{"id":161,"date":"2010-12-10T23:47:03","date_gmt":"2010-12-10T15:47:03","guid":{"rendered":"http:\/\/www.microwolf.net\/?p=161"},"modified":"2010-12-10T23:47:03","modified_gmt":"2010-12-10T15:47:03","slug":"linux-iptables-%e8%ae%be%e7%bd%ae","status":"publish","type":"post","link":"http:\/\/www.microwolf.net\/?p=161","title":{"rendered":"Linux iptables \u8bbe\u7f6e"},"content":{"rendered":"\n\n
\n

\n\u4e00\u3001\u6982\u8ff0<\/p>\n

1. \u4ec0\u4e48\u662fNAT

\n\u5728\u4f20\u7edf\u7684\u6807\u51c6\u7684TCP\/IP\u901a\u4fe1\u8fc7\u7a0b\u4e2d\uff0c\u6240\u6709\u7684\u8def\u7531\u5668\u4ec5\u4ec5\u662f\u5145\u5f53\u4e00\u4e2a\u4e2d\u95f4\u4eba\u7684\u89d2\u8272\uff0c\u4e5f\u5c31\u662f\u901a\u5e38\u6240\u8bf4\u7684\u5b58\u50a8\u8f6c\u53d1\uff0c\u8def\u7531\u5668\u5e76\u4e0d\u4f1a\u5bf9\u8f6c\u53d1\u7684\u6570\u636e\u5305\u8fdb\u884c\u4fee\u6539\uff0c\u66f4\u4e3a\u786e\u5207\u7684\u8bf4\uff0c\u9664\u4e86\u5c06\u6e90MAC\u5730\u5740\u6362\u6210\u81ea\u5df1\u7684MAC\u5730\u5740\u4ee5\u5916\uff0c\u8def\u7531\u5668\u4e0d\u4f1a\u5bf9\u8f6c\u53d1\u7684\u6570\u636e\u5305\u505a\u4efb\u4f55\u4fee\u6539\u3002NAT(Network Address Translation\u7f51\u7edc\u5730\u5740\u7ffb\u8bd1)\u6070\u6070\u662f\u51fa\u4e8e\u67d0\u79cd\u7279\u6b8a\u9700\u8981\u800c\u5bf9\u6570\u636e\u5305\u7684\u6e90ip\u5730\u5740\u3001\u76ee\u7684ip\u5730\u5740\u3001\u6e90\u7aef\u53e3\u3001\u76ee\u7684\u7aef\u53e3\u8fdb\u884c\u6539\u5199\u7684\u64cd\u4f5c\u3002<\/p>\n

2. \u4e3a\u4ec0\u4e48\u8981\u8fdb\u884cNAT

\n\u6211\u4eec\u6765\u770b\u770b\u518d\u4ec0\u4e48\u60c5\u51b5\u4e0b\u6211\u4eec\u9700\u8981\u505aNAT\u3002
\n\u5047\u8bbe\u6709\u4e00\u5bb6ISP\u63d0\u4f9b\u56ed\u533aInternet\u63a5\u5165\u670d\u52a1\uff0c\u4e3a\u4e86\u65b9\u4fbf\u7ba1\u7406\uff0c\u8be5ISP\u5206\u914d\u7ed9\u56ed\u533a\u7528\u6237\u7684IP\u5730\u5740\u90fd\u662f\u4f2aIP\uff0c\u4f46\u662f\u90e8\u5206\u7528\u6237\u8981\u6c42\u5efa\u7acb\u81ea\u5df1\u7684WWW\u670d\u52a1\u5668\u5bf9\u5916\u53d1\u5e03\u4fe1\u606f\uff0c\u8fd9\u65f6\u5019\u6211\u4eec\u5c31\u53ef\u4ee5\u901a\u8fc7NAT\u6765\u63d0\u4f9b\u8fd9\u79cd\u670d\u52a1\u4e86\u3002\u6211\u4eec\u53ef\u4ee5\u518d\u9632\u706b\u5899\u7684\u5916\u90e8\u7f51\u5361\u4e0a\u7ed1\u5b9a\u591a\u4e2a\u5408\u6cd5IP\u5730\u5740\uff0c\u7136\u540e\u901a\u8fc7NAT\u6280\u672f\u4f7f\u53d1\u7ed9\u5176\u4e2d\u67d0\u4e00\u4e2aIP\u5730\u5740\u7684\u5305\u8f6c\u53d1\u81f3\u5185\u90e8\u67d0\u4e00\u7528\u6237\u7684WWW\u670d\u52a1\u5668\u4e0a\uff0c\u7136\u540e\u518d\u5c06\u8be5\u5185\u90e8WWW\u670d\u52a1\u5668\u54cd\u5e94\u5305\u4f2a\u88c5\u6210\u8be5\u5408\u6cd5IP\u53d1\u51fa\u7684\u5305\u3002
\n\u518d\u6bd4\u5982\u4f7f\u7528\u62e8\u53f7\u4e0a\u7f51\u7684\u7f51\u5427\uff0c\u56e0\u4e3a\u53ea\u6709\u4e00\u4e2a\u5408\u6cd5\u7684IP\u5730\u5740\uff0c\u5fc5\u987b\u91c7\u7528\u67d0\u79cd\u624b\u6bb5\u8ba9\u5176\u4ed6\u673a\u5668\u4e5f\u53ef\u4ee5\u4e0a\u7f51\uff0c\u901a\u5e38\u662f\u91c7\u7528\u4ee3\u7406\u670d\u52a1\u5668\u7684\u65b9\u5f0f\uff0c\u4f46\u662f\u4ee3\u7406\u670d\u52a1\u5668\uff0c\u5c24\u5176\u662f\u5e94\u7528\u5c42\u4ee3\u7406\u670d\u52a1\u5668\uff0c\u53ea\u80fd\u652f\u6301\u6709\u9650\u7684\u534f\u8bae\uff0c\u5982\u679c\u8fc7\u4e86\u4e00\u6bb5\u65f6\u95f4\u540e\u53c8\u6709\u65b0\u7684\u670d\u52a1\u51fa\u6765\uff0c\u5219\u53ea\u80fd\u7b49\u5f85\u4ee3\u7406\u670d\u52a1\u5668\u652f\u6301\u8be5\u65b0\u5e94\u7528\u7684\u5347\u7ea7\u7248\u672c\u3002\u5982\u679c\u91c7\u7528NAT\u6765\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c
\n\u56e0\u4e3a\u53ea\u5728\u5e94\u7528\u5c42\u4ee5\u4e0b\u8fdb\u884c\u5904\u7406\uff0c\u4e0d\u4f46\u53ef\u4ee5\u83b7\u5f97\u5f88\u9ad8\u7684\u8bbf\u95ee\u901f\u5ea6\uff0c\u800c\u4e14\u53ef\u4ee5\u65e0\u7f1d\u7684\u652f\u6301\u4efb\u4f55\u65b0\u7684\u670d\u52a1\u6216\u5e94\u7528\u3002
\n\u8fd8\u6709\u4e00\u4e2a\u65b9\u9762\u7684\u5e94\u7528\u5c31\u662f\u91cd\u5b9a\u5411\uff0c\u4e5f\u5c31\u662f\u5f53\u63a5\u6536\u5230\u4e00\u4e2a\u5305\u540e\uff0c\u4e0d\u662f\u8f6c\u53d1\u8fd9\u4e2a\u5305\uff0c\u800c\u662f\u5c06\u5176\u91cd\u5b9a\u5411\u5230\u7cfb\u7edf\u4e0a\u7684\u67d0\u4e00\u4e2a\u5e94\u7528\u7a0b\u5e8f\u3002\u6700\u5e38\u89c1\u7684\u5e94\u7528\u5c31\u662f\u548csquid\u914d\u5408\u4f7f\u7528\u6210\u4e3a\u900f\u660e\u4ee3\u7406\uff0c\u5728\u5bf9http\u6d41\u91cf\u8fdb\u884c\u7f13\u5b58\u7684\u540c\u65f6\uff0c\u53ef\u4ee5\u63d0\u4f9b\u5bf9Internet\u7684\u65e0\u7f1d\u8bbf\u95ee\u3002<\/p>\n

3. NAT\u7684\u7c7b\u578b

\n\u5728linux2.4\u7684NAT-HOWTO\u4e2d\uff0c\u4f5c\u8005\u4ece\u539f\u7406\u7684\u89d2\u5ea6\u5c06NAT\u5206\u6210\u4e86\u4e24\u79cd\u7c7b\u578b\uff0c\u5373\u6e90NAT(SNAT)\u548c\u76ee\u7684NAT(DNAT)\uff0c\u987e\u540d\u601d\u4e49\uff0c\u6240\u8c13SNAT\u5c31\u662f\u6539\u53d8\u8f6c\u53d1\u6570\u636e\u5305\u7684\u6e90\u5730\u5740\uff0c\u6240\u8c13DNAT\u5c31\u662f\u6539\u53d8\u8f6c\u53d1\u6570\u636e\u5305\u7684\u76ee\u7684\u5730\u5740\u3002<\/p>\n

\u4e8c\u3001\u539f\u7406\n<\/p>\n

netfilter\u662fLinux \u6838\u5fc3\u4e2d\u4e00\u4e2a\u901a\u7528\u67b6\u6784\uff0c\u5b83\u63d0\u4f9b\u4e86\u4e00\u7cfb\u5217\u7684”\u8868”(tables)\uff0c\u6bcf\u4e2a\u8868\u7531\u82e5\u5e72”\u94fe”(chains)\u7ec4\u6210\uff0c\u800c\u6bcf\u6761\u94fe\u4e2d\u53ef\u4ee5\u6709\u4e00\u6761\u6216\u6570\u6761\u89c4\u5219(rule)\u7ec4\u6210\u3002\u5e76\u4e14\u7cfb\u7edf\u7f3a\u7701\u7684\u8868\u662f”filter”\u3002\u4f46\u662f\u5728\u4f7f\u7528NAT\u7684\u65f6\u5019\uff0c\u6211\u4eec\u6240\u4f7f\u7528\u7684\u8868\u4e0d\u518d\u662f”filter”\uff0c\u800c\u662f”nat”\u8868\uff0c\u6240\u4ee5\u6211\u4eec\u5fc5\u987b\u4f7f\u7528”-t nat”\u9009\u9879\u6765\u663e\u5f0f\u5730\u6307\u660e\u8fd9\u4e00\u70b9\u3002\u56e0\u4e3a\u7cfb\u7edf\u7f3a\u7701\u7684\u8868\u662f”filter”\uff0c\u6240\u4ee5\u5728\u4f7f\u7528filter\u529f\u80fd\u65f6\uff0c\u6211\u4eec\u6ca1\u6709\u5fc5\u8981\u663e\u5f0f\u7684\u6307\u660e”-t filter”\u3002

\n\u540cfilter\u8868\u4e00\u6837\uff0cnat\u8868\u4e5f\u6709\u4e09\u6761\u7f3a\u7701\u7684”\u94fe”(chains)\uff0c\u8fd9\u4e09\u6761\u94fe\u4e5f\u662f\u89c4\u5219\u7684\u5bb9\u5668\uff0c\u5b83\u4eec\u5206\u522b\u662f\uff1a
\nPREROUTING\uff1a\u53ef\u4ee5\u5728\u8fd9\u91cc\u5b9a\u4e49\u8fdb\u884c\u76ee\u7684NAT\u7684\u89c4\u5219\uff0c\u56e0\u4e3a\u8def\u7531\u5668\u8fdb\u884c\u8def\u7531\u65f6\u53ea\u68c0\u67e5\u6570\u636e\u5305\u7684\u76ee\u7684ip\u5730\u5740\uff0c\u6240\u4ee5\u4e3a\u4e86\u4f7f\u6570\u636e\u5305\u5f97\u4ee5\u6b63\u786e\u8def\u7531\uff0c\u6211\u4eec\u5fc5\u987b\u5728\u8def\u7531\u4e4b\u524d\u5c31\u8fdb\u884c\u76ee\u7684NAT;
\nPOSTROUTING\uff1a\u53ef\u4ee5\u5728\u8fd9\u91cc\u5b9a\u4e49\u8fdb\u884c\u6e90NAT\u7684\u89c4\u5219\uff0c\u7cfb\u7edf\u5728\u51b3\u5b9a\u4e86\u6570\u636e\u5305\u7684\u8def\u7531\u4ee5\u540e\u5728\u6267\u884c\u8be5\u94fe\u4e2d\u7684\u89c4\u5219\u3002
\nOUTPUT\uff1a\u5b9a\u4e49\u5bf9\u672c\u5730\u4ea7\u751f\u7684\u6570\u636e\u5305\u7684\u76ee\u7684NAT\u89c4\u5219\u3002<\/p>\n

\u4e09\u3001\u64cd\u4f5c\u8bed\u6cd5<\/p>\n

\u5982\u524d\u6240\u8ff0\uff0c\u5728\u4f7f\u7528iptables\u7684NAT\u529f\u80fd\u65f6\uff0c\u6211\u4eec\u5fc5\u987b\u5728\u6bcf\u4e00\u6761\u89c4\u5219\u4e2d\u4f7f\u7528”-t nat”\u663e\u793a\u7684\u6307\u660e\u4f7f\u7528nat\u8868\u3002\u7136\u540e\u4f7f\u7528\u4ee5\u4e0b\u7684\u9009\u9879:<\/p>\n

1. \u5bf9\u89c4\u5219\u7684\u64cd\u4f5c

\n\u52a0\u5165(append) \u4e00\u4e2a\u65b0\u89c4\u5219\u5230\u4e00\u4e2a\u94fe (-A)\u7684\u6700\u540e\u3002

\n\u5728\u94fe\u5185\u67d0\u4e2a\u4f4d\u7f6e\u63d2\u5165(insert) \u4e00\u4e2a\u65b0\u89c4\u5219(-I)\uff0c\u901a\u5e38\u662f\u63d2\u5728\u6700\u524d\u9762\u3002

\n\u5728\u94fe\u5185\u67d0\u4e2a\u4f4d\u7f6e\u66ff\u6362(replace) \u4e00\u6761\u89c4\u5219 (-R)\u3002

\n\u5728\u94fe\u5185\u67d0\u4e2a\u4f4d\u7f6e\u5220\u9664(delete) \u4e00\u6761\u89c4\u5219 (-D)\u3002

\n\u5220\u9664(delete) \u94fe\u5185\u7b2c\u4e00\u6761\u89c4\u5219 (-D)\u3002 <\/p>\n

2. \u6307\u5b9a\u6e90\u5730\u5740\u548c\u76ee\u7684\u5730\u5740<\/p>\n

\u901a\u8fc7–source\/–src\/-s\u6765\u6307\u5b9a\u6e90\u5730\u5740(\u8fd9\u91cc\u7684\/\u8868\u793a\u6216\u8005\u7684\u610f\u601d\uff0c\u4e0b\u540c)\uff0c\u901a\u8fc7–destination\/–dst\/-d\u6765\u6307\u5b9a\u76ee\u7684\u5730\u5740\u3002\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u56db\u4e2d\u65b9\u6cd5\u6765\u6307\u5b9aip\u5730\u5740\uff1a
\na. \u4f7f\u7528\u5b8c\u6574\u7684\u57df\u540d\uff0c\u5982\u201cwww.linuxaid.com.cn\u201d\uff1b

\nb. \u4f7f\u7528ip\u5730\u5740\uff0c\u5982\u201c192.168.1.1\u201d\uff1b

\nc. \u7528x.x.x.x\/x.x.x.x\u6307\u5b9a\u4e00\u4e2a\u7f51\u7edc\u5730\u5740\uff0c\u5982\u201c192.168.1.0\/255.255.255.0\u201d;

\nd. \u7528x.x.x.x\/x\u6307\u5b9a\u4e00\u4e2a\u7f51\u7edc\u5730\u5740\uff0c\u5982\u201c192.168.1.0\/24\u201d\u8fd9\u91cc\u768424\u8868\u660e\u4e86\u5b50\u7f51\u63a9\u7801\u7684\u6709\u6548\u4f4d\u6570\uff0c\u8fd9\u662f UNIX\u73af\u5883\u4e2d\u901a\u5e38\u4f7f\u7528\u7684\u8868\u793a\u65b9\u6cd5\u3002

\n\u7f3a\u7701\u7684\u5b50\u7f51\u63a9\u7801\u6570\u662f32\uff0c\u4e5f\u5c31\u662f\u8bf4\u6307\u5b9a192.168.1.1\u7b49\u6548\u4e8e192.168.1.1\/32\u3002 <\/p>\n

\n3. \u6307\u5b9a\u7f51\u7edc\u63a5\u53e3<\/p>\n

\u53ef\u4ee5\u4f7f\u7528–in-interface\/-i\u6216–out-interface\/-o\u6765\u6307\u5b9a\u7f51\u7edc\u63a5\u53e3\u3002\u4eceNAT\u7684\u539f\u7406\u53ef\u4ee5\u770b\u51fa\uff0c\u5bf9\u4e8ePREROUTING\u94fe\uff0c\u6211\u4eec\u53ea\u80fd\u7528-i\u6307\u5b9a\u8fdb\u6765\u7684\u7f51\u7edc\u63a5\u53e3\uff1b\u800c\u5bf9\u4e8ePOSTROUTING\u548cOUTPUT\u6211\u4eec\u53ea\u80fd\u7528-o\u6307\u5b9a\u51fa\u53bb\u7684\u7f51\u7edc\u63a5\u53e3\u3002<\/p>\n

4. \u6307\u5b9a\u534f\u8bae\u53ca\u7aef\u53e3<\/p>\n

\u53ef\u4ee5\u901a\u8fc7–protocol\/-p\u9009\u9879\u6765\u6307\u5b9a\u534f\u8bae\uff0c\u5982\u679c\u662fudp\u548ctcp\u534f\u8bae\uff0c\u8fd8\u53ef–source-port\/–sport\u548c –destination-port\/–dport\u6765\u6307\u660e\u7aef\u53e3\u3002\n<\/p>\n

\u8be6\u89e3\uff1a\n<\/p>\n

\u5efa\u7acb\u89c4\u5219\u548c\u94fe
\n\u901a\u8fc7\u5411\u9632\u706b\u5899\u63d0\u4f9b\u6709\u5173\u5bf9\u6765\u81ea\u67d0\u4e2a\u6e90\u3001\u5230\u67d0\u4e2a\u76ee\u7684\u5730\u6216\u5177\u6709\u7279\u5b9a\u534f\u8bae\u7c7b\u578b\u7684\u4fe1\u606f\u5305\u8981\u505a\u4e9b\u4ec0\u4e48\u7684\u6307\u4ee4\uff0c\u89c4\u5219\u63a7\u5236\u4fe1\u606f\u5305\u7684\u8fc7\u6ee4\u3002\u901a\u8fc7\u4f7f\u7528 netfilter\/iptables \u7cfb\u7edf\u63d0\u4f9b\u7684\u7279\u6b8a\u547d\u4ee4 iptables\uff0c\u5efa\u7acb\u8fd9\u4e9b\u89c4\u5219\uff0c\u5e76\u5c06\u5176\u6dfb\u52a0\u5230\u5185\u6838\u7a7a\u95f4\u7684\u7279\u5b9a\u4fe1\u606f\u5305\u8fc7\u6ee4\u8868\u5185\u7684\u94fe\u4e2d\u3002\u5173\u4e8e\u6dfb\u52a0\uff0f\u9664\u53bb\uff0f\u7f16\u8f91\u89c4\u5219\u7684\u547d\u4ee4\u7684\u4e00\u822c\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n

$ iptables [-t table] command [match] [target] <\/p>\n

\u8868\uff08table\uff09
\n[-t table] \u9009\u9879\u5141\u8bb8\u4f7f\u7528\u6807\u51c6\u8868\u4e4b\u5916\u7684\u4efb\u4f55\u8868\u3002\u8868\u662f\u5305\u542b\u4ec5\u5904\u7406\u7279\u5b9a\u7c7b\u578b\u4fe1\u606f\u5305\u7684\u89c4\u5219\u548c\u94fe\u7684\u4fe1\u606f\u5305\u8fc7\u6ee4\u8868\u3002\u6709\u4e09\u79cd\u53ef\u7528\u7684\u8868\u9009\u9879\uff1afilter\u3001nat \u548c mangle\u3002\u8be5\u9009\u9879\u4e0d\u662f\u5fc5\u9700\u7684\uff0c\u5982\u679c\u672a\u6307\u5b9a\uff0c\u5219 filter \u7528\u4f5c\u7f3a\u7701\u8868\u3002 <\/p>\n

filter \u8868\u7528\u4e8e\u4e00\u822c\u7684\u4fe1\u606f\u5305\u8fc7\u6ee4\uff0c\u5b83\u5305\u542b INPUT\u3001OUTPUT \u548c FORWARD \u94fe\u3002nat \u8868\u7528\u4e8e\u8981\u8f6c\u53d1\u7684\u4fe1\u606f\u5305\uff0c\u5b83\u5305\u542b PREROUTING\u3001OUTPUT \u548c POSTROUTING \u94fe\u3002\u5982\u679c\u4fe1\u606f\u5305\u53ca\u5176\u5934\u5185\u8fdb\u884c\u4e86\u4efb\u4f55\u66f4\u6539\uff0c\u5219\u4f7f\u7528 mangle \u8868\u3002\u8be5\u8868\u5305\u542b\u4e00\u4e9b\u89c4\u5219\u6765\u6807\u8bb0\u7528\u4e8e\u9ad8\u7ea7\u8def\u7531\u7684\u4fe1\u606f\u5305\uff0c\u8be5\u8868\u5305\u542b PREROUTING \u548c OUTPUT \u94fe\u3002 <\/p>\n

\u6ce8\uff1aPREROUTING \u94fe\u7531\u6307\u5b9a\u4fe1\u606f\u5305\u4e00\u5230\u8fbe\u9632\u706b\u5899\u5c31\u6539\u53d8\u5b83\u4eec\u7684\u89c4\u5219\u6240\u7ec4\u6210\uff0c\u800c POSTROUTING \u94fe\u7531\u6307\u5b9a\u6b63\u5f53\u4fe1\u606f\u5305\u6253\u7b97\u79bb\u5f00\u9632\u706b\u5899\u65f6\u6539\u53d8\u5b83\u4eec\u7684\u89c4\u5219\u6240\u7ec4\u6210\u3002 <\/p>\n

\u547d\u4ee4\uff08command\uff09
\n\u4e0a\u9762\u8fd9\u6761\u547d\u4ee4\u4e2d\u5177\u6709\u5f3a\u5236\u6027\u7684 command \u90e8\u5206\u662f iptables \u547d\u4ee4\u7684\u6700\u91cd\u8981\u90e8\u5206\u3002\u5b83\u544a\u8bc9 iptables \u547d\u4ee4\u8981\u505a\u4ec0\u4e48\uff0c\u4f8b\u5982\uff0c\u63d2\u5165\u89c4\u5219\u3001\u5c06\u89c4\u5219\u6dfb\u52a0\u5230\u94fe\u7684\u672b\u5c3e\u6216\u5220\u9664\u89c4\u5219\u3002\u4ee5\u4e0b\u662f\u6700\u5e38\u7528\u7684\u4e00\u4e9b\u547d\u4ee4\uff1a<\/p>\n

-A \u6216 –append\uff1a\u8be5\u547d\u4ee4\u5c06\u4e00\u6761\u89c4\u5219\u9644\u52a0\u5230\u94fe\u7684\u672b\u5c3e\u3002

\n\u793a\u4f8b\uff1a
\n$ iptables -A INPUT -s 205.168.0.1 -j ACCEPT <\/p>\n

\u8be5\u793a\u4f8b\u547d\u4ee4\u5c06\u4e00\u6761\u89c4\u5219\u9644\u52a0\u5230 INPUT \u94fe\u7684\u672b\u5c3e\uff0c\u786e\u5b9a\u6765\u81ea\u6e90\u5730\u5740 205.168.0.1 \u7684\u4fe1\u606f\u5305\u53ef\u4ee5 ACCEPT\u3002 <\/p>\n

\n-D \u6216 –delete\uff1a\u901a\u8fc7\u7528 -D \u6307\u5b9a\u8981\u5339\u914d\u7684\u89c4\u5219\u6216\u8005\u6307\u5b9a\u89c4\u5219\u5728\u94fe\u4e2d\u7684\u4f4d\u7f6e\u7f16\u53f7\uff0c\u8be5\u547d\u4ee4\u4ece\u94fe\u4e2d\u5220\u9664\u8be5\u89c4\u5219\u3002\u4e0b\u9762\u7684\u793a\u4f8b\u663e\u793a\u4e86\u8fd9\u4e24\u79cd\u65b9\u6cd5\u3002

\n\u793a\u4f8b\uff1a
\n$ iptables -D INPUT –dport 80 -j DROP

\n$ iptables -D OUTPUT 3 <\/p>\n

\u7b2c\u4e00\u6761\u547d\u4ee4\u4ece INPUT \u94fe\u5220\u9664\u89c4\u5219\uff0c\u5b83\u6307\u5b9a DROP \u524d\u5f80\u7aef\u53e3 80 \u7684\u4fe1\u606f\u5305\u3002\u7b2c\u4e8c\u6761\u547d\u4ee4\u53ea\u662f\u4ece OUTPUT \u94fe\u5220\u9664\u7f16\u53f7\u4e3a 3 \u7684\u89c4\u5219\u3002 <\/p>\n

\n-P \u6216 –policy\uff1a\u8be5\u547d\u4ee4\u8bbe\u7f6e\u94fe\u7684\u7f3a\u7701\u76ee\u6807\uff0c\u5373\u7b56\u7565\u3002\u6240\u6709\u4e0e\u94fe\u4e2d\u4efb\u4f55\u89c4\u5219\u90fd\u4e0d\u5339\u914d\u7684\u4fe1\u606f\u5305\u90fd\u5c06\u88ab\u5f3a\u5236\u4f7f\u7528\u6b64\u94fe\u7684\u7b56\u7565\u3002

\n\u793a\u4f8b\uff1a
\n$ iptables -P INPUT DROP <\/p>\n

\u8be5\u547d\u4ee4\u5c06 INPUT \u94fe\u7684\u7f3a\u7701\u76ee\u6807\u6307\u5b9a\u4e3a DROP\u3002\u8fd9\u610f\u5473\u7740\uff0c\u5c06\u4e22\u5f03\u6240\u6709\u4e0e INPUT \u94fe\u4e2d\u4efb\u4f55\u89c4\u5219\u90fd\u4e0d\u5339\u914d\u7684\u4fe1\u606f\u5305\u3002 <\/p>\n

\n-N \u6216 –new-chain\uff1a\u7528\u547d\u4ee4\u4e2d\u6240\u6307\u5b9a\u7684\u540d\u79f0\u521b\u5efa\u4e00\u4e2a\u65b0\u94fe\u3002

\n\u793a\u4f8b\uff1a
\n$ iptables -N allowed-chain <\/p>\n

-F \u6216 –flush\uff1a\u5982\u679c\u6307\u5b9a\u94fe\u540d\uff0c\u8be5\u547d\u4ee4\u5220\u9664\u94fe\u4e2d\u7684\u6240\u6709\u89c4\u5219\uff0c\u5982\u679c\u672a\u6307\u5b9a\u94fe\u540d\uff0c\u8be5\u547d\u4ee4\u5220\u9664\u6240\u6709\u94fe\u4e2d\u7684\u6240\u6709\u89c4\u5219\u3002\u6b64\u53c2\u6570\u7528\u4e8e\u5feb\u901f\u6e05\u9664\u3002

\n\u793a\u4f8b\uff1a
\n$ iptables -F FORWARD

\n$ iptables -F <\/p>\n

-L \u6216 –list\uff1a\u5217\u51fa\u6307\u5b9a\u94fe\u4e2d\u7684\u6240\u6709\u89c4\u5219\u3002

\n\u793a\u4f8b\uff1a
\n$ iptables -L allowed-chain <\/p>\n

\u5339\u914d\uff08match\uff09
\niptables \u547d\u4ee4\u7684\u53ef\u9009 match \u90e8\u5206\u6307\u5b9a\u4fe1\u606f\u5305\u4e0e\u89c4\u5219\u5339\u914d\u6240\u5e94\u5177\u6709\u7684\u7279\u5f81\uff08\u5982\u6e90\u548c\u76ee\u7684\u5730\u5730\u5740\u3001\u534f\u8bae\u7b49\uff09\u3002\u5339\u914d\u5206\u4e3a\u4e24\u5927\u7c7b\uff1a\u901a\u7528\u5339\u914d\u548c\u7279\u5b9a\u4e8e\u534f\u8bae\u7684\u5339\u914d\u3002\u8fd9\u91cc\uff0c\u6211\u5c06\u7814\u7a76\u53ef\u7528\u4e8e\u91c7\u7528\u4efb\u4f55\u534f\u8bae\u7684\u4fe1\u606f\u5305\u7684\u901a\u7528\u5339\u914d\u3002\u4e0b\u9762\u662f\u4e00\u4e9b\u91cd\u8981\u7684\u4e14\u5e38\u7528\u7684\u901a\u7528\u5339\u914d\u53ca\u5176\u793a\u4f8b\u548c\u8bf4\u660e\uff1a<\/p>\n

-p \u6216 –protocol\uff1a\u8be5\u901a\u7528\u534f\u8bae\u5339\u914d\u7528\u4e8e\u68c0\u67e5\u67d0\u4e9b\u7279\u5b9a\u534f\u8bae\u3002\u534f\u8bae\u793a\u4f8b\u6709 TCP\u3001UDP\u3001ICMP\u3001\u7528\u9017\u53f7\u5206\u9694\u7684\u4efb\u4f55\u8fd9\u4e09\u79cd\u534f\u8bae\u7684\u7ec4\u5408\u5217\u8868\u4ee5\u53ca ALL\uff08\u7528\u4e8e\u6240\u6709\u534f\u8bae\uff09\u3002ALL \u662f\u7f3a\u7701\u5339\u914d\u3002\u53ef\u4ee5\u4f7f\u7528 ! \u7b26\u53f7\uff0c\u5b83\u8868\u793a\u4e0d\u4e0e\u8be5\u9879\u5339\u914d\u3002

\n\u793a\u4f8b\uff1a
\n$ iptables -A INPUT -p TCP, UDP

\n$ iptables -A INPUT -p ! ICMP <\/p>\n

\u5728\u4e0a\u8ff0\u793a\u4f8b\u4e2d\uff0c\u8fd9\u4e24\u6761\u547d\u4ee4\u90fd\u6267\u884c\u540c\u4e00\u4efb\u52a1 \u2014 \u5b83\u4eec\u6307\u5b9a\u6240\u6709 TCP \u548c UDP \u4fe1\u606f\u5305\u90fd\u5c06\u4e0e\u8be5\u89c4\u5219\u5339\u914d\u3002\u901a\u8fc7\u6307\u5b9a ! ICMP\uff0c\u6211\u4eec\u6253\u7b97\u5141\u8bb8\u6240\u6709\u5176\u5b83\u534f\u8bae\uff08\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\u662f TCP \u548c UDP\uff09\uff0c\u800c\u5c06 ICMP \u6392\u9664\u5728\u5916\u3002 <\/p>\n

\n-s \u6216 –source\uff1a\u8be5\u6e90\u5339\u914d\u7528\u4e8e\u6839\u636e\u4fe1\u606f\u5305\u7684\u6e90 IP \u5730\u5740\u6765\u4e0e\u5b83\u4eec\u5339\u914d\u3002\u8be5\u5339\u914d\u8fd8\u5141\u8bb8\u5bf9\u67d0\u4e00\u8303\u56f4\u5185\u7684 IP \u5730\u5740\u8fdb\u884c\u5339\u914d\uff0c\u53ef\u4ee5\u4f7f\u7528 ! \u7b26\u53f7\uff0c\u8868\u793a\u4e0d\u4e0e\u8be5\u9879\u5339\u914d\u3002\u7f3a\u7701\u6e90\u5339\u914d\u4e0e\u6240\u6709 IP \u5730\u5740\u5339\u914d\u3002

\n\u793a\u4f8b\uff1a
\n$ iptables -A OUTPUT -s 192.168.1.1

\n$ iptables -A OUTPUT -s 192.168.0.0\/24

\n$ iptables -A OUTPUT -s ! 203.16.1.89 <\/p>\n

\u7b2c\u4e8c\u6761\u547d\u4ee4\u6307\u5b9a\u8be5\u89c4\u5219\u4e0e\u6240\u6709\u6765\u81ea 192.168.0.0 \u5230 192.168.0.24 \u7684 IP \u5730\u5740\u8303\u56f4\u7684\u4fe1\u606f\u5305\u5339\u914d\u3002\u7b2c\u4e09\u6761\u547d\u4ee4\u6307\u5b9a\u8be5\u89c4\u5219\u5c06\u4e0e\u9664\u6765\u81ea\u6e90\u5730\u5740 203.16.1.89 \u5916\u7684\u4efb\u4f55\u4fe1\u606f\u5305\u5339\u914d\u3002 <\/p>\n

\n-d \u6216 –destination\uff1a\u8be5\u76ee\u7684\u5730\u5339\u914d\u7528\u4e8e\u6839\u636e\u4fe1\u606f\u5305\u7684\u76ee\u7684\u5730 IP \u5730\u5740\u6765\u4e0e\u5b83\u4eec\u5339\u914d\u3002\u8be5\u5339\u914d\u8fd8\u5141\u8bb8\u5bf9\u67d0\u4e00\u8303\u56f4\u5185 IP \u5730\u5740\u8fdb\u884c\u5339\u914d\uff0c\u53ef\u4ee5\u4f7f\u7528 ! \u7b26\u53f7\uff0c\u8868\u793a\u4e0d\u4e0e\u8be5\u9879\u5339\u914d\u3002

\n\u793a\u4f8b\uff1a
\n$ iptables -A INPUT -d 192.168.1.1

\n$ iptables -A INPUT -d 192.168.0.0\/24

\n$ iptables -A OUTPUT -d ! 203.16.1.89 <\/p>\n

\u76ee\u6807\uff08target\uff09
\n\u6211\u4eec\u5df2\u7ecf\u77e5\u9053\uff0c\u76ee\u6807\u662f\u7531\u89c4\u5219\u6307\u5b9a\u7684\u64cd\u4f5c\uff0c\u5bf9\u4e0e\u90a3\u4e9b\u89c4\u5219\u5339\u914d\u7684\u4fe1\u606f\u5305\u6267\u884c\u8fd9\u4e9b\u64cd\u4f5c\u3002\u9664\u4e86\u5141\u8bb8\u7528\u6237\u5b9a\u4e49\u7684\u76ee\u6807\u4e4b\u5916\uff0c\u8fd8\u6709\u8bb8\u591a\u53ef\u7528\u7684\u76ee\u6807\u9009\u9879\u3002\u4e0b\u9762\u662f\u5e38\u7528\u7684\u4e00\u4e9b\u76ee\u6807\u53ca\u5176\u793a\u4f8b\u548c\u8bf4\u660e\uff1a<\/p>\n

ACCEPT\uff1a\u5f53\u4fe1\u606f\u5305\u4e0e\u5177\u6709 ACCEPT \u76ee\u6807\u7684\u89c4\u5219\u5b8c\u5168\u5339\u914d\u65f6\uff0c\u4f1a\u88ab\u63a5\u53d7\uff08\u5141\u8bb8\u5b83\u524d\u5f80\u76ee\u7684\u5730\uff09\uff0c\u5e76\u4e14\u5b83\u5c06\u505c\u6b62\u904d\u5386\u94fe\uff08\u867d\u7136\u8be5\u4fe1\u606f\u5305\u53ef\u80fd\u904d\u5386\u53e6\u4e00\u4e2a\u8868\u4e2d\u7684\u5176\u5b83\u94fe\uff0c\u5e76\u4e14\u6709\u53ef\u80fd\u5728\u90a3\u91cc\u88ab\u4e22\u5f03\uff09\u3002\u8be5\u76ee\u6807\u88ab\u6307\u5b9a\u4e3a -j ACCEPT\u3002 <\/p>\n

\nDROP\uff1a\u5f53\u4fe1\u606f\u5305\u4e0e\u5177\u6709 DROP \u76ee\u6807\u7684\u89c4\u5219\u5b8c\u5168\u5339\u914d\u65f6\uff0c\u4f1a\u963b\u585e\u8be5\u4fe1\u606f\u5305\uff0c\u5e76\u4e14\u4e0d\u5bf9\u5b83\u505a\u8fdb\u4e00\u6b65\u5904\u7406\u3002\u8be5\u76ee\u6807\u88ab\u6307\u5b9a\u4e3a -j DROP\u3002 <\/p>\n

\nREJECT\uff1a\u8be5\u76ee\u6807\u7684\u5de5\u4f5c\u65b9\u5f0f\u4e0e DROP \u76ee\u6807\u76f8\u540c\uff0c\u4f46\u5b83\u6bd4 DROP \u597d\u3002\u548c DROP \u4e0d\u540c\uff0cREJECT \u4e0d\u4f1a\u5728\u670d\u52a1\u5668\u548c\u5ba2\u6237\u673a\u4e0a\u7559\u4e0b\u6b7b\u5957\u63a5\u5b57\u3002\u53e6\u5916\uff0cREJECT \u5c06\u9519\u8bef\u6d88\u606f\u53d1\u56de\u7ed9\u4fe1\u606f\u5305\u7684\u53d1\u9001\u65b9\u3002\u8be5\u76ee\u6807\u88ab\u6307\u5b9a\u4e3a -j REJECT\u3002

\n\u793a\u4f8b\uff1a
\n$ iptables -A FORWARD -p TCP –dport 22 -j REJECT <\/p>\n

RETURN\uff1a\u5728\u89c4\u5219\u4e2d\u8bbe\u7f6e\u7684 RETURN \u76ee\u6807\u8ba9\u4e0e\u8be5\u89c4\u5219\u5339\u914d\u7684\u4fe1\u606f\u5305\u505c\u6b62\u904d\u5386\u5305\u542b\u8be5\u89c4\u5219\u7684\u94fe\u3002\u5982\u679c\u94fe\u662f\u5982 INPUT \u4e4b\u7c7b\u7684\u4e3b\u94fe\uff0c\u5219\u4f7f\u7528\u8be5\u94fe\u7684\u7f3a\u7701\u7b56\u7565\u5904\u7406\u4fe1\u606f\u5305\u3002\u5b83\u88ab\u6307\u5b9a\u4e3a -jump RETURN\u3002\u793a\u4f8b\uff1a

\n$ iptables -A FORWARD -d 203.16.1.89 -jump RETURN <\/p>\n

\u8fd8\u6709\u8bb8\u591a\u7528\u4e8e\u5efa\u7acb\u9ad8\u7ea7\u89c4\u5219\u7684\u5176\u5b83\u76ee\u6807\uff0c\u5982 LOG\u3001REDIRECT\u3001MARK\u3001MIRROR \u548c MASQUERADE \u7b49\u3002<\/p>\n

\u4fdd\u5b58\u89c4\u5219
\n\u73b0\u5728\uff0c\u60a8\u5df2\u7ecf\u5b66\u4e60\u4e86\u5982\u4f55\u5efa\u7acb\u57fa\u672c\u7684\u89c4\u5219\u548c\u94fe\u4ee5\u53ca\u5982\u4f55\u4ece\u4fe1\u606f\u5305\u8fc7\u6ee4\u8868\u4e2d\u6dfb\u52a0\u6216\u5220\u9664\u5b83\u4eec\u3002\u4f46\u662f\uff0c\u60a8\u5e94\u8be5\u8bb0\u4f4f\uff1a\u7528\u4e0a\u8ff0\u65b9\u6cd5\u6240\u5efa\u7acb\u7684\u89c4\u5219\u4f1a\u88ab\u4fdd\u5b58\u5230\u5185\u6838\u4e2d\uff0c\u5f53\u91cd\u65b0\u5f15\u5bfc\u7cfb\u7edf\u65f6\uff0c\u4f1a\u4e22\u5931\u8fd9\u4e9b\u89c4\u5219\u3002\u6240\u4ee5\uff0c\u5982\u679c\u60a8\u5c06\u6ca1\u6709\u9519\u8bef\u7684\u4e14\u6709\u6548\u7684\u89c4\u5219\u96c6\u6dfb\u52a0\u5230\u4fe1\u606f\u5305\u8fc7\u6ee4\u8868\uff0c\u540c\u65f6\u5e0c\u671b\u5728\u91cd\u65b0\u5f15\u5bfc\u4e4b\u540e\u518d\u6b21\u4f7f\u7528\u8fd9\u4e9b\u89c4\u5219\uff0c\u90a3\u4e48\u5fc5\u987b\u5c06\u8be5\u89c4\u5219\u96c6\u4fdd\u5b58\u5728\u6587\u4ef6\u4e2d\u3002\u53ef\u4ee5\u4f7f\u7528 iptables-save \u547d\u4ee4\u6765\u505a\u5230\u8fd9\u4e00\u70b9\uff1a <\/p>\n

$ iptables-save > iptables-script <\/p>\n

\n\u73b0\u5728\uff0c\u4fe1\u606f\u5305\u8fc7\u6ee4\u8868\u4e2d\u7684\u6240\u6709\u89c4\u5219\u90fd\u88ab\u4fdd\u5b58\u5728\u6587\u4ef6 iptables-script \u4e2d\u3002\u65e0\u8bba\u4f55\u65f6\u518d\u6b21\u5f15\u5bfc\u7cfb\u7edf\uff0c\u90fd\u53ef\u4ee5\u4f7f\u7528 iptables-restore \u547d\u4ee4\u5c06\u89c4\u5219\u96c6\u4ece\u8be5\u811a\u672c\u6587\u4ef6\u6062\u590d\u5230\u4fe1\u606f\u5305\u8fc7\u6ee4\u8868\uff0c\u5982\u4e0b\u6240\u793a\uff1a <\/p>\n

$ iptables-restore iptables-script <\/p>\n

\n\u5982\u679c\u60a8\u613f\u610f\u5728\u6bcf\u6b21\u5f15\u5bfc\u7cfb\u7edf\u65f6\u81ea\u52a8\u6062\u590d\u8be5\u89c4\u5219\u96c6\uff0c\u5219\u53ef\u4ee5\u5c06\u4e0a\u9762\u6307\u5b9a\u7684\u8fd9\u6761\u547d\u4ee4\u653e\u5230\u4efb\u4f55\u4e00\u4e2a\u521d\u59cb\u5316 shell \u811a\u672c\u4e2d\u3002<\/p>\n

\n\u56db\u3001\u51c6\u5907\u5de5\u4f5c<\/p>\n

1. \u7f16\u8bd1\u5185\u6838\uff0c\u7f16\u8bd1\u65f6\u9009\u4e2d\u4ee5\u4e0b\u9009\u9879\uff0c\u5177\u4f53\u53ef\u53c2\u770b\u201c\u7528iptales\u5b9e\u73b0\u5305\u8fc7\u8651\u578b\u9632\u706b\u5899\u201d\u4e00\u6587\uff1a<\/p>\n

Full NAT

\n MASQUERADE target support

\n REDIRECT target support <\/p>\n

2. \u8981\u4f7f\u7528NAT\u8868\u65f6\uff0c\u5fc5\u987b\u9996\u5148\u8f7d\u5165\u76f8\u5173\u6a21\u5757\uff1a<\/p>\n

modprobe ip_tables

\nmodprobe ip_nat_ftp

\niptable_nat \u6a21\u5757\u4f1a\u5728\u8fd0\u884c\u65f6\u81ea\u52a8\u8f7d\u5165\u3002\n<\/p>\n

\u5bf9RedHat Linux 8.0\u4ee5\u4e0a\u7684\u7248\u672c\uff0c\u4ee5\u4e0a\u5de5\u4f5c\u5df2\u7ecf\u5b8c\u6210\uff0c\u4e0d\u9700\u8981\u81ea\u5df1\u505a\u4e86\u3002<\/p>\n

\n\u4e94\u3001\u4f7f\u7528\u5b9e\u4f8b<\/p>\n

1. \u6e90NAT(SNAT)<\/p>\n

\u6bd4\u5982\uff0c\u66f4\u6539\u6240\u6709\u6765\u81ea192.168.1.0\/24\u7684\u6570\u636e\u5305\u7684\u6e90ip\u5730\u5740\u4e3a202.102.2.1\uff1a<\/p>\n

iptables -t nat -A POSTROUTING -s 192.168.1.0\/24 -o eth0 -j SNAT –to
\n 202.102.2.1<\/p>\n

\u8fd9\u91cc\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u7cfb\u7edf\u5728\u8def\u7531\u53ca\u8fc7\u8651\u7b49\u5904\u7406\u76f4\u5230\u6570\u636e\u5305\u8981\u88ab\u9001\u51fa\u65f6\u624d\u8fdb\u884cSNAT\u3002<\/p>\n

\u6709\u4e00\u79cdSNAT\u7684\u7279\u6b8a\u60c5\u51b5\u662fip\u6b3a\u9a97\uff0c\u4e5f\u5c31\u662f\u6240\u8c13\u7684Masquerading\uff0c\u901a\u5e38\u5efa\u8bae\u5728\u4f7f\u7528\u62e8\u53f7\u4e0a\u7f51\u7684\u65f6\u5019\u4f7f\u7528\uff0c\u6216\u8005\u8bf4\u5728\u5408\u6cd5ip\u5730\u5740\u4e0d\u56fa\u5b9a\u7684\u60c5\u51b5\u4e0b\u4f7f\u7528\u3002\u6bd4\u5982<\/p>\n

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

\u53ef\u4ee5\u770b\u51fa\uff0c\u8fd9\u65f6\u5019\u6211\u4eec\u6ca1\u6709\u5fc5\u8981\u663e\u5f0f\u7684\u6307\u5b9a\u6e90ip\u5730\u5740\u7b49\u4fe1\u606f\u3002<\/p>\n

2. \u76ee\u7684NAT(DNAT)<\/p>\n

\u6bd4\u5982\uff0c\u66f4\u6539\u6765\u81ea192.168.1\/24\u7684\u6570\u636e\u5305\u7684\u76ee\u7684ip\u5730\u5740\u4e3a202.102.2.1\uff1a<\/p>\n

iptables -t nat -A PREROUTING -s 192.168.1\/24 -i eth1 -j DNAT –to 202.102.2.1 <\/p>\n

\u8fd9\u91cc\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u7cfb\u7edf\u662f\u5148\u8fdb\u884cDNAT\uff0c\u7136\u540e\u624d\u8fdb\u884c\u8def\u7531\u53ca\u8fc7\u8651\u7b49\u64cd\u4f5c\u3002<\/p>\n

\u6709\u4e00\u79cdDNAT\u7684\u7279\u6b8a\u60c5\u51b5\u662f\u91cd\u5b9a\u5411\uff0c\u4e5f\u5c31\u662f\u6240\u8c13\u7684Redirection\uff0c\u8fd9\u65f6\u5019\u5c31\u76f8\u5f53\u4e8e\u5c06\u7b26\u5408\u6761\u4ef6\u7684\u6570\u636e\u5305\u7684\u76ee\u7684ip\u5730\u5740\u6539\u4e3a\u6570\u636e\u5305\u8fdb\u5165\u7cfb\u7edf\u65f6\u7684\u7f51\u7edc\u63a5\u53e3\u7684ip\u5730\u5740\u3002\u901a\u5e38\u662f\u5728\u4e0esquid\u914d\u7f6e\u5f62\u6210\u900f\u660e\u4ee3\u7406\u65f6\u4f7f\u7528\uff0c\u5047\u8bbesquid\u7684\u76d1\u542c\u7aef\u53e3\u662f3128\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0b\u8bed\u53e5\u6765\u5c06\u6765\u81ea192.168.1.0\/24\uff0c\u76ee\u7684\u7aef\u53e3\u4e3a80\u7684\u6570\u636e\u5305\u91cd\u5b9a\u5411\u5230squid\u76d1\u542c
\n\u7aef\u53e3\uff1a<\/p>\n

iptables -t nat -A PREROUTING -i eth1 -p tcp -s 192.168.1.0\/24 –dport 80

\n-j REDIRECT –to-port 3128<\/p>\n

\u516d\u3001\u7efc\u5408\u4f8b\u5b50 <\/p>\n

1. \u4f7f\u7528\u62e8\u53f7\u5e26\u52a8\u5c40\u57df\u7f51\u4e0a\u7f51<\/p>\n

\u5c0f\u578b\u4f01\u4e1a\u3001\u7f51\u5427\u7b49\u591a\u4f7f\u7528\u62e8\u53f7\u7f51\u7edc\u4e0a\u7f51\uff0c\u901a\u5e38\u53ef\u80fd\u4f7f\u7528\u4ee3\u7406\uff0c\u4f46\u662f\u8003\u8651\u5230\u6210\u672c\u3001\u5bf9\u534f\u8bae\u7684\u652f\u6301\u7b49\u56e0\u7d20\uff0c\u5efa\u8bae\u4f7f\u7528ip\u6b3a\u9a97\u65b9\u5f0f\u5e26\u52a8\u533a\u57df\u7f51\u4e0a\u7f51\u3002<\/p>\n

\u6210\u529f\u5347\u7ea7\u5185\u6838\u540e\u5b89\u88c5iptables\uff0c\u7136\u540e\u6267\u884c\u4ee5\u4e0b\u811a\u672c\uff1a<\/p>\n

#\u8f7d\u5165\u76f8\u5173\u6a21\u5757
\nmodprobe ip_tables

\nmodprobe ip_nat_ftp\n<\/p>\n

#\u542f\u52a8\u8def\u7531\u8f6c\u53d1:(*\u6bcf\u6b21\u5f00\u673a\u90fd\u8981\u542f\u52a8*)\n<\/p>\n

echo “1” > \/proc\/sys\/net\/ipv4\/ip_forward\n<\/p>\n

\n #\u542f\u52a8ip\u4f2a\u88c5:\/etc\/sysconfig\/network\u4e2d\u7684
\n NETWORKING=yes
\n HOSTNAME=scisoftserver(*\u4e3b\u673a\u540d*)
\n #\u4ee5\u4e0b\u4e09\u9879\u9700\u624b\u5de5\u6539\u52a8\u6216\u6dfb\u52a0
\n GATEWAY=255.255.255.0
\n #\u5f00\u673a\u7f51\u7edc\u914d\u7f6e\u751f\u6548
\n ONBOOT=YES
\n #\u670d\u52a1\u5668\u652f\u6301\u8def\u7531\u8f6c\u53d1
\n FORWARD_IPV4=yes<\/p>\n

#\u8fdb\u884cip\u4f2a\u88c5
\niptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE<\/p>\n

2. ip\u6620\u5c04<\/p>\n

\u5047\u8bbe\u6709\u4e00\u5bb6ISP\u63d0\u4f9b\u56ed\u533aInternet\u63a5\u5165\u670d\u52a1\uff0c\u4e3a\u4e86\u65b9\u4fbf\u7ba1\u7406\uff0c\u8be5ISP\u5206\u914d\u7ed9\u56ed\u533a\u7528\u6237\u7684IP\u5730\u5740\u90fd\u662f\u4f2aIP\uff0c\u4f46\u662f\u90e8\u5206\u7528\u6237\u8981\u6c42\u5efa\u7acb\u81ea\u5df1\u7684WWW\u670d\u52a1\u5668\u5bf9\u5916\u53d1\u5e03\u4fe1\u606f\u3002\u6211\u4eec\u53ef\u4ee5\u518d\u9632\u706b\u5899\u7684\u5916\u90e8\u7f51\u5361\u4e0a\u7ed1\u5b9a\u591a\u4e2a\u5408\u6cd5IP\u5730\u5740\uff0c\u7136\u540e\u901a\u8fc7ip\u6620\u5c04\u4f7f\u53d1\u7ed9\u5176\u4e2d\u67d0\u4e00\u4e2aIP\u5730\u5740\u7684\u5305\u8f6c\u53d1\u81f3\u5185\u90e8\u67d0\u4e00\u7528\u6237\u7684WWW\u670d\u52a1\u5668\u4e0a\uff0c\u7136\u540e\u518d\u5c06\u8be5\u5185\u90e8WWW\u670d\u52a1\u5668\u54cd\u5e94\u5305\u4f2a\u88c5\u6210\u8be5\u5408\u6cd5IP\u53d1\u51fa\u7684\u5305\u3002<\/p>\n

\u6211\u4eec\u5047\u8bbe\u4ee5\u4e0b\u60c5\u666f\uff1a<\/p>\n

\u8be5ISP\u5206\u914d\u7ed9A\u5355\u4f4dwww\u670d\u52a1\u5668\u7684ip\u4e3a\uff1a
\n\u4f2aip\uff1a192.168.1.100
\n\u771f\u5b9eip\uff1a202.110.123.100<\/p>\n

\u8be5ISP\u5206\u914d\u7ed9B\u5355\u4f4dwww\u670d\u52a1\u5668\u7684ip\u4e3a\uff1a
\n\u4f2aip\uff1a192.168.1.200
\n\u771f\u5b9eip\uff1a202.110.123.200<\/p>\n

linux\u9632\u706b\u5899\u7684ip\u5730\u5740\u5206\u522b\u4e3a\uff1a
\n\u5185\u7f51\u63a5\u53e3eth1\uff1a192.168.1.1
\n\u5916\u7f51\u63a5\u53e3eth0\uff1a202.110.123.1<\/p>\n

\u7136\u540e\u6211\u4eec\u5c06\u5206\u914d\u7ed9A\u3001B\u5355\u4f4d\u7684\u771f\u5b9eip\u7ed1\u5b9a\u5230\u9632\u706b\u5899\u7684\u5916\u7f51\u63a5\u53e3\uff0c\u4ee5root\u6743\u9650\u6267\u884c\u4ee5\u4e0b\u547d\u4ee4\uff1a<\/p>\n

ifconfig eth0 add 202.110.123.100 netmask 255.255.255.0

\nifconfig eth0 add 202.110.123.200 netmask 255.255.255.0<\/p>\n

\u6210\u529f\u5347\u7ea7\u5185\u6838\u540e\u5b89\u88c5iptables\uff0c\u7136\u540e\u6267\u884c\u4ee5\u4e0b\u811a\u672c\uff1a<\/p>\n

#\u8f7d\u5165\u76f8\u5173\u6a21\u5757
\nmodprobe ip_tables

\nmodprobe ip_nat_ftp<\/p>\n

\u9996\u5148\uff0c\u5bf9\u9632\u706b\u5899\u63a5\u6536\u5230\u7684\u76ee\u7684ip\u4e3a202.110.123.100\u548c202.110.123.200\u7684\u6240\u6709\u6570\u636e\u5305\u8fdb\u884c\u76ee\u7684NAT(DNAT):<\/p>\n

iptables -t nat -A PREROUTING -i eth0 -d 202.110.123.100 -j DNAT –to 192.168.1.100

\niptables -t nat -A PREROUTING -i eth0 -d 202.110.123.200 -j DNAT –to 192.168.1.200<\/p>\n

\u5176\u6b21\uff0c\u5bf9\u9632\u706b\u5899\u63a5\u6536\u5230\u7684\u6e90ip\u5730\u5740\u4e3a192.168.1.100\u548c192.168.1.200\u7684\u6570\u636e\u5305\u8fdb\u884c\u6e90NAT(SNAT):<\/p>\n

iptables -t nat -A POSTROUTING -o eth0 -s 192.168.1.100 -j SNAT –to 202.110.123.100

\niptables -t nat -A POSTROUTING -o eth0 -s 192.168.1.200 -j SNAT –to 202.110.123.200<\/p>\n

\u8fd9\u6837\uff0c\u6240\u6709\u76ee\u7684ip\u4e3a202.110.123.100\u548c202.110.123.200\u7684\u6570\u636e\u5305\u90fd\u5c06\u5206\u522b\u88ab\u8f6c\u53d1\u7ed9192.168.1.100\u548c192.168.1.200\uff1b\u800c\u6240\u6709\u6765\u81ea192.168.1.100\u548c192.168.1.200\u7684\u6570\u636e\u5305\u90fd\u5c06\u5206\u522b\u88ab\u4f2a\u88c5\u6210\u7531202.110.123.100\u548c202.110.123.200\uff0c\u4ece\u800c\u4e5f\u5c31\u5b9e\u73b0\u4e86ip\u6620\u5c04\u3002\n<\/p>\n

\u4e03\u3001\u5b89\u88c5ipp2p\u9650\u5236p2p\u8f6f\u4ef6\n<\/p>\n

\u4e0b\u8f7dipp2p-0.8.0.tar.gz\n<\/p>\n

\u4fee\u6539 Makefile \u6587\u4ef6\u4e2d “IPTABLES_SRC = \/usr\/src\/iptables-1.2.9”
\n \u4e3aiptables\u6e90\u6587\u4ef6\u76ee\u5f55\n<\/p>\n

make\n<\/p>\n

\u590d\u5236 libipt_ipp2p.so \u5230 iptables lib \u76ee\u5f55 (\/lib\/iptables\/)
\n \u590d\u5236 ipt_ipp2p.o \u6216 ipt_ipp2p.ko \u5230 kernel modules \u76ee\u5f55\n<\/p>\n

depmod -a\n<\/p>\n

\u8fd9\u6837ipp2p\u5c31\u5b89\u88c5\u5b8c\u6210\u4e86\n<\/p>\n

iptables -m ipp2p –help \u67e5\u770b\u4f7f\u7528\u8bf4\u660e\n<\/p>\n

\u516b\u3001\u9650\u5236\u5ba2\u6237\u7ebf\u7a0b\u6570\n<\/p>\n

iptables -I FORWARD -p tcp -s 192.168.0.18 -m connlimit –connlimit-above 100 –connlimit-mask 32 -j REJECT\n<\/p>\n

–connlimit-above \u6307\u5b9a\u7ebf\u7a0b\u6570 –connlimit-mask \u6307\u5b9aIP\u7684mask \u5f5332\u65f6\u5c31\u662f\u5bf9\u5355\u4e2aIP\u9650\u5236\u3002\n<\/p>\n

\u9644\uff1aiptables\u5904\u7406\u6d41\u7a0b\u56fe\n<\/p>\n

“>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

\u4e00\u3001\u6982\u8ff0 1. \u4ec0\u4e48\u662fNAT \u5728\u4f20\u7edf\u7684\u6807\u51c6\u7684TCP\/IP\u901a\u4fe1\u8fc7\u7a0b\u4e2d\uff0c\u6240\u6709\u7684\u8def\u7531\u5668\u4ec5\u4ec5\u662f\u5145\u5f53\u4e00\u4e2a\u4e2d\u95f4\u4eba\u7684\u89d2\u8272\uff0c\u4e5f […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"_links":{"self":[{"href":"http:\/\/www.microwolf.net\/index.php?rest_route=\/wp\/v2\/posts\/161"}],"collection":[{"href":"http:\/\/www.microwolf.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.microwolf.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.microwolf.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.microwolf.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=161"}],"version-history":[{"count":1,"href":"http:\/\/www.microwolf.net\/index.php?rest_route=\/wp\/v2\/posts\/161\/revisions"}],"predecessor-version":[{"id":162,"href":"http:\/\/www.microwolf.net\/index.php?rest_route=\/wp\/v2\/posts\/161\/revisions\/162"}],"wp:attachment":[{"href":"http:\/\/www.microwolf.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=161"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.microwolf.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=161"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.microwolf.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=161"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}