7684\u987a\u5e8f\u53f7\uff0c\u672a\u6307\u5b9a\u5e8f\u53f7\u65f6\u9ed8\u8ba4\u4f5c\u4e3a\u7b2c\u4e00\u6761\u89c4\u5219\uff1b<\/p>\n\n\n\n

                        \u6dfb\u52a0\u4e24\u6761\u89c4\u5219\u5206\u522b\u4f4d\u4e8efilter\u8868\u7684\u7b2c\u4e00\u6761\u3001\u7b2c\u4e8c\u6761\uff0c\u5c06\u4f7f\u7528\u9ed8\u8ba4\u7684filter\u8868\uff1b<\/p>\n\n\n\n

                        # iptables -I INPUT -p udp -j ACCEPT
                        # iptables -I INPUT 2 -p icmp -j ACCEPT<\/p>\n\n\n\n

                        \u67e5\u770b\u89c4\u5219\u5217\u8868<\/strong><\/strong><\/p>\n\n\n\n

                        \u67e5\u770b\u9632\u706b\u5899\u89c4\u5219\u65f6\uff0c\u9700\u4f7f\u7528\u7ba1\u7406\u9009\u9879-L\u5e76\u7ed3\u5408–line-numbers\u9009\u9879\u663e\u793a\u5404\u6761\u89c4\u5219\u5728\u94fe\u5185\u7684\u987a\u5e8f\u53f7\uff1b<\/p>\n\n\n\n

                        \u67e5\u770bfilter \u8868 INPUT \u94fe\u4e2d\u7684\u6240\u6709\u89c4\u5219\uff0c\u5e76\u663e\u793a\u89c4\u5219\u5e8f\u53f7\uff1b<\/p>\n\n\n\n

                        # iptables -L INPUT –line-numbers
                        Chain INPUT (policy ACCEPT)
                        num  target     prot opt source               destination         
                        1    ACCEPT     udp  —  anywhere             anywhere            
                        2    ACCEPT     icmp —  anywhere             anywhere            
                        3    ACCEPT     all  —  anywhere             anywhere            state RELATED,ESTABLISHED 
                        4    ACCEPT     icmp —  anywhere             anywhere            
                        5    ACCEPT     all  —  anywhere             anywhere            
                        6    ACCEPT     tcp  —  anywhere             anywhere            state NEW tcp dpt:ssh 
                        7    REJECT     all  —  anywhere             anywhere            reject-with icmp-host-prohibited 
                        8    ACCEPT     tcp  —  anywhere             anywhere            <\/p>\n\n\n\n

                        \u9632\u706b\u5899\u89c4\u5219\u591a\u65f6\uff0c\u53ef\u4ee5\u4ee5\u6570\u5b57\u5f62\u5f0f\u663e\u793a\u5730\u5740\u548c\u7aef\u53e3\u4fe1\u606f\uff0c\u51cf\u5c11\u5730\u5740\u89e3\u6790\u7684\u8fc7\u7a0b\uff0c\u52a0\u5feb\u547d\u4ee4\u7684\u6267\u884c\u901f\u5ea6\u3002<\/p>\n\n\n\n

                        \u4ee5\u6570\u5b57\u5f62\u5f0f\u67e5\u770b\u9ed8\u8ba4\u8868INPUT \u94fe\u4e2d\u7684\u6240\u6709\u89c4\u5219\uff0c\u53ef\u7ed3\u5408\u53c2\u6570-nL\u6216\u8005\u62c6\u5206-n -L\u7684\u65b9\u5f0f\u6765\u64cd\u4f5c;<\/p>\n\n\n\n

                        # iptables -nL INPUT
                        Chain INPUT (policy ACCEPT)
                        target     prot opt source               destination         
                        ACCEPT     udp  —  0.0.0.0\/0            0.0.0.0\/0           
                        ACCEPT     icmp —  0.0.0.0\/0            0.0.0.0\/0           
                        ACCEPT     all  —  0.0.0.0\/0            0.0.0.0\/0           state RELATED,ESTABLISHED 
                        ACCEPT     icmp —  0.0.0.0\/0            0.0.0.0\/0           
                        ACCEPT     all  —  0.0.0.0\/0            0.0.0.0\/0           
                        ACCEPT     tcp  —  0.0.0.0\/0            0.0.0.0\/0           state NEW tcp dpt:22 
                        REJECT     all  —  0.0.0.0\/0            0.0.0.0\/0           reject-with icmp-host-prohibited 
                        ACCEPT     tcp  —  0.0.0.0\/0            0.0.0.0\/0           <\/p>\n\n\n\n

                        \u5220\u9664\u3001\u6e05\u7a7a\u89c4\u5219<\/strong><\/strong><\/p>\n\n\n\n

                        \u5220\u9664filter \u8868 INPUT \u94fe\u4e2d\u7684\u7b2c\u4e09\u6761\u89c4\u5219\uff0c\u53ef\u4f7f\u7528\u7ba1\u7406\u9009\u9879-D\u6765\u5220\u9664\u4e00\u6761\u9632\u706b\u5899\u89c4\u5219\uff1b<\/p>\n\n\n\n

                        # iptables -D INPUT 3
                        # iptables -n -L INPUT<\/p>\n\n\n\n

                        \u6e05\u7a7a\u6307\u5b9a\u94fe\u6216\u8868\u4e2d\u7684\u6240\u6709\u9632\u706b\u5899\u89c4\u5219\uff0c\u53ef\u4f7f\u7528\u7ba1\u7406\u9009\u9879-F;<\/p>\n\n\n\n

                        # iptables -F INPUT
                        # iptables -n -L INPUT
                        Chain INPUT (policy ACCEPT)
                        target     prot opt source               destination  <\/p>\n\n\n\n

                        \u7701\u7565\u94fe\u540d\u800c\u6e05\u7a7a\u6307\u5b9a\u8868\u6240\u6709\u94fe\u7684\u89c4\u5219\uff0c\u53ef\u4f7f\u7528\u7ba1\u7406\u9009\u9879-F;<\/p>\n\n\n\n

                        # iptables -F
                        # iptables -t nat -F
                        # iptables -t mangle -F<\/p>\n\n\n\n

                        \u8bbe\u7f6e\u9ed8\u8ba4\u7b56\u7565<\/strong><\/strong><\/p>\n\n\n\n

                        \u9ed8\u8ba4\u7b56\u7565\u7684\u63a7\u5236\u7c7b\u578b\u5206\u4e3a\uff1aaccept\u3001drop\u4e24\u79cd\u3002<\/p>\n\n\n\n

                        \u5c06filter \u8868\u4e2d\u7684FORWARD \u94fe\u7684\u9ed8\u8ba4\u7b56\u7565\u8bbe\u7f6e\u4e3a\uff1a\u4e22\u5f03\uff0cOUTPUT \u94fe\u7684\u9ed8\u8ba4\u7b56\u7565\u8bbe\u7f6e\u4e3a\uff1a\u5141\u8bb8\uff1b<\/p>\n\n\n\n

                        # iptables -t filter -P FROWARD DROP
                        # iptables -P OUTPUT ACCEPT<\/p>\n\n\n\n

                        5.<\/strong>\u89c4\u5219\u7684\u5339\u914d\u6761\u4ef6<\/strong><\/strong><\/p>\n\n\n\n

                        \u901a\u7528\u5339\u914d\uff1a\u79f0\u4e3a\u5e38\u89c4\u5339\u914d\uff0c\u53ef\u72ec\u7acb\u4f7f\u7528\uff0c\u4e0d\u4f9d\u8d56\u4e8e\u5176\u4ed6\u6761\u4ef6\u6216\u6269\u5c55\u6a21\u5757\u3002<\/p>\n\n\n\n

                        \u534f\u8bae\u5339\u914d<\/strong><\/p>\n\n\n\n

                        \u7f16\u5199\u89c4\u5219\u65f6\u4f7f\u7528-p \u534f\u8bae\u540d\u7684\u5f62\u5f0f\u6307\u5b9a\uff1b<\/p>\n\n\n\n

                        \u7528\u6765\u68c0\u67e5\u6570\u636e\u5305\u6240\u4f7f\u7528\u7684\u7f51\u7edc\u534f\u8bae\uff0c\u53ef\u7528\u7684\u534f\u8bae\u7c7b\u578b\u6587\u4ef6\u4f4d\u4e8e\uff1a\/etc\/procotols\u4e2d\u3002<\/p>\n\n\n\n

                        # iptables -I INPUT -p icmp -j DROP
                        # iptables -A FORWARD ! -p icmp -j ACCEPT<\/p>\n\n\n\n

                        \u5730\u5740\u5339\u914d<\/strong><\/strong><\/p>\n\n\n\n

                        \u7f16\u5199iptables\u89c4\u5219\u65f6\u4f7f\u7528-s \u6e90\u5730\u5740\u6216-d \u76ee\u6807\u5730\u5740\u7684\u5f62\u5f0f\u6307\u5b9a\uff1b<\/p>\n\n\n\n

                        \u7528\u6765\u68c0\u67e5\u6570\u636e\u5305\u7684\u6e90\u5730\u5740\u6216\u76ee\u6807\u5730\u5740\u3002\uff08IP\u5730\u5740\u3001\u7f51\u6bb5\u5730\u5740\uff09<\/p>\n\n\n\n

                        \u4e0d\u5efa\u8bae\u4f7f\u7528\u4e3b\u673a\u540d\u3001\u57df\u540d\u5730\u5740\uff1b<\/strong><\/strong><\/p>\n\n\n\n

                        \u6bd4\u65b9\u8bf4\uff1a\u82e5\u8981\u62d2\u7edd\u8f6c\u53d1\u6e90\u5730\u5740\u4e3a 192.168.123.123 \u7684\u6570\u636e\uff0c\u4f46\u5141\u8bb8\u8f6c\u53d1\u6e90\u5730\u5740\u4f4d\u4e8e 192.168.1.0\/24 \u7f51\u6bb5\u7684\u6570\u636e\uff1b<\/p>\n\n\n\n

                        # iptables -A FORWARD -s 192.168.123.123 -j REJECT
                        # iptables -A FORWARD -s 192.168.1.0\/24 -j ACCEPT<\/p>\n\n\n\n

                        \u6bd4\u65b9\u8bf4\uff1a\u82e5\u8981\u68c0\u6d4b\u5230\u6765\u81ea\u67d0\u4e2a\u7f51\u7ad9\u7684\u9891\u7e41\u626b\u63cf\u3001\u767b\u5f55\u65f6\uff0c\u53ef\u6dfb\u52a0\u9632\u706b\u5899\u89c4\u5219\u8fdb\u884c\u5c01\u9501\uff1b<\/p>\n\n\n\n

                        # iptables -I INPUT -s 192.168.123.0\/24 -j DROP
                        # iptables -I FORWARD -s 192.168.123.0\/24 -j DROP<\/p>\n\n\n\n

                        \u7f51\u7edc\u63a5\u53e3\u5339\u914d<\/strong><\/strong><\/p>\n\n\n\n

                        \u7f16\u5199iptables\u89c4\u5219\u65f6\u4f7f\u7528-i \u63a5\u53e3\u540d\u548c-o \u63a5\u53e3\u540d\u7684\u5f62\u5f0f\u6307\u5b9a\uff1b<\/p>\n\n\n\n

                        \u7528\u6765\u68c0\u67e5\u6570\u636e\u5305\u4ece\u9632\u706b\u5899\u7684\u54ea\u4e00\u4e2a\u63a5\u53e3\u8fdb\u6216\u51fa\u7684\uff0c\u5e76\u4e14\u5206\u522b\u5bf9\u5e94\u5165\u7ad9\/\u51fa\u7ad9\u7f51\u5361\uff1b<\/p>\n\n\n\n

                        \u6bd4\u65b9\u8bf4\uff1a\u82e5\u8981\u4e22\u5f03\u4ece\u5916\u7f51\u63a5\u53e3\u8bbf\u95ee\u9632\u706b\u5899\u672c\u673a\u4e14\u6e90\u5730\u5740\u4e3a\u79c1\u6709\u5730\u5740\u7684\u6570\u636e\u5305\uff1b<\/p>\n\n\n\n

                        # iptables -A INPUT -i eth0 -s 10.0.0.0\/8 -j DROP
                        # iptables -A INPUT -i eth0 -s 172.16.0.0\/12 -j DROP
                        # iptables -A INPUT -i eth0 -s 192.168.0.0\/16 -j DROP<\/p>\n\n\n\n

                        \u9690\u542b\u5339\u914d\uff1a\u4ee5\u6307\u5b9a\u7684\u534f\u8bae\u5339\u914d\u4f5c\u4e3a\u524d\u63d0\u6761\u4ef6\uff0c\u5bf9\u5e94\u7684\u529f\u80fd\u7531iptables\u5728\u9700\u8981\u65f6\u81ea\u52a8\u9690\u542b\u8f7d\u5165\u5185\u6838\u3002<\/p>\n\n\n\n

                        \u5e38\u89c1\u7684\u9690\u542b\u5339\u914d\uff1a\u7aef\u53e3\u5339\u914d\u3001TCP\u5339\u914d\u3001ICMP\u5339\u914d\uff1b<\/p>\n\n\n\n

                        \u7aef\u53e3\u5339\u914d<\/strong><\/strong><\/p>\n\n\n\n

                        \u7f16\u5199iptables\u89c4\u5219\u65f6\u4f7f\u7528–sport \u6e90\u7aef\u53e3\u6216\u8005–dport \u76ee\u6807\u7aef\u53e3\u7684\u5f62\u5f0f\u6307\u5b9a\uff1b<\/p>\n\n\n\n

                        \u9488\u5bf9\u7684\u534f\u8bae\u7c7b\u578b\u4e3a\uff1aTCP\u3001UDP<\/p>\n\n\n\n

                        \u7528\u6765\u68c0\u67e5\u6570\u636e\u5305\u7684\u6e90\u7aef\u53e3\u6216\u76ee\u6807\u7aef\u53e3\u3002<\/p>\n\n\n\n

                        \u5355\u4e2a\u7aef\u53e3\u53f7\u6216\u8005\u4ee5\u5192\u53f7:\u5206\u9694\u7684\u7aef\u53e3\u8303\u56f4\u662f\u53ef\u4ee5\u63a5\u53d7\u7684\uff0c\u4f46\u4e0d\u8fde\u7eed\u7684\u591a\u4e2a\u7aef\u53e3\u662f\u4e0d\u53ef\u4ee5\u91c7\u7528\u7684\u3002<\/p>\n\n\n\n

                        \u6bd4\u65b9\u8bf4\uff1a\u5141\u8bb8\u4e3a\u7f51\u6bb5 192.168.123.0\/24 \u8f6c\u53d1 http \u67e5\u8be2\u6570\u636e\u5305\uff1b<\/p>\n\n\n\n

                        # iptables -A FORWARD -s 192.168.123.0\/24 -p udp –dport 80 -j ACCEPT
                        # iptables -A FORWARD -d 192.168.123.0\/24 -p udp –dport 80 -j ACCEPT<\/p>\n\n\n\n

                        \u6bd4\u65b9\u8bf4\uff1a\u642d\u5efa ftp \u670d\u52a1\u65f6\uff0c\u5f00\u653e 20\u300121 \u7aef\u53e3\uff0c\u4ee5\u53ca\u7528\u4e8e\u88ab\u52a8\u6a21\u5f0f\u7684\u7aef\u53e3\u8303\u56f4\u4e3a 24 100~25 200\uff1b<\/p>\n\n\n\n

                        # iptables -A INPUT -p tcp –dport 20:21 -j ACCEPT
                        # iptables -A INPUT -p tcp –dport 24100:25200 -j ACCEPT<\/p>\n\n\n\n

                        ICMP <\/strong>\u5339\u914d<\/strong><\/strong><\/p>\n\n\n\n

                        \u7f16\u5199iptables\u89c4\u5219\u65f6\u4f7f\u7528–icmp-type ICMP \u7c7b\u578b\u7684\u5f62\u5f0f\u6307\u5b9a\uff1b<\/p>\n\n\n\n

                        \u9488\u5bf9\u7684\u534f\u8bae\uff1aICMP\uff0c\u7528\u6765\u68c0\u67e5 ICMP \u6570\u636e\u5305\u7684\u7c7b\u578b\u3002<\/p>\n\n\n\n

                        ICMP \u7c7b\u578b\u4f7f\u7528\u5b57\u7b26\u4e32\u6216\u6570\u5b57\u663e\u793a<\/p>\n\n\n\n

                        • echo-request\uff1a8\uff08ICMP \u534f\u8bae\u8bf7\u6c42\uff09<\/li>
                        • echo-reply\uff1a0\uff08ICMP \u534f\u8bae\u56de\u663e\uff09<\/li>
                        • destination-unreachable\uff1a3\uff08ICMP \u534f\u8bae\u76ee\u6807\u4e0d\u53ef\u8fbe\uff09<\/li><\/ul>\n\n\n\n

                          \u6bd4\u65b9\u8bf4\uff1a\u82e5\u8981\u7981\u6b62\u4ece\u5176\u4ed6\u4e3b\u673a ping \u672c\u673a\uff0c\u4f46\u662f\u5141\u8bb8\u672c\u673a ping \u5176\u4ed6\u4e3b\u673a\u3002<\/p>\n\n\n\n

                          # iptables -A INPUT -p icmp –icmp-type 8 -j DROP
                          # iptables -A INPUT -p icmp –icmp-type 0 -j ACCEPT
                          # iptables -A INPUT -p icmp –icmp-type 3 -j ACCEPT
                          # iptables -A INPUT -p icmp -j DROP<\/p>\n\n\n\n

                          \u66f4\u591a\u53ef\u7528\u7684 ICMP \u534f\u8bae\u7c7b\u578b\uff0c\u53ef\u6267\u884ciptables -p icmp -h\u8fdb\u884c\u67e5\u770b\uff1b<\/p>\n\n\n\n

                          \u663e\u793a\u5339\u914d<\/strong><\/strong><\/p>\n\n\n\n

                          \u8be5\u5339\u914d\u65b9\u5f0f\u9700\u8981\u6709\u989d\u5916\u7684\u5185\u6838\u6a21\u5757\u63d0\u4f9b\u652f\u6301\uff0c\u4ee5-m \u6a21\u5757\u540d\u79f0\u7684\u5f62\u5f0f\u8c03\u7528\u76f8\u5e94\u7684\u6a21\u5757\uff0c\u7136\u540e\u8bbe\u7f6e\u5339\u914d\u6761\u4ef6\u3002<\/p>\n\n\n\n

                          \u5e38\u89c1\u7684\u663e\u793a\u5339\u914d\uff1a\u591a\u7aef\u53e3\u5339\u914d\u3001IP \u8303\u56f4\u5339\u914d\u3001MAC \u5730\u5740\u5339\u914d\u3001\u72b6\u6001\u5339\u914d\uff1b<\/p>\n\n\n\n

                          \u591a\u7aef\u53e3\u5339\u914d<\/strong><\/strong><\/p>\n\n\n\n

                          \u7f16\u5199iptables\u89c4\u5219\u65f6\u4f7f\u7528-m multiport –dports \u7aef\u53e3\u5217\u8868\u3001-m multiport –sports \u7aef\u53e3\u5217\u8868\u7684\u5f62\u5f0f\u6307\u5b9a\uff1b<\/p>\n\n\n\n

                          \u7528\u6765\u68c0\u67e5\u6570\u636e\u5305\u7684\u6e90\u7aef\u53e3\u3001\u76ee\u6807\u7aef\u53e3\u3001\u591a\u4e2a\u7aef\u53e3\u4e4b\u95f4\u4ee5\u9017\u53f7\u8fdb\u884c\u5206\u9694\uff1b<\/p>\n\n\n\n

                          \u6bd4\u65b9\u8bf4\uff1a\u82e5\u8981\u5141\u8bb8\u672c\u673a\u5f00\u653e\u7aef\u53e3\uff1a80\u3001443\u3001110 \u7b49\u7b49\uff0c\u63d0\u4f9b\u76f8\u5173\u670d\u52a1\uff1b<\/p>\n\n\n\n

                          # iptables -A INPUT -p tcp -m multiport –dport 80,443,110 -j ACCEPT<\/p>\n\n\n\n

                          IP <\/strong>\u8303\u56f4\u5339\u914d<\/strong><\/strong><\/p>\n\n\n\n

                          \u7f16\u5199iptables\u89c4\u5219\u65f6\u4f7f\u7528-m iprange –src-range IP \u8303\u56f4\u3001-m iprange –dst-range IP \u8303\u56f4\u7684\u5f62\u5f0f\u6307\u5b9a\uff1b<\/p>\n\n\n\n

                          \u7528\u6765\u68c0\u67e5\u6570\u636e\u5305\u7684\u6e90\u5730\u5740\u3001\u76ee\u6807\u5730\u5740\uff1b<\/p>\n\n\n\n

                          IP \u8303\u56f4\uff1a\u8d77\u59cb\u5730\u5740-\u7ed3\u675f\u5730\u5740\u7684\u5f62\u5f0f\u8868\u793a\uff1b<\/p>\n\n\n\n

                          \u6bd4\u65b9\u8bf4\uff1a\u8981\u7981\u6b62\u8f6c\u53d1\u6e90 IP \u5730\u5740\u4f4d\u4e8e 192.168.8.100 \u4e0e 192.168.8.123 \u4e4b\u95f4\u7684 TCP \u6570\u636e\u5305\uff1b<\/p>\n\n\n\n

                          # iptables -A FORWARD -p tcp -m iprange –src-range 192.168.8.100-192.168.8.123 -j ACCEPT<\/p>\n\n\n\n

                          MAC <\/strong>\u5730\u5740\u5339\u914d<\/strong><\/strong><\/p>\n\n\n\n

                          \u7f16\u5199iptables\u89c4\u5219\u65f6\u4f7f\u7528-m mac –mac-source MAC \u5730\u5740\u7684\u5f62\u5f0f\u6307\u5b9a\uff1b<\/p>\n\n\n\n

                          \u7528\u6765\u68c0\u67e5\u6570\u636e\u5305\u7684\u6e90 MAC \u5730\u5740\uff0c\u53ea\u9002\u7528\u4e8e\u5185\u90e8\u7f51\u7edc\uff1b<\/p>\n\n\n\n

                          \u6bd4\u65b9\u8bf4\uff1a\u8981\u6839\u636e MAC \u5730\u5740\u5c01\u9501\u4e3b\u673a\uff0c\u7981\u6b62\u5176\u8bbf\u95ee\u672c\u673a\u7684\u4efb\u4f55\u5e94\u7528\uff1b<\/p>\n\n\n\n

                          # iptables -A INPUT -m mac –mac-source MAC \u5730\u5740 xxx -j DROP<\/p>\n\n\n\n

                          \u72b6\u6001\u5339\u914d<\/strong><\/strong><\/p>\n\n\n\n

                          \u7f16\u5199iptables\u89c4\u5219\u65f6\u4f7f\u7528-m state –state \u8fde\u63a5\u72b6\u6001\u7684\u5f62\u5f0f\u6307\u5b9a\uff1b<\/p>\n\n\n\n

                          \u57fa\u4e8eiptables\u7684\u72b6\u6001\u8ddf\u8e2a\u673a\u5236\u7528\u6765\u68c0\u67e5\u6570\u636e\u5305\u7684\u8fde\u63a5\u72b6\u6001\uff1b<\/p>\n\n\n\n

                          \u5e38\u89c1\u7684\u8fde\u63a5\u72b6\u6001\u5305\u62ec\uff1anew\uff08\u4e0e\u4efb\u4f55\u8fde\u63a5\u65e0\u5173\uff09\u3001established\uff08\u54cd\u5e94\u8bf7\u6c42\u6216\u5df2\u5efa\u7acb\u8fde\u63a5\uff09\u3001related\uff08\u4e0e\u6709\u8fde\u63a5\u76f8\u5173\u6027\u7684\uff09\uff1b<\/p>\n\n\n\n

                          \u6bd4\u65b9\u8bf4\uff1a\u8981\u7981\u6b62\u8f6c\u53d1\u4e0e\u6b63\u5e38 TCP \u8fde\u63a5\u65e0\u5173\u7684\u975e –syn \u8bf7\u6c42\u6570\u636e\u5305\uff1b<\/p>\n\n\n\n

                          # iptables -A FORWARD -m state –state NEW -p tcp ! –syn -j DROP<\/p>\n\n\n\n

                          \u53ea\u5f00\u653e\u672c\u673a\u7684 WEB \u670d\u52a1\uff0c\u4f46\u5bf9\u53d1\u7ed9\u672c\u673a\u7684 TCP \u6570\u636e\u5305\u8fdb\u884c\u653e\u884c\uff0c\u5176\u4ed6\u5165\u6570\u636e\u5305\u4e22\u5f03\uff1b<\/p>\n\n\n\n

                          # iptables -I INPUT -p tcp -m multiport –dport 80 -j ACCEPT
                          # iptables -I INPUT -p tcp -m state –state ESTABLISHED -j ACCEPT
                          # iptables -P INPUT DROP<\/p>\n\n\n\n

                          \n\n\n\n

                          \uff08\u4e8c\uff09- SNAT \/ DNAT \u7b56\u7565\u53ca\u5e94\u7528<\/strong><\/p>\n\n\n\n

                          \"\"<\/figure><\/div>\n\n\n\n

                          SNAT <\/strong>\u7b56\u7565\u6982\u8ff0<\/strong><\/strong><\/p>\n\n\n\n

                          SNAT\u5168\u79f0\u4e3a\uff1aSource Network Address Translation \u6e90\u5730\u5740\u8f6c\u6362<\/p>\n\n\n\n

                          SNAT \u662f Linux \u9632\u706b\u5899\u7684\u4e00\u79cd\u5730\u5740\u8f6c\u6362\u64cd\u4f5c\uff0ciptables \u547d\u4ee4\u4e2d\u7684\u4e00\u79cd\u6570\u636e\u5305\u63a7\u5236\u7c7b\u578b\uff1b<\/p>\n\n\n\n

                          SNAT\u4f5c\u7528\uff1a\u6839\u636e\u6307\u5b9a\u6761\u4ef6\u4fee\u6539\u6570\u636e\u5305\u7684\u6e90 IP \u5730\u5740\u3002<\/p>\n\n\n\n

                          \u968f\u7740 IP \u5730\u5740\u8d44\u6e90\u9010\u6e10\u51cf\u5c11\uff0c\u4f7f\u4f01\u4e1a\u96be\u4ee5\u7533\u8bf7\u516c\u7f51 IP \u5730\u5740\uff0c\u6216\u53ea\u80fd\u627f\u8ba4\u4e00\u4e2a\u6216\u8005\u5c11\u6570\u51e0\u4e2a\u516c\u7f51 IP \u5730\u5740\u7684\u8d39\u7528\uff0c\u6240\u4ee5\u5728\u5927\u90e8\u5206\u4f01\u4e1a\u4e2d\u5c06\u9762\u4e34\u7740\u5c40\u57df\u7f51\u5185\u7684\u4e3b\u673a\u63a5\u5165 Internet \u7684\u9700\u6c42\u3002\u91c7\u7528\u5c0f\u578b\u7684\u4f01\u4e1a\u7f51\u7edc\uff0c\u901a\u8fc7\u5728\u7f51\u5173\u4e2d\u5e94\u7528 SNAT \u7b56\u7565\uff0c\u53ef\u89e3\u51b3\u5c40\u57df\u7f51\u5171\u4eab\u4e0a\u7f51\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n

                          Linux \u7f51\u5173\u670d\u52a1\u5668\u9700\u901a\u8fc7\u4e24\u5757\u7f51\u5361 eth1\u3001eth2\u5206\u522b\u8fde\u63a5 Internet \u548c \u5c40\u57df\u7f51\uff0c\u6765\u5206\u6790\u5c40\u57df\u7f51\u4e3b\u673a\u8bbf\u95ee Internet \u7684\u60c5\u51b5\u3002<\/p>\n\n\n\n

                          \"\"<\/figure><\/div>\n\n\n\n

                          \u5c40\u57df\u7f51\u5404\u4e3b\u673a\u6b63\u786e\u8bbe\u7f6e<\/strong> IP <\/strong>\u5730\u5740<\/strong> \/ <\/strong>\u5b50\u7f51\u63a9\u7801<\/strong> \/ <\/strong>\u9ed8\u8ba4\u7f51\u5173\u5730\u5740<\/strong><\/strong><\/p>\n\n\n\n

                          Eth1: 192.168.3.111\/24  Gw : 192.168.3.1
                          Eth2: 192.168.1.7\/24  (\u8fde\u63a5\u5185\u7f51\u7f51\u5361\u4e0d\u914d\u7f6e\u7f51\u5173)<\/p>\n\n\n\n

                          # ip a
                          1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
                              link\/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
                              inet 127.0.0.1\/8 scope host lo
                              inet6 ::1\/128 scope host 
                                 valid_lft forever preferred_lft forever
                          2: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
                              link\/ether 00:0c:29:f9:55:5b brd ff:ff:ff:ff:ff:ff
                              inet 192.168.1.7\/24 brd 192.168.1.255 scope global eth2
                              inet6 2409:8a00:30f8:4d70:20c:29ff:fef9:555b\/64 scope global dynamic 
                                 valid_lft 259010sec preferred_lft 172610sec
                              inet6 fe80::20c:29ff:fef9:555b\/64 scope link 
                                 valid_lft forever preferred_lft forever
                          3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
                              link\/ether 00:0c:29:f9:55:65 brd ff:ff:ff:ff:ff:ff
                              inet 192.168.3.111\/24 brd 192.168.3.255 scope global eth1
                              inet6 fe80::20c:29ff:fef9:5565\/64 scope link 
                                 valid_lft forever preferred_lft forever

                          # route -n
                          Kernel IP routing table
                          Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
                          192.168.3.0     0.0.0.0         255.255.255.0   U     1      0        0 eth1
                          192.168.1.0     0.0.0.0         255.255.255.0   U     1      0        0 eth2
                          0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 eth2<\/p>\n\n\n\n

                          \u5173\u95ed\u9632\u706b\u5899\u548c selinux<\/p>\n\n\n\n

                          # service iptables stop
                          iptables\uff1a\u5c06\u94fe\u8bbe\u7f6e\u4e3a\u653f\u7b56 ACCEPT\uff1afilter                    [\u786e\u5b9a]
                          iptables\uff1a\u6e05\u9664\u9632\u706b\u5899\u89c4\u5219\uff1a                                 [\u786e\u5b9a]
                          iptables\uff1a\u6b63\u5728\u5378\u8f7d\u6a21\u5757\uff1a                                   [\u786e\u5b9a]
                          # setenforce 0<\/p>\n\n\n\n

                          \u53ea\u5f00\u542f\u8def\u7531\u8f6c\u53d1\uff0c\u672a\u8bbe\u7f6e\u5730\u5740\u8f6c\u6362\u7684\u60c5\u51b5<\/strong><\/strong><\/p>\n\n\n\n

                          \u4f5c\u4e3a\u7f51\u5173\u7684 Linux \u670d\u52a1\u5668\u5fc5\u987b\u6253\u5f00\u8def\u7531\u8f6c\u53d1\uff0c\u624d\u80fd\u4e0e\u591a\u4e2a\u7f51\u7edc\u8fdb\u884c\u8fde\u901a\u3002<\/p>\n\n\n\n

                          \u672a\u4f7f\u7528\u5730\u5740\u8f6c\u6362\u7b56\u7565\u65f6\uff0c\u4ece\u5c40\u57df\u7f51 PC 192.168.1.123 \u8bbf\u95ee Internet \u7684\u6570\u636e\u5305\u7ecf\u8fc7\u7f51\u5173\u8f6c\u53d1\u540e\u5176\u6e90 IP \u4f4e\u81f3\u4fdd\u6301\u4e0d\u53d8\uff0c\u5f53 Internet \u4e2d\u7684\u4e3b\u673a\u6536\u5230\u8fd9\u6837\u7684\u8bf7\u6c42\u6570\u636e\u5305\u540e\uff0c\u54cd\u5e94\u6570\u636e\u5305\u5c06\u65e0\u6cd5\u6b63\u786e\u8fd4\u56de\uff0c\u4ece\u800c\u5bfc\u81f4\u8bbf\u95ee\u5931\u8d25\u3002(\u79c1\u7f51\u5730\u5740\u4e0d\u80fd\u5728 Internet \u4e2d\u6b63\u5e38\u8def\u7531)<\/p>\n\n\n\n

                          \"\"<\/figure><\/div>\n\n\n\n

                          \u5f00\u542f\u8def\u7531\u8f6c\u53d1\uff0c\u5e76\u8bbe\u7f6e<\/strong> SNAT <\/strong>\u8f6c\u6362\u7684\u60c5\u51b5<\/strong><\/strong><\/p>\n\n\n\n

                          \u5728\u7f51\u5173\u670d\u52a1\u5668\u4e2d\u6b63\u786e\u5e94\u7528 SNAT \u7b56\u7565\uff0c\u6570\u636e\u5305\u8f6c\u53d1\u60c5\u51b5\u5c31\u4e0d\u4e00\u6837\u4e86\u3002<\/p>\n\n\n\n

                          \u5c40\u57df\u7f51 PC \u8bbf\u95ee Internet \u7684\u6570\u636e\u5305\u5230\u8fbe\u7f51\u5173\u670d\u52a1\u5668\u65f6\uff0c\u5148\u8fdb\u884c\u8def\u7531\u9009\u62e9\uff0c\u82e5\u53d1\u73b0\u8be5\u6570\u636e\u5305\u9700\u8981\u4ece\u5916\u7f51\u63a5\u53e3 eth1 \u5411\u5916\u8f6c\u53d1\uff0c\u5219\u5c06\u5176\u6e90 IP \u5730\u5740 192.168.1.123 \u4fee\u6539\u4e3a\u7f51\u5173\u7684\u5916\u7f51\u63a5\u53e3\u5730\u5740 192.168.3.111\uff0c\u7136\u540e\u624d\u53d1\u9001\u7ed9\u76ee\u6807\u4e3b\u673a 192.168.3.112\u3002<\/p>\n\n\n\n

                          \u4ece\u7f51\u5173\u670d\u52a1\u5668\u7684\u516c\u7f51 IP \u5730\u5740\u63d0\u4ea4\u6570\u636e\u8bbf\u95ee\u8bf7\u6c42\uff0c\u76ee\u6807\u4e3b\u673a\u53ef\u6b63\u786e\u8fd4\u56de\u54cd\u5e94\u6570\u636e\u5305\uff0c\u6765\u5b9e\u73b0\u5c40\u57df\u7f51 PC \u5171\u4eab\u540c\u4e00\u4e2a\u516c\u7f51 IP \u5730\u5740\u63a5\u5165 Internet\u3002<\/p>\n\n\n\n

                          SNAT \u8f6c\u6362\u5730\u5740\u7684\u8fc7\u7a0b\u4e2d\uff0c\u7f51\u5173\u670d\u52a1\u5668\u4f1a\u6839\u636e\u4e4b\u524d\u5efa\u7acb\u7684 SNAT \u6620\u5c04\uff0c\u5c06\u54cd\u5e94\u6570\u636e\u5305\u6b63\u786e\u8fd4\u56de\u5c40\u57df\u7f51\u4e2d\u7684\u6e90\u4e3b\u673a\u3002\u53ea\u8981\u8fde\u63a5\u7684\u7b2c\u4e00\u4e2a\u5305\u88ab SNAT \u5904\u7406\u4e86\uff0c\u8fd9\u8fde\u63a5\u53ca\u5bf9\u5e94\u6570\u636e\u6d41\u7684\u5176\u4ed6\u5305\u4f1a\u81ea\u52a8\u7684\u88ab\u8fdb\u884c SNAT \u5904\u7406\u3002Internet \u4e2d\u7684\u670d\u52a1\u5668\u5176\u5b9e\u4e0d\u77e5\u9053\u5c40\u57df\u7f51 PC \u7684 IP \u5730\u5740\uff0c\u5176\u4e2d\u95f4\u7684\u8f6c\u6362\u5b8c\u5168\u7531\u7f51\u5173\u4e3b\u673a\u5b8c\u6210\uff0c\u53ef\u8d77\u5230\u5185\u7f51\u4fdd\u62a4\u7684\u4f5c\u7528\u3002<\/p>\n\n\n\n

                          \"\"<\/figure><\/div>\n\n\n\n

                          SNAT <\/strong>\u7b56\u7565\u5e94\u7528<\/strong><\/strong><\/p>\n\n\n\n

                          SNAT \u7b56\u7565\u5e94\u7528\uff1a\u662f\u4e3a\u5c40\u57df\u7f51\u5171\u4eab\u4e0a\u7f51\u63d0\u4f9b\u63a5\u5165\u7b56\u7565\uff0c\u5904\u7406\u6570\u636e\u5305\u7684\u5207\u5165\u65f6\u673a\u662f\u5728\u8def\u7531\u9009\u62e9\u540e\u8fdb\u884c\uff0c\u662f\u5c06\u5c40\u57df\u7f51\u5916\u53d1\u6570\u636e\u5305\u7684\u6e90 IP \u5730\u5740\u4fee\u6539\u4e3a\u7f51\u5173\u670d\u52a1\u5668\u7684\u5916\u7f51\u63a5\u53e3 IP \u5730\u5740\u3002<\/p>\n\n\n\n

                          SNAT \u7b56\u7565\u7528\u5728 nat \u8868\u7684 postrouting \u94fe\u3002<\/p>\n\n\n\n

                          \u7f16\u5199 SNAT \u7b56\u7565\u65f6\uff0c\u9700\u4f7f\u7528 iptables \u547d\u4ee4\u7ed3\u5408–to-source IP \u5730\u5740\u9009\u9879\u6765\u6307\u5b9a\u4fee\u6539\u540e\u7684\u6e90 IP \u5730\u5740\u3002<\/p>\n\n\n\n

                          \u5171\u4eab\u56fa\u5b9a<\/strong> IP <\/strong>\u5730\u5740\u4e0a\u7f51<\/strong><\/strong><\/p>\n\n\n\n

                          • Linux \u7f51\u5173\u670d\u52a1\u5668\u901a\u8fc7\u4e24\u5757\u7f51\u5361eth1\u3001eth2\u5206\u522b\u8fde\u63a5 Internet \u548c \u5c40\u57df\u7f51\u3002<\/li>
                          • \u6240\u6709\u5c40\u57df\u7f51 PC \u7684\u9ed8\u8ba4\u7f51\u5173\u8bbe\u7f6e\u4e3a\uff1a192.168.1.7\uff0c\u4e14\u5df2\u7ecf\u8bbe\u7f6e\u4e86 DNS \u670d\u52a1\u5668\u3002<\/li>
                          • \u8981\u6c42 192.168.3.0\/24 \u7f51\u6bb5\u7684 PC \u80fd\u591f\u901a\u8fc7\u5171\u4eab\u65b9\u5f0f\u6b63\u5e38\u8bbf\u95ee Internet\u3002<\/li><\/ul>\n\n\n\n

                            \u6253\u5f00\u7f51\u5173\u7684\u8def\u7531\u8f6c\u53d1<\/strong><\/strong><\/p>\n\n\n\n

                            IP \u8f6c\u53d1\u662f\u5b9e\u73b0\u8def\u7531\u529f\u80fd\u7684\u5173\u952e\uff0c\u5bf9\u5e94 \/proc \u6587\u4ef6\u7cfb\u7edf\u4e2d\u7684 ip_forward \u8bbe\u7f6e\u3002<\/p>\n\n\n\n

                            \u5f53\u503c\u4e3a 1 \u65f6\u8868\u793a\u5f00\u542f\uff0c\u4e3a 0 \u65f6\u8868\u793a\u5173\u95ed\u3002<\/p>\n\n\n\n

                            \u4f7f\u7528 Linux \u4e3b\u673a\u4f5c\u4e3a\u7f51\u5173\u8bbe\u5907\uff0c\u53ef\u4fee\u6539sysctl.conf \u914d\u7f6e\u6587\u4ef6\uff0c\u9700\u6c38\u4e45\u5f00\u542f\u8def\u7531\u8f6c\u53d1\u529f\u80fd\u3002<\/p>\n\n\n\n

                            # vi \/etc\/sysctl.conf 
                            7 net.ipv4.ip_forward = 1                   # \u5c06\u7b2c 7 \u884c\u7684\u914d\u7f6e\u7531\u539f\u6765\u7684 0 \u6539\u4e3a 1
                            # sysctl -p                                 # \u8bfb\u53d6\u4fee\u6539\u540e\u7684\u914d\u7f6e<\/p>\n\n\n\n

                            \u6d4b\u8bd5\u8fc7\u7a0b\u4e2d\uff0c\u53ef\u4e34\u65f6\u5f00\u542f\u8def\u7531\u8f6c\u53d1\u3002<\/p>\n\n\n\n

                            # echo 1 > \/proc\/sys\/net\/ipv4\/ip_forward 
                            # sysctl -w net.ipv4.ip_forward=1
                            net.ipv4.ip_forward = 1<\/p>\n\n\n\n

                            \u6b63\u786e\u8bbe\u7f6e<\/strong> SNAT <\/strong>\u7b56\u7565<\/strong><\/strong><\/p>\n\n\n\n

                            \u9488\u5bf9\u5c40\u57df\u7f51 PC \u8bbf\u95ee Internet \u7684\u6570\u636e\u5305\u91c7\u7528 SNAT \u7b56\u7565\uff0c\u5e76\u5c06\u6e90\u5730\u5740\u6539\u4e3a\u7f51\u5173\u7684\u516c\u7f51 IP \u5730\u5740\uff0c\u8bbe\u7f6e\u9632\u706b\u5899\u89c4\u5219\uff0c\u4fdd\u6301 SNAT \u7b56\u7565\u957f\u671f\u6709\u6548\uff0c\u5e76\u5c06\u76f8\u5173\u547d\u4ee4\u5199\u5165\u5230rc.local\u914d\u7f6e\u6587\u4ef6\uff0c\u65b9\u4fbf\u5f00\u673a\u540e\u81ea\u52a8\u8bbe\u7f6e\u3002<\/p>\n\n\n\n

                            # iptables -t nat -A POSTROUTING -s 192.168.1.0\/24 -o eth1 -j SNAT–to-source 192.168.3.111<\/p>\n\n\n\n

                            \u6d4b\u8bd5<\/strong> SNAT <\/strong>\u7b56\u7565\u5171\u4eab\u63a5\u5165\u7ed3\u679c<\/strong><\/strong><\/p>\n\n\n\n

                            \u4f7f\u7528\u5c40\u57df\u7f51\u4e2d\u7684 PC \u4fbf\u53ef\u4ee5\u6b63\u5e38\u8bbf\u95ee Internet \u4e2d\u7684\u7f51\u7ad9\u4e86\u3002<\/p>\n\n\n\n

                            \u88ab\u8bbf\u95ee\u7684\u7f51\u7ad9\u670d\u52a1\u5668\uff0c\u4f1a\u8ba4\u4e3a\u662f\u7f51\u5173\u4e3b\u673a 192.168.3.111 \u5728\u8bbf\u95ee\u83b7\u53d6 web \u65e5\u5fd7\uff0c\u800c\u5e76\u4e0d\u77e5\u9053\u662f\u5426\u662f\u5b9e\u9645\u4f01\u4e1a\u5185\u7f51\u7684 PC \u5730\u5740 192.168.3.123 \u5728\u8bbf\u95ee\u3002<\/p>\n\n\n\n

                            \u542f\u52a8\u4e00\u53f0 Windows \u8bbe\u5907\uff0c\u6839\u636e\u5b9e\u9645\u60c5\u51b5\u914d\u7f6e IP \u5730\u5740\uff0c\u5e76\u6d4b\u8bd5\u8fde\u901a\u6027\uff1b<\/p>\n\n\n\n

                            \"\"<\/figure><\/div>\n\n\n\n

                            \u5728 Windows \u64cd\u4f5c\u7cfb\u7edf\u4e0a\u5b89\u88c5 IIS \u670d\u52a1\uff0c\u9009\u62e9 Internet \u4fe1\u606f\u670d\u52a1\u9009\u9879\u5373\u53ef\uff1b<\/p>\n\n\n\n

                            \"\"<\/figure><\/div>\n\n\n\n

                            \u5b89\u88c5\u5b8c\u6bd5\u4e4b\u540e\uff0c\u6253\u5f00\u6d4f\u89c8\u5668\u8f93\u5165\u672c\u673a\u7684 IP \u5730\u5740\u5373\u53ef\u8bbf\u95ee\uff1b<\/p>\n\n\n\n

                            \"\"<\/figure><\/div>\n\n\n\n

                            \u5171\u4eab\u52a8\u6001<\/strong> IP <\/strong>\u5730\u5740\u4e0a\u7f51<\/strong><\/strong><\/p>\n\n\n\n

                            iptables \u63d0\u4f9b\u4e86\u4e00\u4e2a\u540d\u4e3a masquerade \u7684\u6570\u636e\u5305\u63a7\u5236\u7c7b\u578b\uff0c\u53ef\u7528\u6765\u4fee\u6539\u6570\u636e\u5305\u6e90 IP \u5730\u5740\uff0c\u80fd\u591f\u81ea\u52a8\u83b7\u53d6\u5916\u7f51\u63a5\u53e3\u7684 IP \u5730\u5740\uff0c\u4e0d\u9700\u8981\u4f7f\u7528–to-source\u6307\u5b9a\u56fa\u5b9a\u7684 IP \u5730\u5740\u3002<\/p>\n\n\n\n

                            \u82e5\u8981\u4f7f\u7528 MASQUERADE \u4f2a\u88c5\u7b56\u7565\uff0c\u53ea\u9700\u53bb\u6389 SNAT \u7b56\u7565\u4e2d\u7684 –to-source IP \u5730\u5740\uff0c\u7136\u540e\u4f7f\u7528 -j MASQUERADE \u6307\u5b9a\u6570\u636e\u5305\u63a7\u5236\u7c7b\u578b\u3002<\/p>\n\n\n\n

                            ADSL \u5bbd\u5e26\u94fe\u63a5\uff0c\u901a\u5e38\u8fde\u63a5\u540d\u79f0\u4e3a\uff1appp0\u3001ppp1\u7b49\u7b49\uff1b<\/p>\n\n\n\n

                            # iptables -t nat -A POSTROUTING -s 192.168.1.0\/24 -o ppp0 -j MASQUERADE<\/p>\n\n\n\n

                            \u5982\u679c\u7f51\u5173\u4f7f\u7528\u56fa\u5b9a\u7684\u516c\u7f51 IP \u5730\u5740\uff0c\u6700\u597d\u9009\u62e9 SNAT \u7b56\u7565\u800c\u4e0d\u662f masquerade \u7b56\u7565\uff0c\u4ee5\u51cf\u5c11\u4e0d\u5fc5\u8981\u7684\u7cfb\u7edf\u5f00\u9500\u3002 <\/p>\n\n\n\n

                            DNAT <\/strong>\u7b56\u7565\u53ca\u5e94\u7528<\/strong><\/p>\n\n\n\n

                            DNAT \u5168\u79f0\u4e3a\uff1aDestination Network Address Translation \uff08\u76ee\u6807\u5730\u5740\u8f6c\u6362\uff09<\/p>\n\n\n\n

                            DNAT \u662fLinux \u9632\u706b\u5899\u7684\u53e6\u4e00\u79cd\u5730\u5740\u8f6c\u6362\u64cd\u4f5c\uff0c\u662fiptables\u547d\u4ee4\u4e2d\u7684\u4e00\u79cd\u6570\u636e\u5305\u63a7\u5236\u7c7b\u578b\uff1b<\/p>\n\n\n\n

                            \u4f5c\u7528\uff1a\u6839\u636e\u6307\u5b9a\u6761\u4ef6\u4fee\u6539\u6570\u636e\u5305\u7684\u76ee\u6807<\/strong> IP <\/strong>\u5730\u5740\u548c\u76ee\u6807\u7aef\u53e3\u3002<\/strong><\/strong><\/p>\n\n\n\n

                            DNAT <\/strong>\u7b56\u7565\u6982\u8ff0<\/strong><\/strong><\/p>\n\n\n\n

                            DNAT\uff1a\u7528\u6765\u4fee\u6539\u76ee\u6807 IP \u5730\u5740\u548c\u76ee\u6807\u7aef\u53e3\uff0c\u7528\u5728 nat \u8868\u7684 PREROUTING \u94fe\u548c OUTPUT \u94fe\u4e2d\u3002<\/p>\n\n\n\n

                            \u4e0e SNAT \u76f8\u4f3c\uff0cSNAT \u7528\u6765\u4fee\u6539\u6e90 IP \u5730\u5740\uff0c\u7528\u5728 nat \u8868\u7684 POSTROUTING \u94fe\u3002<\/p>\n\n\n\n

                            \"\"<\/figure><\/div>\n\n\n\n

                            \u5728 Internet \u73af\u5883\u4e2d\uff0c\u6240\u6ce8\u518c\u7684\u7f51\u7ad9\u57df\u540d\u5fc5\u987b\u5bf9\u5e94\u5408\u6cd5\u7684\u516c\u7f51 IP \u5730\u5740\uff0cInternet PC \u5c06\u65e0\u6cd5\u8bbf\u95ee\u516c\u53f8\u5185\u7f51\u7684\u670d\u52a1\u5668\uff0c\u9664\u975e\u5728\u7f51\u5173\u670d\u52a1\u5668\u4e2d\u6b63\u786e\u8bbe\u7f6e DNAT \u7b56\u7565\u3002<\/p>\n\n\n\n

                            Internet PC \u63d0\u4ea4\u7684 HTTP \u8bf7\u6c42\u5230\u4f01\u4e1a\u7684\u7f51\u5173\u670d\u52a1\u5668\u65f6\uff0c\u7f51\u5173\u670d\u52a1\u5668\u9996\u5148\u5224\u65ad\u6570\u636e\u5305\u7684\u76ee\u6807\u5730\u5740\u548c\u76ee\u6807\u7aef\u53e3\uff0c\u53d1\u73b0\u6570\u636e\u5305\u9700\u8981\u8bbf\u95ee\u672c\u673a\u7684 80 \u7aef\u53e3\uff0c\u5219\u5c06\u5176\u76ee\u6807 IP \u5730\u5740\u4fee\u6539\u4e3a\u5185\u7f51\u4e2d\u7684\u7f51\u7ad9\u670d\u52a1\u5668 IP \u5730\u5740\uff0c\u7136\u540e\u53d1\u9001\u7ed9\u5185\u90e8\u7684\u7f51\u7ad9\u670d\u52a1\u5668\u3002<\/p>\n\n\n\n

                            \u7f51\u5173\u670d\u52a1\u5668\u4f1a\u6839\u636e\u4e4b\u524d\u5efa\u7acb\u7684 DNAT \u6620\u5c04\uff0c\u4fee\u6539\u8fd4\u56de\u7684 HTTP \u5e94\u7b54\u6570\u636e\u5305\u7684\u6e90 IP \u5730\u5740\uff0c\u518d\u8fd4\u56de\u7ed9 Internet PC \u3002<\/p>\n\n\n\n

                            Internet PC \u5176\u5b9e\u4e0d\u77e5\u9053\u4f01\u4e1a\u7f51\u7ad9\u670d\u52a1\u5668\u7684\u5c40\u57df\u7f51\u5730\u5740\uff0c\u4e2d\u95f4\u8f6c\u6362\u662f\u7531\u7f51\u5173\u4e3b\u673a\u5b8c\u6210\uff0c\u901a\u8fc7\u8bbe\u7f6e\u7684 DNAT \u7b56\u7565\uff0c\u4f01\u4e1a\u5185\u90e8\u7684\u670d\u52a1\u5668\u5c31\u53ef\u4ee5\u9762\u5411 Internet \u63d0\u4f9b\u670d\u52a1\u3002<\/p>\n\n\n\n

                            \"\"<\/figure><\/div>\n\n\n\n

                            DNAT <\/strong>\u7b56\u7565\u5e94\u7528<\/strong><\/strong><\/p>\n\n\n\n

                            DNAT \u5e94\u7528\uff1a\u662f\u5728 Internet \u4e2d\u53d1\u5e03\u4f01\u4e1a\u5185\u90e8\u7684\u670d\u52a1\u5668\uff0c\u5904\u7406\u6570\u636e\u5305\u7684\u5207\u5165\u65f6\u673a\u662f\u5728\u8def\u7531\u9009\u62e9\u4e4b\u524d\u8fdb\u884c\u3002\u5c06\u8bbf\u95ee\u7f51\u5173\u5916\u7f51\u63a5\u53e3 IP \u5730\u5740\u7684\u6570\u636e\u5305\u7684\u76ee\u6807\u5730\u5740\u4fee\u6539\u4e3a\u5b9e\u9645\u63d0\u4f9b\u670d\u52a1\u7684\u5185\u90e8\u670d\u52a1\u5668\u7684 IP \u5730\u5740\u3002<\/p>\n\n\n\n

                            \u4f7f\u7528 iptables \u547d\u4ee4\u8bbe\u7f6e DNAT \u7b56\u7565\u65f6\uff0c\u9700\u8981\u7ed3\u5408–to-destination IP \u5730\u5740\u9009\u9879\u6765\u6307\u5b9a\u5185\u90e8\u670d\u52a1\u5668\u7684 IP \u5730\u5740\u3002<\/p>\n\n\n\n

                            \u53d1\u5e03\u4f01\u4e1a\u5185\u90e8\u7684<\/strong> web <\/strong>\u670d\u52a1\u5668<\/strong><\/strong><\/p>\n\n\n\n

                            • \u516c\u53f8\u9700\u6ce8\u518c\u7f51\u7ad9\u57df\u540d\uff0cIP \u5730\u5740\u4e3a 192.168.3.111<\/li>
                            • \u516c\u53f8\u7684\u7f51\u7ad9\u670d\u52a1\u5668\u4f4d\u4e8e\u5c40\u57df\u7f51\u5185\uff0cIP \u5730\u5740\u4e3a 192.168.3.112<\/li>
                            • \u8981\u6c42\u80fd\u591f\u4ece Internet \u4e2d\u901a\u8fc7\u8bbf\u95ee\u7f51\u7ad9\u57df\u540d\u6765\u67e5\u770b\u516c\u53f8\u7684\u7f51\u7ad9\u5185\u5bb9<\/li><\/ul>\n\n\n\n

                              \u6253\u5f00\u7f51\u5173\u7684\u8def\u7531\u8f6c\u53d1<\/strong><\/strong><\/p>\n\n\n\n

                              # vi \/etc\/sysctl.conf 
                              7 net.ipv4.ip_forward = 1                   # \u5c06\u7b2c 7 \u884c\u7684\u914d\u7f6e\u7531\u539f\u6765\u7684 0 \u6539\u4e3a 1
                              # sysctl -p                                 # \u8bfb\u53d6\u4fee\u6539\u540e\u7684\u914d\u7f6e<\/p>\n\n\n\n

                              \u6b63\u786e\u8bbe\u7f6e<\/strong> DNAT <\/strong>\u7b56\u7565<\/strong><\/strong><\/p>\n\n\n\n

                              \u9488\u5bf9 Internet \u4e2d\u7684\u4efb\u610f\u4e3b\u673a\u8bbf\u95ee\u7f51\u5173 80 \u7aef\u53e3\u7684\u6570\u636e\u5305\uff0c\u5c06\u76ee\u6807\u5730\u5740\u4fee\u6539\u4e3a\u4f4d\u4e8e\u5185\u7f51\u7684\u7f51\u7ad9\u670d\u52a1\u5668 IP \u5730\u5740\u3002<\/p>\n\n\n\n

                              # iptables -t nat -A PREROUTING -i eth2 -d 192.168.1.7 -p tcp –dport 80 -j DNAT –to-destination 192.168.3.112
                              # iptables -t nat -L -n -v
                              Chain PREROUTING (policy ACCEPT 0 packets, 0 bytes)
                               pkts bytes target     prot opt in     out     source               destination         
                                  0     0 DNAT       tcp  —  eth2   *       0.0.0.0\/0            192.168.1.7         tcp dpt:80 to:192.168.3.112 

                              Chain POSTROUTING (policy ACCEPT 1 packets, 136 bytes)
                               pkts bytes target     prot opt in     out     source               destination         

                              Chain OUTPUT (policy ACCEPT 1 packets, 136 bytes)
                               pkts bytes target     prot opt in     out     source               destination <\/p>\n\n\n\n

                              \u6d4b\u8bd5<\/strong> DNAT <\/strong>\u53d1\u5e03\u7ed3\u679c<\/strong><\/strong><\/p>\n\n\n\n

                              \u5728\u7f51\u7ad9\u670d\u52a1\u5668 192.168.3.112 \u4e2d\u6b63\u786e\u8bbe\u7f6e\uff0c\u542f\u52a8 web \u670d\u52a1\uff0c\u6d4b\u8bd5\u7f51\u9875\uff0c\u53ef\u81ea\u5b9a\u4e49\u4fee\u6539\u9996\u9875\u6587\u4ef6\uff0c\u7136\u540e\u901a\u8fc7 Internet \u4e2d\u7684\u5ba2\u6237\u673a\u8bbf\u95ee\u7f51\u7ad9\uff0c\u4e0d\u505a DNS \u89e3\u6790\uff0c\u4e5f\u53ef\u76f4\u63a5\u8bbf\u95ee\u3002<\/p>\n\n\n\n

                              \u53d1\u5e03\u4f01\u4e1a\u5185\u90e8\u7684<\/strong> OpenSSH <\/strong>\u670d\u52a1\u5668<\/strong><\/strong><\/p>\n\n\n\n

                              DNAT \u7b56\u7565\uff1a\u7528\u6765\u4fee\u6539\u6570\u636e\u5305\u7684\u76ee\u6807 IP \u5730\u5740\uff0c\u4f46\u5728\u9700\u8981\u65f6\u4e5f\u53ef\u4fee\u6539\u76ee\u6807\u7aef\u53e3\u53f7\u3002<\/p>\n\n\n\n

                              \u914d\u7f6e<\/strong> OpenSSH <\/strong>\u670d\u52a1<\/strong><\/strong><\/p>\n\n\n\n

                              \u5728\u7f51\u5173\uff0c\u7f51\u7ad9\u670d\u52a1\u5668\u4e2d\u5f00\u542f OpenSSH \u670d\u52a1\uff0c\u5206\u522b\u4f7f\u7528 2345\u300122 \u7aef\u53e3\u3002<\/p>\n\n\n\n

                              \u7f51\u5173\u7684 sshd \u670d\u52a1\u56e0\u76f4\u63a5\u9762\u5411 Internet\uff0c\u56e0\u6b64\u4e0d\u4f7f\u7528\u9ed8\u8ba4\u7aef\u53e3\u3002<\/p>\n\n\n\n

                              \u6253\u5f00\u7f51\u5173\u7684\u8def\u7531\u8f6c\u53d1<\/strong><\/strong><\/p>\n\n\n\n

                              # vi \/etc\/sysctl.conf 
                              7 net.ipv4.ip_forward = 1                   # \u5c06\u7b2c 7 \u884c\u7684\u914d\u7f6e\u7531\u539f\u6765\u7684 0 \u6539\u4e3a 1
                              # sysctl -p                                 # \u8bfb\u53d6\u4fee\u6539\u540e\u7684\u914d\u7f6e<\/p>\n\n\n\n

                              \u6b63\u786e\u8bbe\u7f6e<\/strong> DNAT <\/strong>\u7b56\u7565<\/strong><\/strong><\/p>\n\n\n\n

                              \u7f51\u5173\u672c\u673a\u7684 sshd \u670d\u52a1\u76f4\u63a5\u9762\u5411 Internet\uff0c\u4e0d\u9700\u8981\u5730\u5740\u8f6c\u6362\uff0c\u4f46\u7f51\u7ad9\u670d\u52a1\u5668\u4f4d\u4e8e\u5185\u7f51\uff0c\u9700\u901a\u8fc7 DNAT \u7b56\u7565\u8fdb\u884c\u53d1\u5e03\u3002<\/p>\n\n\n\n

                              \u7f51\u5173\u8bbe\u7f6e\u9632\u706b\u5899\u89c4\u5219\uff0c\u4fee\u6539\u8bbf\u95ee\u5916\u7f51\u7684 IP \u5730\u5740 2346 \u7aef\u53e3\u7684\u6570\u636e\u5305\uff0c\u53ca\u4fee\u6539\u76ee\u6807\u5730\u5740\u548c\u7aef\u53e3\uff0c\u4fbf\u4e8e\u8f6c\u53d1\u7ed9\u7f51\u7ad9\u670d\u52a1\u5668\u3002<\/p>\n\n\n\n

                              # iptables -t nat -A PREROUTING -i eth2 -d 192.168.1.7 -p tcp –dport 2346 -j DNAT –to-destination 192.168.3.112:22<\/p>\n\n\n\n

                              \u6d4b\u8bd5<\/strong> DNAT <\/strong>\u53d1\u5e03\u7ed3\u679c<\/strong><\/strong><\/p>\n\n\n\n

                              \u4f7f\u7528ssh -p 2345 \/ 2346 \u7528\u6237\u540d@eth2 IP \u5730\u5740\u5373\u53ef\u767b\u5f55\u7f51\u5173\u670d\u52a1\u5668<\/p>\n\n\n\n

                              \uff08\u4e09\uff09- \u89c4\u5219\u7684\u5bfc\u51fa \/ \u5bfc\u5165\u3001\u4f7f\u7528\u9632\u706b\u5899\u811a\u672c\u7a0b\u5e8f<\/strong><\/p>\n\n\n\n

                              \"\"<\/figure>\n\n\n\n

                              1<\/strong>\u3001\u9632\u706b\u5899\u89c4\u5219\u7684\u5907\u4efd\u53ca\u8fd8\u539f<\/strong><\/strong><\/p>\n\n\n\n

                              \u9632\u706b\u5899\u89c4\u5219\u7684\u6279\u91cf\u5907\u4efd\u3001\u8fd8\u539f\u4e24\u4e2a\u547d\u4ee4\uff0c\u5206\u522b\u662f\uff1aiptables-save\u548ciptables-restore\uff0c\u7528\u6765\u4fdd\u5b58\u548c\u6062\u590d\u3002<\/p>\n\n\n\n

                              1.1 iptables-save <\/strong>\u547d\u4ee4<\/strong><\/strong><\/p>\n\n\n\n

                              iptables-save \u547d\u4ee4\uff1a\u7528\u6765\u6279\u91cf\u5bfc\u51fa Linux \u9632\u706b\u5899\u89c4\u5219\u3002<\/p>\n\n\n\n

                              \u76f4\u63a5\u6267\u884ciptables-save \u547d\u4ee4\u65f6\uff0c\u5c06\u663e\u793a\u51fa\u5f53\u524d\u542f\u7528\u7684\u6240\u6709\u89c4\u5219\u3002<\/p>\n\n\n\n

                              # iptables-save
                              # Generated by iptables-save v1.4.7 on Mon Oct  7 20:09:30 2019
                              *nat
                              :PREROUTING ACCEPT [134:12724]
                              :POSTROUTING ACCEPT [10:645]
                              :OUTPUT ACCEPT [10:645]
                              -A PREROUTING -d 192.168.1.4\/32 -i eth2 -p tcp -m tcp –dport 80 -j DNAT –to-destination 192.168.3.112 
                              COMMIT
                              # Completed on Mon Oct  7 20:09:30 2019
                              # Generated by iptables-save v1.4.7 on Mon Oct  7 20:09:30 2019
                              *filter
                              :INPUT ACCEPT [0:0]
                              :FORWARD ACCEPT [0:0]
                              :OUTPUT ACCEPT [257:22057]
                              -A INPUT -m state –state RELATED,ESTABLISHED -j ACCEPT 
                              -A INPUT -p icmp -j ACCEPT 
                              -A INPUT -i lo -j ACCEPT 
                              -A INPUT -p tcp -m state –state NEW -m tcp –dport 22 -j ACCEPT 
                              -A INPUT -j REJECT –reject-with icmp-host-prohibited 
                              -A FORWARD -j REJECT –reject-with icmp-host-prohibited 
                              COMMIT
                              # Completed on Mon Oct  7 20:09:30 2019<\/p>\n\n\n\n

                              \u4e0a\u8ff0\u8f93\u51fa\u7684\u5404\u9879\u542b\u4e49\uff1a<\/strong><\/strong><\/p>\n\n\n\n

                              • # \u53f7\u5f00\u5934\u7684\u5185\u5bb9\u8868\u793a\u6ce8\u91ca\uff1b<\/li>
                              • *\u8868\u540d\uff1a\u8868\u793a\u6240\u5728\u7684\u8868\uff1b\u4f8b\u5982\uff1a*nat<\/li>
                              • :\u94fe\u540d \u9ed8\u8ba4\u7b56\u7565\uff1a\u8868\u793a\u76f8\u5e94\u7684\u94fe\u53ca\u9ed8\u8ba4\u7b56\u7565\uff0c\u5177\u4f53\u89c4\u5219\u90e8\u5206\u7701\u7565\u4e86iptables\u547d\u4ee4\u540d\uff1b<\/li>
                              • COMMIT\uff1a\u8868\u793a\u63d0\u4ea4\u524d\u9762\u7684\u89c4\u5219\u8bbe\u7f6e\uff1b<\/li><\/ul>\n\n\n\n

                                iptables-save \u547d\u4ee4\uff1a\u53ea\u662f\u628a\u89c4\u5219\u5185\u5bb9\u8f93\u51fa\u5230\u5c4f\u5e55\u4e0a\uff0c\u5f53\u9700\u8981\u4fdd\u5b58\u4e3a\u56fa\u5b9a\u7684\u6587\u4ef6\u65f6\uff0c\u7ed3\u5408\u91cd\u5b9a\u5411\u8f93\u51fa\u7684\u64cd\u4f5c\u6765\u5b8c\u6210\u5907\u4efd\u3002<\/p>\n\n\n\n

                                \u5c06\u5f53\u524d\u5df2\u8bbe\u7f6e\u7684\u6240\u6709\u9632\u706b\u5899\u89c4\u5219\u5907\u4efd\u4e3aiptables_beifen.txt\u6587\u4ef6\uff0c\u53ef\u6267\u884c\u5982\u4e0b\u547d\u4ee4\u5373\u53ef\uff0c\u5907\u4efd\u5b8c\u6210\u540e\uff0c\u53ef\u67e5\u770b\u6240\u5907\u4efd\u5230\u7684\u8def\u5f84\u4e0b\u662f\u5426\u5b58\u5728\u8be5\u6587\u4ef6\uff1b<\/p>\n\n\n\n

                                # iptables-save > \/root\/iptables_beifen.txt
                                # ll | grep iptables_beifen.txt 
                                -rw-r–r–. 1 root root   782 10\u6708  7 20:26 iptables_beifen.txt<\/p>\n\n\n\n

                                1.2 iptables-restore <\/strong>\u547d\u4ee4<\/strong><\/strong><\/p>\n\n\n\n

                                iptables-restore \u547d\u4ee4\uff1a\u7528\u6765\u6279\u91cf\u5bfc\u5165 Linux \u9632\u706b\u5899\u89c4\u5219\uff0c\u4e0eiptables-save \u547d\u4ee4\u76f8\u7ed3\u5408\u91cd\u5b9a\u5411\u8f93\u5165\u6765\u6307\u5b9a\u5907\u4efd\u6587\u4ef6\u7684\u4f4d\u7f6e\u3002<\/p>\n\n\n\n

                                # iptables-restore < \/root\/iptables_beifen.txt<\/p>\n\n\n\n

                                2<\/strong>\u3001\u4f7f\u7528<\/strong> iptables <\/strong>\u670d\u52a1<\/strong><\/strong><\/p>\n\n\n\n

                                iptables \u670d\u52a1\u4f7f\u7528\u7684\u89c4\u5219\u6587\u4ef6\u4f4d\u4e8e \/etc\/sysconfig\/iptables \u6587\u4ef6\u4e2d\u3002<\/p>\n\n\n\n

                                \u901a\u8fc7 iptables \u7cfb\u7edf\u670d\u52a1\uff0c\u53ef\u5feb\u901f\u542f\u7528\u3001\u6e05\u7a7a\u9632\u706b\u5899\u89c4\u5219\u3002<\/p>\n\n\n\n

                                2.1 <\/strong>\u81ea\u52a8\u542f\u7528\u9632\u706b\u5899\u89c4\u5219<\/strong><\/strong><\/p>\n\n\n\n

                                \u4f7f\u7528iptables-save\u5907\u4efd\u4e3a\u9ed8\u8ba4\u7684\u89c4\u5219\u914d\u7f6e\u6587\u4ef6 \/etc\/sysconfig\/iptables \u7136\u540e\u53ef\u4ee5\u901a\u8fc7 iptables \u670d\u52a1\u6765\u8c03\u7528\u3002<\/p>\n\n\n\n

                                \u5c06\u4fdd\u5b58\u5f53\u524d\u7684\u9632\u706b\u5899\u89c4\u5219\uff0c\u5e76\u8bbe\u7f6e\u5728\u6bcf\u6b21\u5f00\u673a\u540e\u6839\u636e\u5df2\u4fdd\u5b58\u7684\u89c4\u5219\u5185\u5bb9\u81ea\u52a8\u8fdb\u884c\u91cd\u5efa\u3002<\/p>\n\n\n\n

                                # iptables-save > \/etc\/sysconfig\/iptables
                                # chkconfig –level 2345 iptables on
                                # chkconfig –list iptables
                                iptables           0:\u5173\u95ed    1:\u5173\u95ed    2:\u542f\u7528    3:\u542f\u7528    4:\u542f\u7528    5:\u542f\u7528    6:\u5173\u95ed<\/p>\n\n\n\n

                                \u542f\u7528 \/etc\/sysconfig\/iptables \u6587\u4ef6\u4e2d\u7684\u89c4\u5219\u8bbe\u7f6e\u65f6\uff0c\u53ea\u9700\u8981\u542f\u52a8 iptables \u670d\u52a1\u5373\u53ef\u3002<\/p>\n\n\n\n

                                # service iptables start<\/p>\n\n\n\n

                                2.2 <\/strong>\u6e05\u7a7a\u6240\u6709\u9632\u706b\u5899\u89c4\u5219<\/strong><\/strong><\/p>\n\n\n\n

                                \u8c03\u8bd5\u5404\u79cd\u9632\u706b\u5899\u89c4\u5219\u7684\u8fc7\u7a0b\u4e2d\uff0c\u4e3a\u4e86\u6392\u9664\u5176\u4ed6\u89c4\u5219\u7684\u5e72\u6270\uff0c\u9700\u6e05\u7a7a\u67d0\u4e9b\u8868\u7684\u89c4\u5219\u3002<\/p>\n\n\n\n

                                \u9700\u8981\u4f9d\u6b21\u6e05\u7a7a\u6240\u6709\u8868\u7684\u89c4\u5219\u65f6\uff0c\u505c\u7528 iptables \u670d\u52a1\u662f\u6700\u597d\u7684\u529e\u6cd5\u3002<\/p>\n\n\n\n

                                # service iptables stop
                                iptables\uff1a\u5c06\u94fe\u8bbe\u7f6e\u4e3a\u653f\u7b56 ACCEPT\uff1anat filter                [\u786e\u5b9a]
                                iptables\uff1a\u6e05\u9664\u9632\u706b\u5899\u89c4\u5219\uff1a                                 [\u786e\u5b9a]
                                iptables\uff1a\u6b63\u5728\u5378\u8f7d\u6a21\u5757\uff1a                                   [\u786e\u5b9a]
                                # service iptables status
                                iptables\uff1a\u672a\u8fd0\u884c\u9632\u706b\u5899\u3002<\/p>\n\n\n\n

                                3<\/strong>\u3001\u9632\u706b\u5899\u811a\u672c\u7684\u7ec4\u6210<\/strong><\/strong><\/p>\n\n\n\n

                                \u6709\u540c\u5b66\u53ef\u80fd\u4f1a\u6709\u7591\u95ee\uff0c\u9632\u706b\u5899\u8fd8\u6709\u811a\u672c\u5e94\u7528\uff1f\u5177\u4f53\u90fd\u6709\u54ea\u4e9b\u5185\u5bb9\u7ec4\u6210\u5462\uff1f\u7b49\u7b49\uff1b<\/p>\n\n\n\n

                                \u9632\u706b\u5899\u811a\u672c\u7684\u4f18\u52bf\uff1a\u4fbf\u4e8e\u4f7f\u7528 Shell \u53d8\u91cf\u3001\u7a0b\u5e8f\u63a7\u5236\u903b\u8f91\u3001\u4f5c\u4e3a\u72ec\u7acb\u7684\u6587\u4ef6\u5728\u9700\u8981\u91cd\u7528\u3001\u79fb\u690d\u4f7f\u7528\u65f6\u66f4\u65b9\u4fbf\uff1b<\/p>\n\n\n\n

                                3.1 <\/strong>\u5b9a\u4e49\u57fa\u672c\u53d8\u91cf<\/strong><\/strong><\/p>\n\n\n\n

                                \u9632\u706b\u5899\u7684\u7f51\u5361\u3001IP \u5730\u5740\u3001\u5c40\u57df\u7f51\u6bb5\u3001iptables \u547d\u4ee4\u7684\u8def\u5f84\u7b49\u5b9a\u4e49\u4e3a\u53d8\u91cf\uff0c\u4fbf\u4e8e\u5bf9\u811a\u672c\u7a0b\u5e8f\u7684\u7ef4\u62a4\u548c\u79fb\u690d\u4f7f\u7528\u3002<\/p>\n\n\n\n

                                \u89c4\u5219\u591a\u65f6\uff0c\u4e00\u65e6\u7f51\u7edc\u73af\u5883\u51fa\u73b0\u95ee\u9898\uff0c\u53ea\u9700\u5bf9\u53d8\u91cf\u503c\u8fdb\u884c\u4fee\u6539\u5c31\u53ef\u4ee5\u4f7f\u7528\u4e86\u3002<\/p>\n\n\n\n

                                # vi \/opt\/myiptables.sh
                                #!\/bin\/bash
                                #### 3.1 \u5b9a\u4e49\u57fa\u672c\u53d8\u91cf
                                INET_IF=”eth1″                     # \u5916\u7f51\u63a5\u53e3
                                INET_IP=”192.168.3.111″            # \u5916\u7f51\u63a5\u53e3\u5730\u5740
                                LAN_IF=”eth2″                      # \u5185\u7f51\u63a5\u53e3
                                LAN_IP=”192.168.1.4″               # \u5185\u7f51\u63a5\u53e3\u5730\u5740
                                LAN_NET=”192.168.1.0\/24″           # \u5185\u7f51\u7f51\u6bb5
                                LAN_WWW_IP=”192.168.3.112″         # \u7f51\u7ad9\u670d\u52a1\u5668\u7684\u5185\u90e8\u5730\u5740
                                IPT=”\/sbin\/iptables”               # iptables \u547d\u4ee4\u8def\u5f84
                                MOD=”\/sbin\/modprobe”               # modprobe \u547d\u4ee4\u8def\u5f84
                                CTL=”\/sbin\/sysctl”                 # sysctl \u547d\u4ee4\u8def\u5f84<\/p>\n\n\n\n

                                \u8bbe\u7f6e\u597d\u53d8\u91cf\u540e\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u5f15\u7528\u4e86\uff0c\u6dfb\u52a0\u5fc5\u8981\u7684\u6ce8\u91ca\u4ee5\u5916\uff0c\u53d8\u91cf\u540d\u79f0\u6700\u597d\u4f7f\u7528\u4e00\u5b9a\u542b\u4e49\u7684\u5b57\u7b26\u4e32\u3002<\/p>\n\n\n\n

                                3.2 <\/strong>\u52a0\u8f7d\u5185\u6838\u6a21\u5757<\/strong><\/strong><\/p>\n\n\n\n

                                iptables \u547d\u4ee4\u7684\u6a21\u5757\u90fd\u53ef\u4ee5\u6839\u636e\u9700\u8981\u52a8\u6001\u8f7d\u5165\u5185\u6838\uff0c\u4e2a\u522b\u9700\u8981\u624b\u52a8\u52a0\u8f7d\u3002<\/p>\n\n\n\n

                                \u9700\u542f\u7528\u7684\u89c4\u5219\u6570\u91cf\u591a\u65f6\uff0c\u53ef\u63d0\u9ad8\u89c4\u5219\u8bbe\u7f6e\u7684\u6548\u7387\uff0c\u4fdd\u6301\u9632\u706b\u5899\u7684\u7a33\u5b9a\u6027\uff0c\u5e76\u5c06\u5404\u6a21\u5757\u63d0\u524d\u52a0\u8f7d\u5230\u5185\u6838\u4e2d\u3002<\/p>\n\n\n\n

                                #### 3.2 \u52a0\u8f7d\u5fc5\u8981\u7684\u5185\u6838\u6a21\u5757
                                $MOD ip_tables                      # iptables \u57fa\u672c\u6a21\u5757
                                $MOD ip_conntrack                   # \u8fde\u63a5\u8ddf\u8e2a\u6a21\u5757
                                $MOD ipt_REJECT                     # \u62d2\u7edd\u64cd\u4f5c\u6a21\u5757
                                $MOD ipt_LOG                        # \u65e5\u5fd7\u8bb0\u5f55\u6a21\u5757
                                $MOD ipt_iprange                    # \u652f\u6301 IP \u8303\u56f4\u5339\u914d
                                $MOD xt_state                       # \u652f\u6301\u72b6\u6001\u5339\u914d
                                $MOD xt_multiport                   # \u652f\u6301\u591a\u7aef\u53e3\u5339\u914d
                                $MOD xt_mac                         # \u652f\u6301 MAC \u5730\u5740\u5339\u914d
                                $MOD ip_nat_ftp                     # \u652f\u6301 FTP \u5730\u5740\u8f6c\u6362
                                $MOD ip_conntrack_ftp               # \u652f\u6301 FTP \u8fde\u63a5\u8ddf\u8e2a<\/p>\n\n\n\n

                                3.3 <\/strong>\u8c03\u6574<\/strong> \/proc <\/strong>\u53c2\u6570<\/strong><\/strong><\/p>\n\n\n\n

                                \/proc \u662f Linux \u6216 UNIX \u7cfb\u7edf\u4e2d\u7684\u4e00\u79cd\u4f2a\u6587\u4ef6\u7cfb\u7edf\u673a\u5236\uff0c\u63d0\u4f9b\u8bbf\u95ee\u5185\u6838\u8fd0\u884c\u7ed3\u6784\u3001\u6539\u53d8\u5185\u6838\u8bbe\u7f6e\u7684\u5b9e\u65f6\u6570\u636e\u3002<\/p>\n\n\n\n

                                \/proc \u4e2d\u7684\u6570\u636e\u5b58\u653e\u5728\u5185\u5b58\u800c\u4e0d\u662f\u786c\u76d8\u4e0a\u3002<\/p>\n\n\n\n

                                \/proc\/sys \u5b58\u653e\u7740\u4e0e\u7cfb\u7edf\u76f8\u5173\u7684\u4e00\u4e9b\u53ef\u63a7\u53c2\u6570\uff0c\u53ef\u7528\u6765\u6539\u53d8\u5185\u6838\u7684\u884c\u4e3a\uff0c\u4f5c\u4e3a Linux \u5185\u6838\u8c03\u4f18\u7684\u5b9e\u65f6\u5165\u53e3\u3002<\/p>\n\n\n\n

                                \u4f7f\u7528echo\u3001sysctl \u547d\u4ee4\u53ef\u4ee5\u4fee\u6539\u76f8\u5173\u53c2\u6570\uff0c\u4e5f\u53ef\u4ee5\u5199\u5230\/etc\/sysctl.conf\u6587\u4ef6\u4e2d\uff0c\uff08\u6267\u884c sysctl -p \u540e\u751f\u6548\uff09\u5176\u4e3b\u8981\u5305\u62ec\u662f\u5426\u6253\u5f00 IP \u8f6c\u53d1\u3001\u662f\u5426\u54cd\u5e94 ICMP \u5e7f\u64ad\u3001\u8bbe\u7f6e\u597d TCP \u54cd\u5e94\u8d85\u65f6\u7b49\uff1b<\/p>\n\n\n\n

                                \u4ee5\u4e0b\u4e3a\u6700\u5e38\u89c1\u7684 \/proc \u53c2\u6570\u8c03\u6574<\/p>\n\n\n\n

                                icmp \u76f8\u5173\u53c2\u6570\uff1a\u53ef\u4f7f\u672c\u673a\u5ffd\u7565\u5176\u4ed6\u4e3b\u673a\u7684 ping \u6d4b\u8bd5\uff1b<\/p>\n\n\n\n

                                TCP \u76f8\u5173\u53c2\u6570\uff1a\u53ef\u9002\u5f53\u63d0\u9ad8\u672c\u673a\u62b5\u6297 DOS \u653b\u51fb\u7684\u80fd\u529b\uff1b<\/p>\n\n\n\n

                                #### 3.3 Linux \u5185\u6838\u63a7\u5236\u53ca\u8c03\u4f18
                                $CTL -w net.ipv4.ip_forward=1                     # \u6253\u5f00\u8def\u7531\u8f6c\u53d1\u529f\u80fd
                                $CTL -w net.ipv4.ip_default_ttl=128               # \u4fee\u6539 ICMP \u54cd\u5e94\u8d85\u65f6
                                $CTL -w net.ipv4.icmp_echo_ignore_all=1           # \u62d2\u7edd\u54cd\u5e94 ICMP \u8bf7\u6c42
                                $CTL -w net.ipv4.icmp_echo_ignore_broadcasts=1    # \u62d2\u7edd\u54cd\u5e94 ICMP \u5e7f\u64ad
                                $CTL -w net.ipv4.tcp_syncookies=1                 # \u542f\u7528 SYN Cookie \u673a\u5236
                                $CTL -w net.ipv4.tcp_syn_retries=3                # \u6700\u5927 SYN \u8bf7\u6c42\u91cd\u8bd5\u6b21\u6570
                                $CTL -w net.ipv4.tcp_synack_retries=3             # \u6700\u5927 ACK \u786e\u8ba4\u91cd\u8bd5\u6b21\u6570
                                $CTL -w net.ipv4.tcp_fin_timeout=60               # TCP \u8fde\u63a5\u7b49\u5f85\u8d85\u65f6
                                $CTL -w net.ipv4.tcp_max_syn_backlog=3200         # SYN \u8bf7\u6c42\u7684\u961f\u5217\u957f\u5ea6<\/p>\n\n\n\n

                                3.4 <\/strong>\u8bbe\u7f6e\u5177\u4f53\u7684<\/strong> iptables <\/strong>\u89c4\u5219<\/strong><\/strong><\/p>\n\n\n\n

                                \u6e05\u7406\u5df2\u6709\u7684\u89c4\u5219<\/strong><\/strong><\/p>\n\n\n\n

                                \u907f\u514d\u5df2\u6709\u7684\u9632\u706b\u5899\u89c4\u5219\u9020\u6210\u5e72\u6270\uff0c\u9700\u5148\u8fdb\u884c\u6e05\u7406\uff0c\u5220\u9664\u6240\u6709\u8868\u4e2d\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u94fe\uff0c\u6e05\u7a7a\u6240\u6709\u94fe\u5185\u7684\u89c4\u5219\u3002<\/p>\n\n\n\n

                                #### 3.4 \u5177\u4f53\u7684\u9632\u706b\u5899\u89c4\u5219
                                $IPT -t filter -X                                 # \u5220\u9664\u5404\u8868\u4e2d\u81ea\u5b9a\u4e49\u7684\u94fe
                                $IPT -t nat -X
                                $IPT -t filter -F                                 # \u6e05\u7a7a\u5404\u8868\u4e2d\u5df2\u6709\u7684\u89c4\u5219
                                $IPT -t nat -F<\/p>\n\n\n\n

                                \u8bbe\u7f6e\u89c4\u5219\u94fe\u7684\u9ed8\u8ba4\u7b56\u7565<\/strong><\/strong><\/p>\n\n\n\n

                                \u5b9e\u9645\u73af\u5883\u4e2d\uff0c\u9632\u706b\u5899\u8fc7\u6ee4\u89c4\u5219\u9700\u91c7\u53d6\u9ed8\u8ba4\u62d2\u7edd\u7684\u7b56\u7565\uff0c\u53ef\u63d0\u9ad8\u5b89\u5168\u6027\u3002<\/p>\n\n\n\n

                                \u5b66\u4e60\u8fc7\u7a0b\u4e2d\uff0c\u8fd8\u662f\u5efa\u8bae\u91c7\u53d6\u9ed8\u8ba4\u5141\u8bb8\u7684\u7b56\u7565\uff0c\u9700\u5c06\u9ed8\u8ba4\u7b56\u7565\u4e2d\u7684DROP\u6539\u4e3aACCEPT\u3002<\/p>\n\n\n\n

                                $IPT -P INPUT DROP
                                $IPT -P FORWARD DROP
                                $IPT -P OUTPUT ACCEPT<\/p>\n\n\n\n

                                \u8bbe\u7f6e<\/strong> nat <\/strong>\u8868\u4e2d\u7684\u5404\u79cd\u89c4\u5219<\/strong><\/strong><\/p>\n\n\n\n

                                nat \u8868\u4e3b\u8981\u7528\u5728 Linux \u7f51\u5173\u670d\u52a1\u5668\u4e2d\uff0c\u9700\u6839\u636e\u5b9e\u9645\u60c5\u51b5\u7f16\u5199\u76f8\u5e94\u7684SNAT\u548cDNAT\u89c4\u5219\u3002<\/p>\n\n\n\n

                                $IPT -t nat -A POSTROUTING -s $LAN_NET -o $INET_IF -j SNAT –to-source $INET_IP
                                $IPT -t nat -A PREROUTING -i $INET_IF -d $INET_IP -p tcp –dport 80 -j DNAT –to-destination $LAN_WWW_IP<\/p>\n\n\n\n

                                \u8bbe\u7f6e<\/strong> filter <\/strong>\u8868\u4e2d\u7684\u5404\u79cd\u89c4\u5219<\/strong><\/strong><\/p>\n\n\n\n

                                filter \u8868\u4e3b\u8981\u7528\u6765\u8fc7\u6ee4\u6570\u636e\u5305\u3002<\/p>\n\n\n\n

                                \u4e3b\u673a\u578b\u9632\u706b\u5899\u4e3b\u8981\u4f7f\u7528INPUT\u548cOUTPUT\u94fe\u3002<\/p>\n\n\n\n

                                \u7f51\u7edc\u578b\u9632\u706b\u5899\u4e3b\u8981\u4f7f\u7528FORWARD\u94fe\u3002<\/p>\n\n\n\n

                                \u9ed8\u8ba4\u62d2\u7edd\u7684\u60c5\u51b5\u4e0b\uff0c\u8981\u5b9e\u73b0\u5171\u4eab\u4e0a\u7f51\uff0c\u9664\u4e86\u8bbe\u7f6eSNAT\u7b56\u7565\u5916\uff0c\u8fd8\u9700\u653e\u884c\u5185\u7f51 PC \u4e0e Internet \u4e2d\u7684 DNS\u3001HTTPD \u7b49\u76f8\u5173\u670d\u52a1\u901a\u4fe1\uff1b<\/p>\n\n\n\n

                                \u6ce8\u610f\uff1a\u5728\u5b9e\u9645\u5de5\u4f5c\u4e2d\uff0c\u5efa\u8bae\u5927\u5bb6\u8fd8\u662f\u6839\u636e\u5b9e\u9645\u7f51\u7edc\u60c5\u51b5\u8fdb\u884c\u8bbe\u7f6e\u76f8\u5e94\u7684\u89c4\u5219\uff0c\u5e76\u5728\u6d4b\u8bd5\u73af\u5883\u4e2d\u8fdb\u884c\u6d4b\u8bd5\uff0c\u786e\u4fdd\u89c4\u5219\u65e0\u8bef\uff0c\u907f\u514d\u5bfc\u81f4\u7f51\u7edc\u901a\u4fe1\u51fa\u73b0\u6545\u969c\u3002<\/strong><\/p>\n\n\n\n

                                $IPT -A FOEWARD -s $LAN_NET -o $INET_IF -p udp 53 -j ACCEPT
                                $IPT -A FOEWARD -s $LAN_NET -o $INET_IF -p udp 80 -j ACCEPT
                                $IPT -A FOEWARD -d $LAN_NET -i $INET_IF -m state ESTABLISHED,RELATED -j ACCEPT<\/p>\n\n\n\n

                                \u6dfb\u52a0\u6267\u884c\u6743\u9650<\/p>\n\n\n\n

                                # chmod +x \/opt\/myiptables.sh <\/p>\n\n\n\n

                                \u6267\u884c\/opt\/myiptables.sh\u811a\u672c\u6587\u4ef6<\/p>\n\n\n\n

                                # \/opt\/myiptables.sh 
                                net.ipv4.ip_forward = 1
                                net.ipv4.ip_default_ttl = 128
                                net.ipv4.icmp_echo_ignore_all = 1
                                net.ipv4.icmp_echo_ignore_broadcasts = 1
                                net.ipv4.tcp_syncookies = 1
                                net.ipv4.tcp_syn_retries = 3
                                net.ipv4.tcp_synack_retries = 3
                                net.ipv4.tcp_fin_timeout = 60
                                net.ipv4.tcp_max_syn_backlog = 3200<\/p>\n\n\n\n

                                \u67e5\u770b\u9632\u706b\u5899\u89c4\u5219<\/p>\n\n\n\n

                                # iptables -nL FORWARD<\/p>\n\n\n\n

                                \u5c06\/opt\/myiptables.sh\u811a\u672c\u6587\u4ef6\u8bbe\u7f6e\u4e3a\u5f00\u673a\u81ea\u52a8\u6267\u884c<\/p>\n\n\n\n

                                # vi \/etc\/rc.local
                                \/opt\/myiptables.sh<\/p>\n\n\n\n

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

                                \u8f6c\u8f7d\u539f\u6587\u94fe\u63a5\uff1ahttps:\/\/www.eet-china.com\/mp\/a31036.html<\/p>\n","protected":false},"excerpt":{"rendered":"

                                Linux iptables \u8be6\u89e3 \uff08\u4e00\uff09- \u56db\u8868\/\u4e94\u94fe\u3001\u6570\u636e\u5305\u5339\u914d\u6d41\u7a0b\u3001\u7f16\u5199 iptables \u89c4\u5219 1.L […]<\/p>\n","protected":false},"author":1,"featured_media":2134,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[153],"tags":[235,158,236],"class_list":["post-2118","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-153","tag-iptables","tag-linux","tag-linux-iptables"],"_links":{"self":[{"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/posts\/2118","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/comments?post=2118"}],"version-history":[{"count":3,"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/posts\/2118\/revisions"}],"predecessor-version":[{"id":2138,"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/posts\/2118\/revisions\/2138"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/media\/2134"}],"wp:attachment":[{"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/media?parent=2118"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/categories?post=2118"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.menshours.com\/index.php\/wp-json\/wp\/v2\/tags?post=2118"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}