\u8fd9\u91cc\u6211\u4eec\u4e3b\u8981\u662f\u662f\u7b80\u5355\u8bb2\u89e3\u4e00\u4e0bUDP\u5b9e\u73b0NAT\u7684\u7a7f\u900f\uff08\u4fd7\u79f0\u6253\u6d1e\uff09
\n\u5f53\u7136TCP\u4e0e\u4e4b\u76f8\u4f3c\uff0c\u53ef\u4ee5\u4ee5\u6b64\u7c7b\u63a8\u3002<\/p>\n
NAT\u6700\u5f00\u59cb\u51fa\u73b0\u5728\u8def\u7531\u5668\u4e0a\u3002\u8be6\u7ec6\u7684\u5927\u5bb6\u53ef\u4ee5\u5728\u7f51\u4e0a\u67e5\u4e0b\u8d44\u6599
\nNAT\u7684\u5168\u79f0\u662fNetwork Address Translator\u4e2d\u6587\u79f0\u4e4b\u4e3a\u7f51\u7edc\u5730\u5740\u8f6c\u6362
\nNAT\u5206\u4e3a\u4e24\u5927\u7c7b\uff0cNAT\u548cNAPT\uff08Network Address Port Translator\uff09\u8fd9\u4e2a\u4e0d\u7528\u8bf4\u4e86\uff0c\u7aef\u53e3\u5730\u5740\u8f6c\u6362\u3002<\/p>\n
\u7528\u4e8e\u5b9e\u4f8b\uff0c\u7b80\u5355\u7684\u8bf4\uff0c\u5b9e\u73b0P2P\u9700\u8981\u4e00\u4e2a\u4e2d\u8f6c\u670d\u52a1\u5668\u3002\u4e5f\u5c31\u662f\u9700\u8981\u4e00\u4e2a\u7b2c\u4e09\u65b9\u3002\uff08\u4e00\u4f1a\u513f\u6211\u4eec\u6765\u8bf4\u4e3a\u4ec0\u4e48\u9700\u8981\u4e00\u4e2a\u7b2c\u4e09\u65b9\uff09<\/p>\n
\u4ee5\u7b80\u5355\u7684\u901a\u8fc5\u6765\u8bb2\uff0c\u9996\u5148\u6211\u4eec\u6765\u770b\u4e00\u4e2a\u793a\u4f8b\u56fe\u3002<\/p>\n
A<\u2014\u2014\u2014\u2014\u2014\u2014>B A\u4e0eB\u4e4b\u95f4\u8fdb\u884c\u7684\u901a\u8fc5
\nA\u7684IP\u5730\u5740\u4e3a222.182.100.1
\nB\u7684IP\u5730\u5740\u4e3a222.182.100.2
\n\u5982\u679c\u8fd9\u4e24\u4e2a\u7528\u6237\u90fd\u662f\u91c7\u7528\u7684\u5168\u7403\u552f\u4e00\u7684IP\u5730\u5740\uff0c\u90a3\u4e48\u4ed6\u4eec\u901a\u8fc5\u5f88\u7b80\u5355\uff0c\u4e5f\u4e0d\u9700\u8981\u5b9e\u73b0P2P\u3002
\nA<——————>Nat<——————–>B
\n\u5982\u679c\u5176\u4e2d\u4e00\u65b9\u4e3a\u5185\u7f51\u7528\u6237\uff0c\u53caIP\u5730\u5740\u4e0d\u4e3a\u5168\u7403\u552f\u4e00IP
\n\u5c31\u4f1a\u51fa\u73b0\u901a\u8fc7\u8def\u7531\u5668\u8fdb\u884c\u901a\u8fc5\u3002
\n\u90a3\u4e48\u5728\u7ecf\u8fc7\u8def\u7531\u5668\u7684\u65f6\u5019\uff0c\u8def\u7531\u5668\u4f1a\u51fa\u73b0\u6620\u5c04IP\u5730\u5740\u4e0e\u7aef\u53e3\u7684\u60c5\u51b5\u3002
\n\u5982\uff1aA\u4e3a\u5185\u7f51\u7528\u6237\u3002B\u4e3a\u5916\u7f51\u7528\u6237\u3002\u5219B\u7684IP\u5730\u56fe\u4e3a\u5168\u7403\u552f\u4e00IP\u5730\u5740\u3002\u53ef\u4ee5\u76f4\u63a5\u901a\u8fc5\u3002
\nA\u7684IP\u5730\u5740\u4e3a\uff1a192.168.1.100 \u7aef\u53e3\u4e3a1025
\n\u7ecf\u8fc7\u8def\u7531\u5668\u5411B\u8fdb\u884c\u901a\u8fc5\uff0c\u8def\u7531\u5668\u5c06\u4f1a\u4ea7\u751f\u4e00\u4e2a\u4e00\u5206\u949f\u5230\u51e0\u5c0f\u65f6\u4e0d\u5b9a\u7684\u4e00\u4e2aSession\uff0c\u8fd9\u4e2aSession\u6620\u5c04\u4e86\u5185\u7f51A\u7684IP\u5730\u5740\u53ca\u5176\u63a5\u6536\u4fe1\u606f\u7684\u7aef\u53e3\u3002
\n\u90a3\u4e48\u8def\u7531\u5411B\u53d1\u9001\u4fe1\u606f\u7684\u65f6\u5019\uff0cIP\u5730\u5740\u53ca\u7aef\u53e3\u5c31\u53d8\u6210\u4e86222.182.100.1:3645(\u5047\u8bbe)
\n\u8fd9\u4e2a\u65f6\u5019\u5b9e\u9645\u4e0aA\u5c31\u662f\u5728\u8fdb\u884c\u8def\u7531NAT\u7684\u7a7f\u900f\uff0c
\n\u5982\u679c\u6211\u4eec\u5728B\u5411A\u53d1\u9001\u4fe1\u606f\u7684\u65f6\u5019\u91c7\u7528192.168.1.100:1025\u8fd9\u6837\u7684IP\u548c\u7aef\u53e3\uff0c\u662f\u627e\u4e0d\u5230A\u7684\uff0c\u56e0\u4e3a\u8fd9\u4e2aIP\u4e0d\u662f\u5168\u7403\u552f\u4e00IP\u3002
\n\u90a3\u4e48B\u9700\u8981\u7684\u662f\u5728\u6536\u5230A\u7684\u4fe1\u606f\u7684\u65f6\u5019\uff0c\u83b7\u53d6\u5176IP\u5730\u5740\u548c\u7aef\u53e3\uff0c\u90a3\u4e48\u83b7\u53d6\u5230\u7684\u5c31\u662f222.182.100.1:3645\u8fd9\u4e2a\u8def\u7531\u5668\u7684\u6620\u5c04Session\u5730\u5740\u3002
\nB\u73b0\u5728\u53ea\u9700\u8981\u5411\u8fd9\u4e2a\u6620\u5c04\u5730\u5740\u53d1\u9001\u6d88\u606f\uff0c\u8def\u7531\u5668\u5c31\u4f1a\u81ea\u52a8\u5c06\u6d88\u606f\u53d1\u9001\u5230\u5bf9\u5e94\u7684A\u65b9\u53bb\u3002\u5426\u5219\u8def\u7531\u5668\u5c06\u5f53\u4f5c\u65e0\u7528\u5305\uff0c\u5c06\u8fd9\u4e2a\u6d88\u606f\u4e22\u5f03\u3002
\n\u90a3\u5982\uff0c\u6211\u4eec\u73b0\u5728\u5c31\u5b9e\u73b0\u4e86\u5c40\u57df\u7f51\u5411\u67d0\u5355\u4e2a\u56fa\u5b9a\u5916\u7f51\u673a\u5668\u53d1\u9001\u6d88\u606f\u3002
\n\u5982 \u679c\u518d\u6765\u4e00\u53f0C\u7aef\uff0c\u4e5f\u662f\u5916\u7f51\u7684IP\u3002C\u901a\u8fc7222.182.100.1:3645\u5411A\u53d1\u9001\u6d88\u606f\uff0cA\u662f\u5426\u80fd\u6536\u5230\u5462\uff1f\u7b54\u6848\u662f\u5426\u5b9a\u7684\uff0cA\u4e0d\u80fd\u6536\u5230\u3002\u4e3a\u4ec0\u4e48\uff1f\u56e0\u4e3a\u8def \u7531\u5728\u6620\u5c04A\u7684\u7a7f\u900f\u65f6\u5c31\u8bb0\u5f55\u4e86B\u7684\u5730\u5740\uff0c\u4e5f\u5c31\u662f\u9664\u4e86B\u5411\u8fd9\u4e2a\u6620\u5c04\u70b9\u53d1\u9001\u6d88\u606f\u53ef\u4ee5\u901a\u5411A\uff0c\u5176\u5b83\u7684\u5730\u5740\u662f\u4e0d\u884c\u7684\u3002\u8def\u7531\u5668\u6b64\u65f6\u4f1a\u5c06\u5176\u5f53\u4f5c\u65e0\u7528\u5305\u6d88\u606f\u7ed9\u4e22\u5f03\u6389\u3002
\n\u90a3\u600e\u4e48\u529e\u5462\uff1f\u53ea\u6709A\u518d\u5411C\u53d1\u9001\u4e00\u4e2a\u7a7f\u900f\uff0cC\u624d\u53ef\u4ee5\u5411A\u53d1\u9001\u6d88\u606f\u3002<\/p>\n
\u4ee5\u4e0a\u6211\u4eec\u53ea\u662f\u8bf4\u4e86\u4e00\u70b9\u57fa\u672c\u7684\u7406\u8bba\u3002\u63a5\u4e0b\u6765\u6211\u4eec\u8981\u5b9e\u73b0\u4ec0\u4e48\uff1f\u4e0d\u540c\u5185\u7f51\u901a\u8fc7internet\u7f51\u8fdb\u884c\u901a\u8fc5\u3002
\n\u518d\u6765\uff0c\u6211\u4eec\u4e3e\u4e2a\u56fe\u4f8b<\/p>\n
A<———–>NatA<———->NatB<———->B
\nA\u7684\u5730\u5740\u662f\uff1a192.168.1.100\u7aef\u53e34000
\nB\u7684\u5730\u5740\u662f\uff1a192.168.1.100\u7aef\u53e34000
\n\u5b83\u4eec\u4e24\u4e2a\u90fd\u662f\u5185\u7f51\u7684\u5730\u5740\u3002\u53ca\u5c40\u57df\u7f51\u5185\u90e8\u5730\u5740\u3002\u5e76\u4e0d\u662f\u5168\u7403\u552f\u4e00\u5730\u5740\u3002
\n\u4e24\u4e2a\u8def\u7531\uff1a
\nNatA\u7684\u5730\u5740\u662f\uff1a222.182.100.1
\nNatB\u7684\u5730\u5740\u662f\uff1a222.182.100.2
\n\u8fd9\u4e24\u4e2a\u8def\u7531\u662f\u5916\u7f51\u7684\u5730\u5740\uff0c\u53ca\u5168\u7403\u552f\u4e00\u5730\u5740\u3002<\/p>\n
\u73b0\u5728\u6211\u4eec\u8981\u5b9e\u73b0A\u4e0eB\u7684\u901a\u8fc5\u3002
\n\u56e0\u4e3aA\u4e0eB\u90fd\u4e0d\u662f\u5916\u7f51\u5730\u5740\u3002\u6240\u4ee5A\u4e0d\u53ef\u80fd\u5411192.168.1.100\u53d1\u9001\u6d88\u606f\u3002\u8fd9\u6d88\u606f\u53ea\u4f1a\u5b83\u81ea\u5df1\u6536\u5230\uff0c\u56e0\u4e3a\u8fd9\u4e2aIP\u662f\u5b83\u81ea\u5df1\u7684\u3002\u540c\u6837B\u4e5f\u4e0d\u53ef\u4ee5\u3002
\n\u90a3\u4e48A\u5411NatB\u53d1\u9001\u6d88\u606f\uff0cB\u80fd\u6536\u5230\u5417\uff1f\u7b54\u6848\u662f\u5426\u5b9a\u7684\uff0c\u4e0d\u80fd\u6536\u5230\u3002\u521a\u624d\u6211\u4eec\u63d0\u5230\u8fc7\u3002\u56e0\u4e3a\u8def\u7531\u6ca1\u6709\u6620\u5c04B\u7684\u5730\u5740\u3002A\u5e76\u4e0d\u77e5\u9053\u8fd9\u4e2aSession\u5c31\u8fdeNatB\u4e5f\u4e0d\u77e5\u9053\u8fd9\u4e2aSession\u56e0\u4e3aB\u6ca1\u6709\u5411A\u53d1\u9001\u6d88\u606f\uff0c\u5e76\u4e0d\u4ea7\u751f\u8fd9\u4e2aSession\u3002
\n\u5c31\u7b97B\u548cA\u540c\u65f6\u5411\u53cc\u65b9\u7684\u8def\u7531\u53d1\u9001\u6d88\u606f\uff0c\u4ea7\u751f\u7684Session\uff0cA\u548cB\u4e5f\u5f97\u4e0d\u5230\u3002\u56e0\u4e3a\u5728\u8def\u7531\u4e0a\u5c31\u628a\u8fd9\u4e2a\u6d88\u606f\u5f53\u505a\u4e3a\u65e0\u7528\u5305\u7ed9\u4e22\u5f03\u6389\u4e86\u3002<\/p>\n
\u90a3\u4e48\u8fd9\u6837\u7684\u60c5\u51b5\u6211\u4eec\u8981\u8fdb\u884c\u901a\u8fc5\u600e\u4e48\u529e\u5462\uff1f
\n\u5bf9\uff0c\u5c31\u662f\u521a\u624d\u6211\u4eec\u63d0\u5230\u7684\u7b2c\u4e09\u65b9\u3002\u7b2c\u4e09\u65b9\u662f\u4e2a\u4ec0\u4e48\u65b9\u5462\uff1f
\n\u7b2c\u4e09\u65b9\u5fc5\u987b\u662f\u4e00\u4e2a\u62e5\u6709\u56fa\u5b9a\u5916\u7f51IP\u7684\u670d\u52a1\u65b9\u3002\u53ca\u4e00\u4e2a\u5916\u7f51\u670d\u52a1\u5668\u3002\u5168\u552f\u4e00IP\u5730\u5740\u3002<\/p>\n
\u56fe\u4f8b\uff1a
\n\u5047\u5b9a\u6211\u4eec\u8fd9\u4e2a\u7b2c\u4e09\u65b9\u4e3aC
\nC IP:222.182.100.3\u7aef\u53e34001
\nA<———–>NatA<—————>C<——————–>NatB<————->B
\n \u2191______________________________\u2191 <\/p>\n
\u539f\u7406\u5982\u4e0b
\nA\u901a\u8fc7\u8def\u7531\u5411C\u53d1\u9001\u6d88\u606f\uff0cC\u83b7\u53d6A\u7684\u5728\u8def\u7531\u4e0a\u7684Session\u5730\u5740\uff0c\u6620\u5c04\u7684IP\u548c\u7aef\u53e3
\nB\u540c\u6837\u3002
\n\u8fd9\u65f6\u5019C\u5c31\u6709\u4e86A\u548cB\u7684\u5730\u5740\u3002
\nC\u53ef\u4ee5\u548cA\u3001B\u8fdb\u884c\u901a\u8fc5\uff0c\u4f46\u662fA\u548cB\u8fd8\u4e0d\u884c\u3002
\n\u73b0\u5728C\u9700\u8981\u901a\u77e5A\u65b9B\u7684\u6620\u5c04IP\u548c\u7aef\u53e3\u3002\u4e5f\u8981\u901a\u77e5B\u65b9A\u7684\u6620\u5c04IP\u548c\u7aef\u53e3\u3002
\n\u8fd9\u6837A\u5c31\u6709\u4e86B\u7684\u6620\u5c04\u5730\u5740\uff0cB\u4e5f\u6709\u4e86A\u7684\u3002\u4f46\u662f\u73b0\u5728\u8fd8\u4e0d\u80fd\u8fdb\u884c\u901a\u8fc5\u3002
\n\u56e0\u4e3a\u5728\u8def\u7531\u4e0aA\u548cB\u90fd\u53ea\u6709\u5bf9C\u7684\u7a7f\u900f\u3002\u5e76\u6ca1\u6709\u76f8\u4e92\u4e4b\u524d\u7684\u7a7f\u900f\u3002
\n\u90a3\u4e48A\u8981\u5411B\u53d1\u9001\u6d88\u606f\u600e\u4e48\u529e\u5462\uff1f\u9700\u8981C\u5411B\u53d1\u9001\u4e00\u4e2a\u6d88\u606f\u544a\u8bc9B\u65b9A\u7684\u5730\u5740\u8ba9B\u5411\u8fd9\u4e2a\u5730\u5740\u53d1\u9001\u4e00\u4e2a\u6d88\u606f\uff0c\u5bf9A\u8fdb\u884c\u4e00\u4e2a\u7a7f\u900f\u3002
\n\u8fd9\u6837A\u5c31\u53ef\u4ee5\u5411B\u53d1\u9001\u6d88\u606f\u4e86\u3002\u5728A\u5411B\u53d1\u9001\u6d88\u606f\u7684\u540c\u65f6\uff0cA\u4e5f\u5728\u5411B\u8fdb\u884c\u7a7f\u900f\u3002
\n\u8fd9\u6837\u5c31\u53ef\u4ee5\u5b9e\u73b0\u76f8\u4e92\u7684\u901a\u8fc5\u4e86\u3002\u5982\u679c\u6709\u591a\u4e2a\u7aef\u70b9\uff0c\u4e5f\u5c31\u4ee5\u6b64\u7c7b\u63a8\u4e86\u3002
\n\u5b97\u4e0a\u6240\u8ff0\u5c31\u662fP2P\u7684UDP\u5b9e\u73b0\u539f\u7406\u4e86\u3002TCP\u4e5f\u662f\u4e00\u6837\u7684\u3002\u63d0\u793a\u4e00\u70b9\u3002Session\u5728\u8def\u7531\u4e0a\u662f\u6709\u65f6\u9650\u7684\uff0c\u4e00\u5206\u949f\u5230\u51e0\u5c0f\u65f6\u4e0d\u5b9a\u3002\u4e0d\u540c\u7684\u8def\u7531\u4e0d\u540c\u7684\u65f6\u95f4\uff0c\u4e3a\u4e86\u4fdd\u6301\u8fd9\u4e2aSession\u7684\u5b58\u5728\uff0c\u4f60\u9700\u8981\u5728\u56fa\u5b9a\u65f6\u95f4\u70b9\u8fdb\u884c\u901a\u8fc5\uff0c\u4fdd\u6301\u8fd9\u4e2a\u7a7f\u900f\uff0c\u5426\u5219\u5c31\u5f97\u91cd\u65b0\u7a7f\u900f\u3002<\/p>\n
\u503c\u5f97\u6ce8\u610f\u7684\u4e00\u70b9\u3002
\n\u8def\u7531\u4e0a\u7684\u6620\u5c04\u6709\u4e24\u79cd\u60c5\u51b5
\n\u7b2c\u4e00\u79cd\u60c5\u51b5\u662f\uff1aCone NAT
\n\u7b2c\u4e8c\u79cd\u60c5\u51b5\u662f\uff1aSymmetric NAT
\n\u6211\u4eec\u4ee5\u4e0a\u7684\u5b9e\u73b0\u662f\u4ee5Cone Nat\u4e3a\u57fa\u7840\u7684\u3002\u4e3a\u4ec0\u4e48\u5462\uff1f\u56e0\u4e3aCone Nat\u5728\u6620\u5c04\u7684\u65f6\u5019\u7aef\u53e3\u662f\u4e0d\u53d8\u7684\u3002\u65e0\u8bba\u4f60\u5185\u7f51\u6709\u591a\u5c11\u53f0\u673a\u5668\uff0c\u5411\u5916\u7f51\u53d1\u9001\u6d88\u606f\u5728\u8def\u7531\u4e0a\u6620\u5c04\u7684\u7aef\u53e3\u90fd\u662f\u4e0d\u53d8\u7684\u3002<\/p>\n
\n\t\u800cSymmetric Nat\u5219\u76f8\u53cd\uff0c\u4e00\u4e2a\u6620\u5c04\u4e00\u4e2a\u7aef\u53e3\u3002\u5982\u679c\u78b0\u5230\u8fd9\u79cd\u60c5\u51b5\u53ea\u6709\u795d\u4f60\u597d\u8fd0\u4e86\uff0c\u6700\u597d\u4e0d\u8981\u731c\u3002(\u5341\u6709\u516b\u4e5d\u731c\u4e0d\u5230\u3002\u6240\u4ee5\u4e0d\u63a8\u8350\u731c)\n<\/p>\n
\n\t\n<\/p>\n
\n\t\n<\/p>\n
\n\t\n<\/p>\n
\n\t\u770b\u770b\u4e0b\u9762\u7684\u60c5\u51b5\uff1a<\/p>\n
Server S1 Server S2
\n 18.181.0.31:1235 138.76.29.7:1235
\n | |
\n | |
\n +———————-+———————-+
\n |
\n ^ Session 1 (A-S1) ^ | ^ Session 2 (A-S2) ^
\n | 18.181.0.31:1235 | | | 138.76.29.7:1235 |
\n v 155.99.25.11:62000 v | v 155.99.25.11:62000 v
\n |
\n Cone NAT
\n 155.99.25.11
\n |
\n ^ Session 1 (A-S1) ^ | ^ Session 2 (A-S2) ^
\n | 18.181.0.31:1235 | | | 138.76.29.7:1235 |
\n v 10.0.0.1:1234 v | v 10.0.0.1:1234 v
\n |
\n Client A
\n 10.0.0.1:1234<\/p>\n
<\/p>\n
\u63a5\u4e0a\u9762\u7684\u4f8b\u5b50\uff0c\u5982\u679cClient A\u7684\u539f\u6765\u90a3\u4e2aSocket(\u7ed1\u5b9a\u4e861234\u7aef\u53e3\u7684\u90a3\u4e2aUDP Socket)\u53c8\u63a5\u7740\u5411\u53e6\u5916\u4e00\u4e2aServer S2\u53d1\u9001\u4e86\u4e00\u4e2aUDP\u5305\uff0c\u90a3\u4e48\u8fd9\u4e2aUDP\u5305\u5728\u901a\u8fc7NAT\u65f6\u4f1a\u600e\u4e48\u6837\u5462\uff1f<\/p>\n
\u8fd9\u65f6\u53ef\u80fd\u4f1a\u6709\u4e24\u79cd\u60c5\u51b5\u53d1\u751f\uff0c\u4e00\u79cd\u662fNAT\u518d\u6b21\u521b\u5efa\u4e00\u4e2aSession\uff0c\u5e76\u4e14\u518d\u6b21\u4e3a\u8fd9\u4e2aSession\u5206\u914d\u4e00\u4e2a\u7aef\u53e3\u53f7\uff08\u6bd4\u5982\uff1a62001\uff09\u3002\u53e6\u5916\u4e00\u79cd\u662fNAT\u518d\u6b21\u521b\u5efa\u4e00\u4e2aSession\uff0c\u4f46\u662f\u4e0d\u4f1a\u65b0\u5206\u914d\u4e00\u4e2a\u7aef\u53e3\u53f7\uff0c\u800c\u662f\u7528\u539f\u6765\u5206\u914d\u7684\u7aef\u53e3\u53f762000\u3002\u524d\u4e00\u79cdNAT\u53eb\u505aSymmetric NAT\uff0c\u540e\u4e00\u79cd\u53eb\u505aCone NAT\u3002\u6211\u4eec\u671f\u671b\u6211\u4eec\u7684NAT\u662f\u7b2c\u4e8c\u79cd\uff0c\u5475\u5475\uff0c\u5982\u679c\u4f60\u7684NAT\u521a\u597d\u662f\u7b2c\u4e00\u79cd\uff0c\u90a3\u4e48\u5f88\u53ef\u80fd\u4f1a\u6709\u5f88\u591aP2P\u8f6f\u4ef6\u5931\u7075\u3002\uff08\u53ef\u4ee5\u5e86\u5e78\u7684\u662f\uff0c\u73b0\u5728\u7edd\u5927\u591a\u6570\u7684NAT\u5c5e\u4e8e\u540e\u8005\uff0c\u5373Cone NAT\uff09<\/p>\n
<\/p>\n
\u597d\u4e86\uff0c\u6211\u4eec\u770b\u5230\uff0c\u901a\u8fc7NAT,\u5b50\u7f51\u5185\u7684\u8ba1\u7b97\u673a\u5411\u5916\u8fde\u7ed3\u662f\u5f88\u5bb9\u6613\u7684\uff08NAT\u76f8\u5f53\u4e8e\u900f\u660e\u7684\uff0c\u5b50\u7f51\u5185\u7684\u548c\u5916\u7f51\u7684\u8ba1\u7b97\u673a\u4e0d\u7528\u77e5\u9053NAT\u7684\u60c5\u51b5\uff09\u3002<\/p>\n
\u4f46\u662f\u5982\u679c\u5916\u90e8\u7684\u8ba1\u7b97\u673a\u60f3\u8bbf\u95ee\u5b50\u7f51\u5185\u7684\u8ba1\u7b97\u673a\u5c31\u6bd4\u8f83\u56f0\u96be\u4e86\uff08\u800c\u8fd9\u6b63\u662fP2P\u6240\u9700\u8981\u7684\uff09\u3002<\/p>\n
\u90a3\u4e48\u6211\u4eec\u5982\u679c\u60f3\u4ece\u5916\u90e8\u53d1\u9001\u4e00\u4e2a\u6570\u636e\u62a5\u7ed9\u5185\u7f51\u7684\u8ba1\u7b97\u673a\u6709\u4ec0\u4e48\u529e\u6cd5\u5462\uff1f\u9996\u5148\uff0c\u6211\u4eec\u5fc5\u987b\u5728\u5185\u7f51\u7684NAT\u4e0a\u6253\u4e0a\u4e00\u4e2a\u201c\u6d1e\u201d\uff08\u4e5f\u5c31\u662f\u524d\u9762\u6211\u4eec\u8bf4\u7684\u5728NAT\u4e0a\u5efa\u7acb\u4e00\u4e2aSession\uff09\uff0c\u8fd9\u4e2a\u6d1e\u4e0d\u80fd\u7531\u5916\u90e8\u6765\u6253\uff0c\u53ea\u80fd\u7531\u5185\u7f51\u5185\u7684\u4e3b\u673a\u6765\u6253\u3002\u800c\u4e14\u8fd9\u4e2a\u6d1e\u662f\u6709\u65b9\u5411\u7684\uff0c\u6bd4\u5982\u4ece\u5185\u90e8\u67d0\u53f0\u4e3b\u673a\uff08\u6bd4\u5982\uff1a192.168.0.10\uff09\u5411\u5916\u90e8\u7684\u67d0\u4e2aIP(\u6bd4\u5982\uff1a219.237.60.1)\u53d1\u9001\u4e00\u4e2aUDP\u5305\uff0c\u90a3\u4e48\u5c31\u5728\u8fd9\u4e2a\u5185\u7f51\u7684NAT\u8bbe\u5907\u4e0a\u6253\u4e86\u4e00\u4e2a\u65b9\u5411\u4e3a219.237.60.1\u7684\u201c\u6d1e\u201d\uff0c\uff08\u8fd9\u5c31\u662f\u79f0\u4e3aUDP Hole Punching\u7684\u6280\u672f\uff09\u4ee5\u540e219.237.60.1\u5c31\u53ef\u4ee5\u901a\u8fc7\u8fd9\u4e2a\u6d1e\u4e0e\u5185\u7f51\u7684192.168.0.10\u8054\u7cfb\u4e86\u3002\uff08\u4f46\u662f\u5176\u4ed6\u7684IP\u4e0d\u80fd\u5229\u7528\u8fd9\u4e2a\u6d1e\uff09\u3002<\/p>\n
<\/p>\n
\u5475\u5475\uff0c\u73b0\u5728\u8be5\u8f6e\u5230\u6211\u4eec\u7684\u6b63\u9898P2P\u4e86\u3002\u6709\u4e86\u4e0a\u9762\u7684\u7406\u8bba\uff0c\u5b9e\u73b0\u4e24\u4e2a\u5185\u7f51\u7684\u4e3b\u673a\u901a\u8baf\u5c31\u5dee\u6700\u540e\u4e00\u6b65\u4e86\uff1a\u90a3\u5c31\u662f\u9e21\u751f\u86cb\u8fd8\u662f\u86cb\u751f\u9e21\u7684\u95ee\u9898\u4e86\uff0c\u4e24\u8fb9\u90fd\u65e0\u6cd5\u4e3b\u52a8\u53d1\u51fa\u8fde\u63a5\u8bf7\u6c42\uff0c\u8c01\u4e5f\u4e0d\u77e5\u9053\u8c01\u7684\u516c\u7f51\u5730\u5740\uff0c\u90a3\u6211\u4eec\u5982\u4f55\u6765\u6253\u8fd9\u4e2a\u6d1e\u5462\uff1f\u6211\u4eec\u9700\u8981\u4e00\u4e2a\u4e2d\u95f4\u4eba\u6765\u8054\u7cfb\u8fd9\u4e24\u4e2a\u5185\u7f51\u4e3b\u673a\u3002<\/p>\n
\u73b0\u5728\u6211\u4eec\u6765\u770b\u770b\u4e00\u4e2aP2P\u8f6f\u4ef6\u7684\u6d41\u7a0b\uff0c\u4ee5\u4e0b\u56fe\u4e3a\u4f8b\uff1a<\/p>\n
Server S \uff08219.237.60.1\uff09
\n |
\n |
\n +———————-+———————-+
\n | |
\n NAT A (\u5916\u7f51IP:202.187.45.3) NAT B (\u5916\u7f51IP:187.34.1.56)
\n | (\u5185\u7f51IP:192.168.0.1) | (\u5185\u7f51IP:192.168.0.1)
\n | |
\nClient A (192.168.0.20:4000) Client B (192.168.0.10:40000)<\/p>\n
<\/p>\n
\n \u9996\u5148\uff0cClient A\u767b\u5f55\u670d\u52a1\u5668\uff0cNAT A\u4e3a\u8fd9\u6b21\u7684Session\u5206\u914d\u4e86\u4e00\u4e2a\u7aef\u53e360000\uff0c\u90a3\u4e48Server S\u6536\u5230\u7684Client A\u7684\u5730\u5740\u662f202.187.45.3:60000\uff0c\u8fd9\u5c31\u662fClient A\u7684\u5916\u7f51\u5730\u5740\u4e86\u3002\u540c\u6837\uff0cClient B\u767b\u5f55Server S\uff0cNAT B\u7ed9\u6b64\u6b21Session\u5206\u914d\u7684\u7aef\u53e3\u662f40000\uff0c\u90a3\u4e48Server S\u6536\u5230\u7684B\u7684\u5730\u5740\u662f187.34.1.56:40000\u3002<\/p>\n
\u6b64\u65f6\uff0cClient A\u4e0eClient B\u90fd\u53ef\u4ee5\u4e0eServer S\u901a\u4fe1\u4e86\u3002\u5982\u679cClient A\u6b64\u65f6\u60f3\u76f4\u63a5\u53d1\u9001\u4fe1\u606f\u7ed9Client B\uff0c\u90a3\u4e48\u4ed6\u53ef\u4ee5\u4eceServer S\u90a3\u513f\u83b7\u5f97B\u7684\u516c\u7f51\u5730\u5740187.34.1.56:40000\uff0c\u662f\u4e0d\u662fClient A\u5411\u8fd9\u4e2a\u5730\u5740\u53d1\u9001\u4fe1\u606fClient B\u5c31\u80fd\u6536\u5230\u4e86\u5462\uff1f\u7b54\u6848\u662f\u4e0d\u884c\uff0c\u56e0\u4e3a\u5982\u679c\u8fd9\u6837\u53d1\u9001\u4fe1\u606f\uff0cNAT B\u4f1a\u5c06\u8fd9\u4e2a\u4fe1\u606f\u4e22\u5f03\uff08\u56e0\u4e3a\u8fd9\u6837\u7684\u4fe1\u606f\u662f\u4e0d\u8bf7\u81ea\u6765\u7684\uff0c\u4e3a\u4e86\u5b89\u5168\uff0c\u5927\u591a\u6570NAT\u90fd\u4f1a\u6267\u884c\u4e22\u5f03\u52a8\u4f5c\uff09\u3002\u73b0\u5728\u6211\u4eec\u9700\u8981\u7684\u662f\u5728NAT B\u4e0a\u6253\u4e00\u4e2a\u65b9\u5411\u4e3a202.187.45.3\uff08\u5373Client A\u7684\u5916\u7f51\u5730\u5740\uff09\u7684\u6d1e\uff0c\u90a3\u4e48Client A\u53d1\u9001\u5230187.34.1.56:40000\u7684\u4fe1\u606f,Client B\u5c31\u80fd\u6536\u5230\u4e86\u3002\u8fd9\u4e2a\u6253\u6d1e\u547d\u4ee4\u7531\u8c01\u6765\u53d1\u5462\uff0c\u5475\u5475\uff0c\u5f53\u7136\u662fServer S\u3002<\/p>\n
\u603b\u7ed3\u4e00\u4e0b\u8fd9\u4e2a\u8fc7\u7a0b\uff1a\u5982\u679cClient A\u60f3\u5411Client B\u53d1\u9001\u4fe1\u606f\uff0c\u90a3\u4e48Client A\u53d1\u9001\u547d\u4ee4\u7ed9Server S\uff0c\u8bf7\u6c42Server S\u547d\u4ee4Client B\u5411Client A\u65b9\u5411\u6253\u6d1e\u3002\u5475\u5475\uff0c\u662f\u4e0d\u662f\u5f88\u7ed5\u53e3\uff0c\u4e0d\u8fc7\u6ca1\u5173\u7cfb\uff0c\u60f3\u4e00\u60f3\u5c31\u5f88\u6e05\u695a\u4e86\uff0c\u4f55\u51b5\u8fd8\u6709\u6e90\u4ee3\u7801\u5462\uff08\u4faf\u8001\u5e08\u8bf4\u8fc7\uff1a\u5728\u6e90\u4ee3\u7801\u9762\u524d\u6ca1\u6709\u79d8\u5bc6 8\uff09\uff09\uff0c\u7136\u540eClient A\u5c31\u53ef\u4ee5\u901a\u8fc7Client B\u7684\u5916\u7f51\u5730\u5740\u4e0eClient B\u901a\u4fe1\u4e86\u3002<\/p>\n
<\/p>\n
\u6ce8\u610f\uff1a\u4ee5\u4e0a\u8fc7\u7a0b\u53ea\u9002\u5408\u4e8eCone NAT\u7684\u60c5\u51b5\uff0c\u5982\u679c\u662fSymmetric NAT\uff0c\u90a3\u4e48\u5f53Client B\u5411Client A\u6253\u6d1e\u7684\u7aef\u53e3\u5df2\u7ecf\u91cd\u65b0\u5206\u914d\u4e86\uff0cClient B\u5c06\u65e0\u6cd5\u77e5\u9053\u8fd9\u4e2a\u7aef\u53e3\uff08\u5982\u679cSymmetric NAT\u7684\u7aef\u53e3\u662f\u987a\u5e8f\u5206\u914d\u7684\uff0c\u90a3\u4e48\u6211\u4eec\u6216\u8bb8\u53ef\u4ee5\u731c\u6d4b\u8fd9\u4e2a\u7aef\u53e3\u53f7\uff0c\u53ef\u662f\u7531\u4e8e\u53ef\u80fd\u5bfc\u81f4\u5931\u8d25\u7684\u56e0\u7d20\u592a\u591a\uff0c\u6211\u4eec\u4e0d\u63a8\u8350\u8fd9\u79cd\u731c\u6d4b\u7aef\u53e3\u7684\u65b9\u6cd5\uff09\u3002\n<\/p>\n
\n\t\n<\/p>\n
\n\tNAT\u7684\u5b8c\u5168\u5206\u6790\u53ca\u5176UDP\u7a7f\u900f\u7684\u5b8c\u5168\u89e3\u51b3\u65b9\u6848
\n
\n\u4e00:\u57fa\u672c\u672f\u8bed
\n\u9632\u706b\u5899
\n\u9632\u706b\u5899\u9650\u5236\u4e86\u79c1\u7f51\u4e0e\u516c\u7f51\u7684\u901a\u4fe1\uff0c\u5b83\u4e3b\u8981\u662f\u5c06\uff08\u9632\u706b\u5899\uff09\u8ba4\u4e3a\u672a\u7ecf\u6388\u6743\u7684\u7684\u5305\u4e22\u5f03\uff0c\u9632\u706b\u5899\u53ea\u662f\u68c0\u9a8c\u5305\u7684\u6570\u636e\uff0c\u5e76\u4e0d\u4fee\u6539\u6570\u636e\u5305\u4e2d\u7684IP\u5730\u5740\u548cTCP\/UDP\u7aef\u53e3\u4fe1\u606f\u3002
\n\u7f51\u7edc\u5730\u5740\u8f6c\u6362\uff08NAT\uff09
\n\u5f53\u6709\u6570\u636e\u5305\u901a\u8fc7\u65f6\uff0c\u7f51\u7edc\u5730\u5740\u8f6c\u6362\u5668\u4e0d\u4ec5\u68c0\u67e5\u5305\u7684\u4fe1\u606f\uff0c\u8fd8\u8981\u5c06\u5305\u5934\u4e2d\u7684IP\u5730\u5740\u548c\u7aef\u53e3\u4fe1\u606f\u8fdb\u884c\u4fee\u6539\u3002\u4ee5\u4f7f\u5f97\u5904\u4e8eNAT\u4e4b\u540e\u7684\u673a\u5668\u5171\u4eab\u51e0\u4e2a\u4ec5\u6709\u7684\u516c\u7f51IP\u5730\u5740\uff08\u901a\u5e38\u662f\u4e00\u4e2a\uff09\u3002\u7f51\u7edc\u5730\u5740\u8f6c\u6362\u5668\u4e3b\u8981\u6709\u4e24\u79cd\u7c7b\u578b.
\nP2P\u5e94\u7528\u7a0b\u5e8f
\nP2P\u5e94\u7528\u7a0b\u5e8f\u662f\u6307\uff0c\u5728\u5df2\u6709\u7684\u4e00\u4e2a\u516c\u5171\u670d\u52a1\u5668\u7684\u57fa\u7840\u4e0a\uff0c\u5e76\u5206\u522b\u5229\u7528\u81ea\u5df1\u7684\u79c1\u6709\u5730\u5740\u6216\u8005\u516c\u6709\u5730\u5740\uff08\u6216\u8005\u4e24\u8005\u517c\u5907\uff09\u6765\u5efa\u7acb\u4e00\u4e2a\u7aef\u5230\u7aef\u7684\u4f1a\u8bdd\u901a\u4fe1\u3002
\nP2P\u9632\u706b\u5899
\nP2P\u9632\u706b\u5899\u662f\u4e00\u4e2a\u63d0\u4f9b\u4e86\u9632\u706b\u5899\u7684\u529f\u80fd\u7684P2P\u4ee3\u7406\uff0c\u4f46\u662f\u4e0d\u8fdb\u884c\u5730\u5740\u8f6c\u6362.
\nP2P-NAT
\nP2P-NAT \u662f\u4e00\u4e2a P2P\u4ee3\u7406,\u63d0\u4f9b\u4e86NAT\u7684\u529f\u80fd,\u4e5f\u63d0\u4f9b\u4e86\u9632\u706b\u5899\u7684\u529f\u80fd,\u4e00\u4e2a\u6700\u7b80\u7684P2P\u4ee3\u7406\u5fc5\u987b\u5177\u6709\u9525\u5f62NAT\u5bf9Udp\u901a\u4fe1\u652f\u6301\u7684\u529f\u80fd,\u5e76\u5141\u8bb8\u5e94\u7528\u7a0b\u5e8f\u5229\u7528Udp\u6253\u6d1e\u6280\u672f\u5efa\u7acb\u5f3a\u5065\u7684P2P\u8fde\u63a5\u3002
\n\u56de\u73af\u8f6c\u6362
\n\u5f53NAT\u7684\u79c1\u7f51\u5185\u90e8\u673a\u5668\u60f3\u901a\u8fc7\u516c\u5171\u5730\u5740\u6765\u8bbf\u95ee\u540c\u4e00\u53f0\u5c40\u57df\u7f51\u5185\u7684\u673a\u5668\u7684\u65f6\uff0cNAT\u8bbe\u5907\u7b49\u4ef7\u4e8e\u505a\u4e86\u4e24\u6b21NAT\u7684\u4e8b\u60c5\uff0c\u5728\u5305\u5230\u8fbe\u76ee\u6807\u673a\u5668\u4e4b\u524d\uff0c\u5148\u5c06\u79c1\u6709\u5730\u5740\u8f6c\u6362\u4e3a\u516c\u7f51\u5730\u5740\uff0c\u7136\u540e\u518d\u5c06\u516c\u7f51\u5730\u5740\u8f6c\u6362\u56de\u79c1\u6709\u5730\u5740\u3002\u6211\u4eec\u628a\u5177\u6709\u4e0a\u53d9\u8f6c\u6362\u529f\u80fd\u7684NAT\u8bbe\u5907\u53eb\u505a\u201c\u56de\u73af\u8f6c\u6362\u201d\u8bbe\u5907\u3002
\n
\n\u4e8c:NAT\u5206\u7c7b
\n\u53ef\u4ee5\u5206\u4e3a\u57fa\u7840NAT\u4e0e\u7f51\u7edc\u5730\u5740\u548c\u7aef\u53e3\u8f6c\u6362(NAPT)\u4e24\u5927\u7c7b
\n(\u4e00):\u57fa\u7840NAT
\n\u57fa\u7840NAT \u5c06\u79c1\u7f51\u4e3b\u673a\u7684\u79c1\u6709IP\u5730\u5740\u8f6c\u6362\u6210\u516c\u7f51IP\u5730\u5740\uff0c\u4f46\u5e76\u4e0d\u5c06TCP\/UDP\u7aef\u53e3\u4fe1\u606f\u8fdb\u884c\u8f6c\u6362\u3002\u57fa\u7840NAT\u4e00\u822c\u7528\u5728\u5f53NAT\u62e5\u6709\u5f88\u591a\u516c\u7f51IP\u5730\u5740\u7684\u65f6\u5019\uff0c\u5b83\u5c06\u516c\u7f51IP\u5730\u5740\u4e0e\u5185\u90e8\u4e3b\u673a\u8fdb\u884c\u7ed1\u5b9a\uff0c\u4f7f\u5f97\u5916\u90e8\u53ef\u4ee5\u7528\u516c\u7f51IP\u5730\u5740\u8bbf\u95ee\u5185\u90e8\u4e3b\u673a\u3002\uff08\u5b9e\u9645\u4e0a\u662f\u53ea\u5c06IP\u8f6c\u6362\uff0c192.168.0.23 <-> 210.42.106.35,\u8fd9\u4e0e\u76f4\u63a5\u8bbe\u7f6eIP\u5730\u5740\u4e3a\u516c\u7f51IP\u8fd8\u662f\u6709\u4e00\u5b9a\u533a\u522b\u7684\uff0c\u7279\u522b\u662f\u5bf9\u4e8e\u4f01\u4e1a\u6765\u8bf4\uff0c\u5916\u90e8\u7684\u4fe1\u606f\u90fd\u8981\u7ecf\u8fc7\u7edf\u4e00\u9632\u706b\u5899\u624d\u80fd\u5230\u8fbe\u5185\u90e8\uff0c\u4f46\u662f\u5185\u90e8\u4e3b\u673a\u53c8\u53ef\u4ee5\u4f7f\u7528\u516c\u7f51IP\uff09
\n(\u4e8c):\u7f51\u7edc\u5730\u5740\u548c\u7aef\u53e3\u8f6c\u6362 \uff08NAPT\uff09
\n\u8fd9\u662f\u6700\u666e\u904d\u7684\u60c5\u51b5\uff0c\u7f51\u7edc\u5730\u5740\/\u7aef\u53e3\u8f6c\u6362\u5668\u68c0\u67e5\u3001\u4fee\u6539\u5305\u7684IP\u5730\u5740\u548cTCP\/UDP\u7aef\u53e3\u4fe1\u606f\uff0c\u8fd9\u6837\uff0c\u66f4\u591a\u7684\u5185\u90e8\u4e3b\u673a\u5c31\u53ef\u4ee5\u540c\u65f6\u4f7f\u7528\u4e00\u4e2a\u516c\u7f51IP\u5730\u5740\u3002
\n\u8bf7\u53c2\u8003[RFC1631]\u548c[RFC2993]\u53ca[RFC2663]\u8fd9\u4e09\u4e2a\u6587\u6863\u4e86\u89e3\u66f4\u591a\u7684NAT\u5206\u7c7b\u548c\u672f\u8bed\u4fe1\u606f\u3002\u53e6\u5916\uff0c\u5173\u4e8eNAPT\u7684\u5206\u7c7b\u548c\u672f\u8bed\uff0c[RFC2663]\u505a\u4e86\u66f4\u591a\u7684\u5b9a\u4e49\u3002\u5f53\u4e00\u4e2a\u5185\u90e8\u7f51\u4e3b\u673a\u901a\u8fc7NAT\u6253\u5f00\u4e00\u4e2a\u201c\u5916\u51fa\u201d\u7684TCP\u6216UDP\u4f1a\u8bdd\u65f6\uff0cNAPT\u5206\u914d\u7ed9\u8fd9\u4e2a\u4f1a\u8bdd\u4e00\u4e2a\u516c\u7f51IP\u548c\u7aef\u53e3\uff0c\u7528\u6765\u63a5\u6536\u5916\u7f51\u7684\u54cd\u5e94\u7684\u6570\u636e\u5305\uff0c\u5e76\u7ecf\u8fc7\u8f6c\u6362\u901a\u77e5\u5185\u90e8\u7f51\u7684\u4e3b\u673a\u3002\u8fd9\u6837\u505a\u7684\u6548\u679c\u662f\uff0cNAPT\u5728 [\u79c1\u6709IP:\u79c1\u6709\u7aef\u53e3] \u548c[\u516c\u7f51IP:\u516c\u7f51\u7aef\u53e3]\u4e4b\u95f4\u5efa\u7acb\u4e86\u4e00\u4e2a\u7aef\u53e3\u7ed1\u5b9a\u3002
\n\u7aef\u53e3\u7ed1\u5b9a\u6307\u5b9a\u4e86NAPT\u5c06\u5728\u8fd9\u4e2a\u4f1a\u8bdd\u7684\u751f\u5b58\u671f\u5185\u8fdb\u884c\u5730\u5740\u8f6c\u6362\u4efb\u52a1\u3002\u8fd9\u4e2d\u95f4\u5b58\u5728\u4e00\u4e2a\u8fd9\u6837\u7684\u95ee\u9898\uff0c\u5982\u679cP2P\u5e94\u7528\u7a0b\u5e8f\u4ece\u5185\u90e8\u7f51\u7edc\u7684\u4e00\u4e2a[\u79c1\u6709IP\u5730\u5740:\u7aef\u53e3]\u5bf9\u540c\u65f6\u53d1\u51fa\u591a\u6761\u4f1a\u8bdd\u7ed9\u4e0d\u540c\u7684\u5916\u7f51\u4e3b\u673a\uff0c\u90a3\u4e48NAT\u4f1a\u600e\u6837\u5904\u7406\u5462\uff1f\u8fd9\u53c8\u53ef\u4ee5\u5206\u4e3a\u9525\u5f62NAT (CONE NAT)\u4e0e\u5bf9\u79f0NAT (SYMMTRIC NAT)\u4e24\u5927\u7c7b\u6765\u8003\u8651:
\nA.\u9525\u5f62NAT
\n\uff08\u4e3a\u4ec0\u4e48\u53eb\u505a\u9525\u5f62\u5462\uff1f\u8bf7\u770b\u4ee5\u4e0b\u56fe\u5f62,\u7ec8\u7aef\u548c\u5916\u90e8\u670d\u52a1\u5668\uff0c\u90fd\u901a\u8fc7NAT\u5206\u6d3e\u7684\u8fd9\u4e2a\u7ed1\u5b9a\u5730\u5740\u5bf9\u6765\u4f20\u9001\u4fe1\u606f\uff0c\u5c31\u8c61\u4e00\u4e2a\u6f0f\u6597\u4e00\u6837\uff0c\u7b5b\u9009\u5e76\u4f20\u9012\u4fe1\u606f\uff09
\n
\n \u5f53\u5efa\u7acb\u4e86\u4e00\u4e2a [\u79c1\u6709IP:\u7aef\u53e3]-[\u516c\u7f51IP:\u7aef\u53e3] \u7aef\u53e3\u7ed1\u5b9a\u4e4b\u540e\uff0c\u5bf9\u4e8e\u6765\u81ea\u540c\u4e00\u4e2a[\u79c1\u6709IP:\u7aef\u53e3]\u4f1a\u8bdd\uff0c\u9525\u5f62NAT\u670d\u52a1\u5668\u5141\u8bb8\u53d1\u8d77\u4f1a\u8bdd\u7684\u5e94\u7528\u7a0b\u5e8f \u91cd\u590d\u4f7f\u7528\u8fd9\u4e2a\u7aef\u53e3\u7ed1\u5b9a\uff0c\u4e00\u76f4\u5230\u8fd9\u4e2a\u4f1a\u8bdd\u7ed3\u675f\u624d\u89e3\u9664\uff08\u7aef\u53e3\u7ed1\u5b9a\uff09\u3002
\n \u4f8b\u5982\uff0c\u5047\u8bbe Client A\uff08IP\u5730\u5740\u4fe1\u606f\u5982\u4e0a\u56fe\u6240\u793a\uff09\u901a\u8fc7\u4e00\u4e2a\u9525\u5f62NAT \u540c\u65f6\u53d1\u8d77\u4e24\u4e2a\u5916\u51fa\u7684\u8fde\u63a5\uff0c\u5b83\u4f7f\u7528\u540c\u4e00\u4e2a\u5185\u90e8\u7aef\u53e3\uff0810.0.0.1:1234\uff09\u7ed9\u516c\u7f51\u7684\u4e24\u53f0\u4e0d\u540c\u7684\u670d\u52a1\u5668\uff0cS1\u548cS2\u3002\u9525\u5f62NAT \u53ea\u5206\u914d\u4e00\u4e2a\u516c\u7f51IP\u548c\u7aef\u53e3\uff08155.99.25.11:62000\uff09\u7ed9\u8fd9\u4e2a\u4e24\u4e2a\u4f1a\u8bdd\uff0c\u901a\u8fc7\u5730\u5740\u8f6c\u6362\u53ef\u4ee5\u786e\u4fdd Client\u4f7f\u7528\u7aef\u53e3\u7684\u201c\u540c\u4e00\u6027\u201d\uff08\u5373\u8fd9\u4e2aClient\u53ea\u4f7f\u7528\u8fd9\u4e2a\u7aef\u53e3\uff09\u3002\u800c\u57fa\u7840NATs\u548c\u9632\u706b\u5899\u5374\u4e0d\u80fd\u4fee\u6539\u7ecf\u8fc7\u7684\u6570\u636e\u5305\u7aef\u53e3\u53f7\uff0c\u5b83\u4eec\u53ef\u4ee5\u770b\u4f5c\u662f\u9525\u5f62NAT\u7684\u7cbe\u7b80\u7248\u672c\u3002
\n\u8fdb\u4e00\u6b65\u5206\u6790\u53ef\u4ee5\u5c06CONE NAT\u53d7\u9650\u5236\u9525\u5f62NAT (RESTRICT CONE) \u4e0e\u7aef\u53e3\u53d7\u9650\u9525\u5f62NAT (PORT RESTRICT CONE) \u4e09\u5927\u7c7b,\u4ee5\u4e0b\u662f\u8be6\u7ec6\u8bba\u8ff0: \u5206\u4e3a\u5168\u53cc\u5de5\u9525\u5f62NAT (FULL CONE) ,
\n1.\u5168\u53cc\u5de5\u9525\u5f62NAT
\n\u5f53\u5185\u90e8\u4e3b\u673a\u53d1\u51fa\u4e00\u4e2a\u201c\u5916\u51fa\u201d\u7684\u8fde\u63a5\u4f1a\u8bdd\uff0c\u5c31\u4f1a\u521b\u5efa\u4e86\u4e00\u4e2a\u516c\u7f51\/\u79c1\u7f51 \u5730\u5740\uff0c\u4e00\u65e6\u8fd9\u4e2a\u5730\u5740\u5bf9\u88ab\u521b\u5efa\uff0c\u5168\u53cc\u5de5\u9525\u5f62NAT\u4f1a\u63a5\u6536\u968f\u540e\u4efb\u4f55\u5916\u90e8\u7aef\u53e3\u4f20\u5165\u8fd9\u4e2a\u516c\u5171\u7aef\u53e3\u5730\u5740\u7684\u901a\u4fe1\u3002\u56e0\u6b64\uff0c\u5168\u53cc\u5de5\u9525\u5f62NAT\u6709\u65f6\u5019\u53c8\u88ab\u79f0\u4e3a”\u6df7\u6742”NAT\u3002
\n2.\u53d7\u9650\u5236\u9525\u5f62NAT
\n\u53d7\u9650\u5236\u7684\u9525\u5f62NAT\u4f1a\u5bf9\u4f20\u5165\u7684\u6570\u636e\u5305\u8fdb\u884c\u7b5b\u9009\uff0c\u5f53\u5185\u90e8\u4e3b\u673a\u53d1\u51fa\u201c\u5916\u51fa\u201d\u7684\u4f1a\u8bdd\u65f6\uff0cNAT\u4f1a\u8bb0\u5f55\u8fd9\u4e2a\u5916\u90e8\u4e3b\u673a\u7684IP\u5730\u5740\u4fe1\u606f\uff0c\u6240\u4ee5\uff0c\u4e5f\u53ea\u6709\u8fd9\u4e9b\u6709\u8bb0\u5f55\u7684\u5916\u90e8IP\u5730\u5740\uff0c\u80fd\u591f\u5c06\u4fe1\u606f\u4f20\u5165\u5230NAT\u5185\u90e8\uff0c\u53d7\u9650\u5236\u7684\u9525\u5f62NAT \u6709\u6548\u7684\u7ed9\u9632\u706b\u5899\u63d0\u70bc\u4e86\u7b5b\u9009\u5305\u7684\u539f\u5219\u2014\u2014\u5373\u9650\u5b9a\u53ea\u7ed9\u90a3\u4e9b\u5df2\u77e5\u7684\u5916\u90e8\u5730\u5740\u201c\u4f20\u5165\u201d\u4fe1\u606f\u5230NAT\u5185\u90e8\u3002
\n3.\u7aef\u53e3\u53d7\u9650\u9525\u5f62NAT
\n\u7aef\u53e3\u53d7\u9650\u5236\u7684\u9525\u5f62NAT\uff0c\u4e0e\u53d7\u9650\u5236\u7684\u9525\u5f62NAT\u4e0d\u540c\u7684\u662f\uff1a\u5b83\u540c\u65f6\u8bb0\u5f55\u4e86\u5916\u90e8\u4e3b\u673a\u7684IP\u5730\u5740\u548c\u7aef\u53e3\u4fe1\u606f\uff0c\u7aef\u53e3\u53d7\u9650\u5236\u7684\u9525\u5f62NAT\u7ed9\u5185\u90e8\u8282\u70b9\u63d0\u4f9b\u4e86\u540c\u4e00\u7ea7\u522b\u7684\u4fdd\u62a4\uff0c\u5728\u7ef4\u6301\u7aef\u53e3\u201c\u540c\u4e00\u6027\u201d\u8fc7\u7a0b\u4e2d\uff0c\u5c06\u4f1a\u4e22\u5f03\u5bf9\u79f0NAT\u4f20\u56de\u7684\u4fe1\u606f\u3002
\nB.\u5bf9\u79f0NAT
\n\u5bf9\u79f0NAT\uff0c\u4e0eCone NAT\u662f\u5927\u4e0d\u76f8\u540c\u7684\uff0c\u5e76\u4e0d\u5bf9\u4f1a\u8bdd\u8fdb\u884c\u7aef\u53e3\u7ed1\u5b9a\uff0c\u800c\u662f\u5206\u914d\u4e00\u4e2a\u5168\u65b0\u7684\u516c\u7f51\u7aef\u53e3 \u7ed9\u6bcf\u4e00\u4e2a\u65b0\u7684\u4f1a\u8bdd\u3002
\n\u8fd8\u662f\u4e0a\u9762\u90a3\u4e2a\u4f8b\u5b50\uff1a\u5982\u679c Client A (10.0.0.1:1234)\u540c\u65f6\u53d1\u8d77\u4e24\u4e2a “\u5916\u51fa” \u4f1a\u8bdd,\u5206\u522b\u53d1\u5f80S1\u548cS2\u3002\u5bf9\u79f0Nat\u4f1a\u5206\u914d\u516c\u5171\u5730\u5740155.99.25.11:62000\u7ed9Session1\uff0c\u7136\u540e\u5206\u914d\u53e6\u4e00\u4e2a\u4e0d\u540c\u7684\u516c\u5171\u5730\u5740155.99.25.11:62001\u7ed9Session2\u3002\u5bf9\u79f0Nat\u80fd\u591f\u533a\u522b\u4e24\u4e2a\u4e0d\u540c\u7684\u4f1a\u8bdd\u5e76\u8fdb\u884c\u5730\u5740\u8f6c\u6362\uff0c\u56e0\u4e3a\u5728 Session1 \u548c Session2\u4e2d\u7684\u5916\u90e8\u5730\u5740\u662f\u4e0d\u540c\u7684\uff0c\u6b63\u662f\u56e0\u4e3a\u8fd9\u6837\uff0cClient\u7aef\u7684\u5e94\u7528\u7a0b\u5e8f\u5c31\u8ff7\u5931\u5728\u8fd9\u4e2a\u5730\u5740\u8f6c\u6362\u8fb9\u754c\u7ebf\u4e86\uff0c\u56e0\u4e3a\u8fd9\u4e2a\u5e94\u7528\u7a0b\u5e8f\u6bcf\u53d1\u51fa\u4e00\u4e2a\u4f1a\u8bdd\u90fd\u4f1a\u4f7f\u7528\u4e00\u4e2a\u65b0\u7684\u7aef\u53e3\uff0c\u65e0\u6cd5\u4fdd\u969c\u53ea\u4f7f\u7528\u540c\u4e00\u4e2a\u7aef\u53e3\u4e86\u3002
\n\u5728TCP\u548cUDP\u901a\u4fe1\u4e2d\uff0c\uff08\u5230\u5e95\u662f\u4f7f\u7528\u540c\u4e00\u4e2a\u7aef\u53e3\uff0c\u8fd8\u662f\u5206\u914d\u4e0d\u540c\u7684\u7aef\u53e3\u7ed9\u540c\u4e00\u4e2a\u5e94\u7528\u7a0b\u5e8f\uff09\uff0c\u9525\u5f62NAT\u548c\u5bf9\u79f0NAT\u5404\u6709\u5404\u7684\u7406\u7531\u3002\u5f53\u7136\u9525\u5f62NAT\u5728\u6839\u636e\u5982\u4f55\u516c\u5e73\u5730\u5c06NAT\u63a5\u53d7\u7684\u8fde\u63a5\u76f4\u8fbe\u4e00\u4e2a\u5df2\u521b\u5efa\u7684\u5730\u5740\u5bf9\u4e0a\u6709\u66f4\u591a\u7684\u5206\u7c7b\u3002\u8fd9\u4e2a\u5206\u7c7b\u4e00\u822c\u5e94\u7528\u5728Udp\u901a\u4fe1\uff08\u800c\u4e0d\u662fTcp\u901a\u4fe1\u4e0a\uff09\uff0c\u56e0\u4e3aNATs\u548c\u9632\u706b\u5899\u963b\u6b62\u4e86\u8bd5\u56fe\u65e0\u6761\u4ef6\u4f20\u5165\u7684TCP\u8fde\u63a5\uff0c\u9664\u975e\u660e\u786e\u8bbe\u7f6eNAT\u4e0d\u8fd9\u6837\u505a\u3002
\n\u4e09:NAT\u5bf9session\u7684\u5904\u7406
\n\u4ee5\u4e0b\u5206\u6790NAPT\u662f\u4f9d\u636e\u4ec0\u4e48\u7b56\u7565\u6765\u5224\u65ad\u662f\u5426\u8981\u4e3a\u4e00\u4e2a\u8bf7\u6c42\u53d1\u51fa\u7684UDP\u6570\u636e\u5305\u5efa\u7acbSession\u7684.\u4e3b\u8981\u6709\u4e00\u4e0b\u51e0\u4e2a\u7b56\u7565:
\nA. \u6e90\u5730\u5740(\u5185\u7f51IP\u5730\u5740)\u4e0d\u540c\uff0c\u5ffd\u7565\u5176\u5b83\u56e0\u7d20, \u5728NAPT\u4e0a\u80af\u5b9a\u5bf9\u5e94\u4e0d\u540c\u7684Session
\nB. \u6e90\u5730\u5740(\u5185\u7f51IP\u5730\u5740)\u76f8\u540c\uff0c\u6e90\u7aef\u53e3\u4e0d\u540c\uff0c\u5ffd\u7565\u5176\u5b83\u7684\u56e0\u7d20\uff0c\u5219\u5728NAPT\u4e0a\u4e5f\u80af\u5b9a\u5bf9\u5e94\u4e0d\u540c\u7684Session
\nC. \u6e90\u5730\u5740(\u5185\u7f51IP\u5730\u5740)\u76f8\u540c\uff0c\u6e90\u7aef\u53e3\u76f8\u540c\uff0c\u76ee\u7684\u5730\u5740(\u516c\u7f51IP\u5730\u5740)\u76f8\u540c\uff0c\u76ee\u7684\u7aef\u53e3\u4e0d\u540c\uff0c\u5219\u5728NAPT\u4e0a\u80af\u5b9a\u5bf9\u5e94\u540c\u4e00\u4e2aSession
\nD. \u6e90\u5730\u5740(\u5185\u7f51IP\u5730\u5740)\u76f8\u540c\uff0c\u6e90\u7aef\u53e3\u76f8\u540c\uff0c\u76ee\u7684\u5730\u5740(\u516c\u7f51IP\u5730\u5740)\u4e0d\u540c\uff0c\u5ffd\u7565\u76ee\u7684\u7aef\u53e3\uff0c\u5219\u5728NAPT\u4e0a\u662f\u5982\u4f55\u5904\u7406Session\u7684\u5462\uff1f
\nA,B,C\u4e09\u79cd\u60c5\u51b5\u7684\u90fd\u662f\u6bd4\u8f83\u7b80\u5355\u7684,\u53ef\u4ee5\u5f88\u5bb9\u6613\u7684\u5b9e\u73b0.\u800cD\u7684\u60c5\u51b5\u5c31\u6bd4\u8f83\u590d\u6742\u4e86.\u6240\u4ee5D\u60c5\u51b5\u624d\u662f\u6211\u4eec\u8981\u91cd\u70b9\u5173\u5fc3\u548c\u8ba8\u8bba\u7684\u95ee\u9898\u3002
\n\u56db:\u5b8c\u5168\u89e3\u51b3\u65b9\u6848
\n\u4ee5\u4e0b\u9488\u5bf9\u56db\u79cdSESSION\u4e0e\u56db\u79cdNAT\u7684\u5b8c\u5168\u89e3\u51b3\u65b9\u6848,\u4e3a\u4e86\u65b9\u4fbf\u5c06\u4f7f\u7528\u4ee5\u4e0b\u7f29\u5199\u5f62\u5f0f:
\nC\u4ee3\u8868 CONE NAT
\nS\u4ee3\u8868SYMMETRIC NAT,
\nFC\u4ee3\u8868 FULL CONE NAT,
\nRC\u4ee3\u8868 RESTRICT CONE NAT,
\nPC \u4ee3\u8868 PORT RESTRICT CONE NAT.
\n\u9996\u5148\u4f9d\u636eCLIENT (\u5ba2\u6237)\u7aef\u5728NAT\u540e \u7684\u4e2a\u6570\u4e0d\u540c\u53ef\u4ee5\u5206\u4e3a\u4e24\u5927\u7c7b:
\nTYPE ONE :\u4e00\u4e2a\u5728NAT\u540e + \u4e00\u4e2a\u5728\u516c\u7f51\u4e2d.
\n\u8fd9\u79cd\u60c5\u51b5\u4e0b\u53ef\u4ee5\u5206\u4e3a\u4e24\u5927\u7c7b:
\nA. S VS \u516c\u7f51:\u6b64\u79cd\u60c5\u51b5\u4e0b,\u7531\u4e8e\u516c\u7f51\u7684\u5730\u5740\u5728\u4e00\u4e2aSESSION\u5185\u662f\u4e0d\u53d8\u7684,\u6240\u4ee5\u53ef\u4ee5\u6253\u6d1e\u662f\u53ef\u4ee5\u6210\u529f\u7684.
\nB. C VS \u516c\u7f51: \u4e0e\u4e0a\u9762\u7c7b\u4f3c,\u8fd9\u79cd\u60c5\u53e3\u4e0b\u6253\u6d1e\u662f\u53ef\u4ee5\u6210\u529f\u7684.
\nTYPE TWO:\u4e24\u4e2a\u5ba2\u6237\u90fd\u5728NAT\u540e\u9762.
\n\u8fd9\u79cd\u60c5\u51b5\u4e0b\u4e5f\u53ef\u4ee5\u7ec6\u5206\u4e3a\u4e24\u5927\u7c7b:
\nA. \u5176\u4e2d\u4e00\u4e2aNAT \u662f S(SYMMETRIC NAT) \u578b\u7684,\u65e2:S VS C\u6216\u8005\u662fS VS S .
\n\u4e0b\u9762\u8bba\u8bc1\u8fd9\u79cd\u60c5\u53e3\u4e0b\u6309\u7167\u5e38\u89c4\u6253\u6d1e\u662f\u884c\u4e0d\u901a\u7684,\u5728\u5e38\u89c4\u6253\u6d1e\u4e2d,\u6240\u6709\u7684\u5ba2\u6237\u9996\u5148\u767b\u9646\u5230\u4e00\u4e2a\u670d\u52a1\u5668\u4e0a\u53bb.\u670d\u52a1\u5668\u8bb0\u5f55\u4e0b\u6bcf\u4e2a\u5ba2\u6237\u7684[\u516c\u7f51IP:\u7aef\u53e3],\u7136\u540e\u5728\u6253\u6d1e\u8fc7\u7a0b\u4e2d\u5c31\u4f7f\u7528\u8fd9\u4e2a\u8bb0\u5f55\u7684\u503c,\u7136\u800c\u5bf9\u4e8eS\u578b\u7684NAT\u6765\u8bf4,\u5b83\u5e76\u4e0d\u7ed1\u5b9a[\u79c1\u7f51IP:\u7aef\u53e3]\u548c[\u516c\u7f51IP:\u7aef\u53e3]\u7684\u6620\u5c04.\u6240\u4ee5\u5728\u4e0d\u540c\u7684SESSION\u4e2d,NAT\u5c06\u4f1a\u91cd\u65b0\u5206\u914d\u4e00\u5bf9[\u516c\u7f51IP:\u7aef\u53e3].\u8fd9\u6837\u4e00\u6765\u5bf9\u4e8eS\u578b\u7684NAT\u6765\u8bf4\u6253\u6d1e\u7684[\u516c\u7f51IP:\u7aef\u53e3]\u4e0e\u767b\u8bb0\u5728\u670d\u52a1\u5668\u4e0a\u7684[\u516c\u7f51IP:\u7aef\u53e3]\u662f\u4e0d\u540c\u7684.\u800c\u4e14\u4e5f\u6ca1\u6709\u529e\u6cd5\u5c06\u6253\u6d1e\u7684[\u516c\u7f51IP:\u7aef\u53e3]\u901a\u77e5\u5230\u53e6\u4e00\u4e2a\u4f4d\u4e8eNAT\u4e0b\u7684\u5ba2\u6237\u7aef, \u6240\u4ee5\u6253\u6d1e\u662f\u4e0d\u4f1a\u6210\u529f\u7684.\u7136\u800c\u5982\u679c\u53e6\u4e00\u4e2a\u5ba2\u6237\u7aef\u662f\u5728\u516c\u7f51\u65f6,\u6253\u6d1e\u662f\u53ef\u4ee5\u7684.\u524d\u9762\u5df2\u7ecf\u8bba\u8bc1\u4e86\u8fd9\u79cd\u60c5\u51b5.
\n\u8fd9\u79cd\u60c5\u51b5\u4e0b\u7684\u89e3\u51b3\u65b9\u6848\u662f\u53ea\u80fd\u901a\u8fc7\u7aef\u53e3\u9884\u6d4b\u6765\u8fdb\u884c\u6253\u6d1e,\u5177\u4f53\u89e3\u51b3\u65b9\u6cd5\u5982\u4e0b:\u4f8b\u5982(\u4ee5\u4e24\u4e2a\u90fd\u662fS\u578b\u7684\u4e3a\u4f8b) NAT A \u5206\u914d\u4e86\u5b83\u81ea\u5df1\u7684UDP\u7aef\u53e362000\uff0c\u7528\u6765\u4fdd\u6301 \u5ba2\u6237\u7aefA \u4e0e\u670d\u52a1\u5668S\u7684\u901a\u4fe1\u4f1a\u8bdd\uff0c NAT B \u4e5f\u5206\u914d\u4e8631000\u7aef\u53e3\uff0c\u7528\u6765\u4fdd\u6301\u5ba2\u6237\u7aefB\u4e0e\u670d\u52a1\u5668S \u7684\u901a\u4fe1\u4f1a\u8bdd\u3002\u901a\u8fc7\u4e0e \u670d\u52a1\u5668S\u7684\u5bf9\u8bdd\uff0c\u5ba2\u6237\u7aefA \u548c \u5ba2\u6237\u7aefB\u90fd\u76f8\u4e92\u77e5\u9053\u4e86\u5bf9\u65b9\u6240\u6620\u5c04\u7684\u771f\u5b9eIP\u548c\u7aef\u53e3\u3002
\n \u5ba2\u6237\u7aefA\u53d1\u9001\u4e00\u6761UDP\u6d88\u606f\u5230138.76.29.7:31001(\u8bf7\u6ce8\u610f\u5230\u7aef\u53e3\u53f7\u7684\u589e\u52a0)\uff0c\u540c\u65f6\u5ba2\u6237\u7aefB\u53d1\u9001\u4e00\u6761UDP\u6d88\u606f\u5230155.99.25.11:62001\u3002\u5982\u679cNAT A \u548cNAT B\u7ee7\u7eed\u5206\u914d\u7aef\u53e3\u7ed9\u65b0\u7684\u4f1a\u8bdd\uff0c\u5e76\u4e14\u4eceA-S\u548cB-S\u7684\u4f1a\u8bdd\u65f6\u95f4\u6d88\u8017\u5f97\u5e76\u4e0d\u591a\u7684\u8bdd\uff0c\u90a3\u4e48\u4e00\u6761\u5904\u4e8e\u5ba2\u6237\u7aefA\u548c\u5ba2\u6237\u7aefB\u4e4b\u95f4\u7684\u53cc\u5411\u4f1a\u8bdd\u901a\u9053\u5c31\u5efa\u7acb\u4e86\u3002
\n \u5ba2\u6237\u7aefA\u53d1\u51fa\u7684\u6d88\u606f\u9001\u8fbeB\u5bfc\u81f4\u4e86NAT A\u6253\u5f00\u4e86\u4e00\u4e2a\u65b0\u7684\u4f1a\u8bdd\uff0c\u5e76\u4e14\u6211\u4eec\u5e0c\u671bNAT A\u5c06\u4f1a\u6307\u6d3e62001\u7aef\u53e3\u7ed9\u8fd9\u4e2a\u65b0\u7684\u4f1a\u8bdd\uff0c\u56e0\u4e3a62001\u662f\u7ee762000\u540e\uff0cNAT\u4f1a\u81ea\u52a8\u6307\u6d3e\u7ed9 \u4ece\u670d\u52a1\u5668S\u5230\u5ba2\u6237\u7aefA\u4e4b\u95f4\u7684\u65b0\u4f1a\u8bdd\u7684\u7aef\u53e3\u53f7\uff1b\u7c7b\u4f3c\u7684\uff0c\u5ba2\u6237\u7aefB\u53d1\u51fa\u7684\u6d88\u606f\u9001\u8fbeA\u5bfc\u81f4\u4e86 NAT B\u6253\u5f00\u4e86\u4e00\u4e2a\u65b0\u7684\u4f1a\u8bdd\uff0c\u5e76\u4e14\u6211\u4eec\u5e0c\u671b NAT B\u5c06\u4f1a\u6307\u6d3e31001\u8fd9\u4e2a\u7aef\u53e3\u7ed9\u65b0\u7684\u4f1a\u8bdd\uff1b\u5982\u679c\u4e24\u4e2a\u5ba2\u6237\u7aef\u90fd\u6b63\u786e\u7684\u731c\u6d4b\u5230\u4e86\u5bf9\u65b9\u65b0\u4f1a\u8bdd\u88ab\u6307\u6d3e\u7684\u7aef\u53e3\u53f7\uff0c\u90a3\u4e48\u8fd9\u4e2a \u5ba2\u6237\u7aefA\uff0d\u5ba2\u6237\u7aefB\u7684\u53cc\u5411\u8fde\u63a5\u5c31\u88ab\u6253\u901a\u4e86\u3002\u5176\u7ed3\u679c\u5982\u4e0b\u56fe\u6240\u793a\uff1a
\n\u660e\u663e\u7684\uff0c\u6709\u8bb8\u591a\u56e0\u7d20\u4f1a\u5bfc\u81f4\u8fd9\u4e2a\u65b9\u6cd5\u5931\u8d25\uff1a\u5982\u679c\u8fd9\u4e2a\u9884\u8a00\u7684\u65b0\u7aef\u53e3\uff0862001\u548c31001\uff09 \u6070\u597d\u5df2\u7ecf\u88ab\u4e00\u4e2a\u4e0d\u76f8\u5173\u7684\u4f1a\u8bdd\u6240\u4f7f\u7528\uff0c\u90a3\u4e48NAT\u5c31\u4f1a\u8df3\u8fc7\u8fd9\u4e2a\u7aef\u53e3\u53f7\uff0c\u8fd9\u4e2a\u8fde\u63a5\u5c31\u4f1a\u5ba3\u544a\u5931\u8d25\uff1b\u5982\u679c\u4e24\u4e2aNAT\u6709\u65f6\u6216\u8005\u603b\u662f\u4e0d\u6309\u7167\u987a\u5e8f\u6765\u751f\u6210\u65b0\u7684\u7aef\u53e3\u53f7\uff0c\u90a3\u4e48\u8fd9\u4e2a\u65b9\u6cd5\u4e5f\u662f\u884c\u4e0d\u901a\u7684\u3002
\n\u5982\u679c\u9690\u85cf\u5728NATA\u540e\u7684\u4e00\u4e2a\u4e0d\u540c\u7684\u5ba2\u6237\u7aefX\uff08\u6216\u8005\u5728NAT B\u540e\uff09\u6253\u5f00\u4e86\u4e00\u4e2a\u65b0\u7684\u201c\u5916\u51fa\u201dUDP \u8fde\u63a5\uff0c\u5e76\u4e14\u65e0\u8bba\u8fd9\u4e2a\u8fde\u63a5\u7684\u76ee\u7684\u5982\u4f55\uff1b\u53ea\u8981\u8fd9\u4e2a\u52a8\u4f5c\u53d1\u751f\u5728\u5ba2\u6237\u7aefA \u5efa\u7acb\u4e86\u4e0e\u670d\u52a1\u5668S\u7684\u8fde\u63a5\u4e4b\u540e\uff0c\u5ba2\u6237\u7aefA \u4e0e \u5ba2\u6237\u7aefB \u5efa\u7acb\u8fde\u63a5\u4e4b\u524d\uff1b\u90a3\u4e48\u8fd9\u4e2a\u65e0\u5173\u7684\u5ba2\u6237\u7aefX \u5c31\u4f1a\u8d81\u4eba\u4e0d\u5907\u5730\u201c\u5077\u201d \u5230\u8fd9\u4e2a\u6211\u4eec\u6e34\u671b\u5206\u914d\u7684\u7aef\u53e3\u3002\u6240\u4ee5\uff0c\u8fd9\u4e2a\u65b9\u6cd5\u53d8\u5f97\u5982\u6b64\u8106\u5f31\u800c\u4e14\u4e0d\u582a\u4e00\u51fb\uff0c\u53ea\u8981\u4efb\u4f55\u4e00\u4e2aNAT\u65b9\u5305\u542b\u4ee5\u4e0a\u78b0\u5230\u7684\u95ee\u9898\uff0c\u8fd9\u4e2a\u65b9\u6cd5\u90fd\u4e0d\u4f1a\u594f\u6548\u3002
\n\u5728\u5904\u4e8e cone NAT \u7cfb\u5217\u7684\u7f51\u7edc\u73af\u5883\u4e2d\u8fd9\u4e2a\u65b9\u6cd5\u8fd8\u662f\u5b9e\u7528\u7684\uff1b\u5982\u679c\u6709\u4e00\u65b9\u4e3a cone NAT \u800c\u53e6\u5916\u4e00\u65b9\u4e3a symmetric NAT\uff0c\u90a3\u4e48\u5e94\u7528\u7a0b\u5e8f\u5c31\u5e94\u8be5\u9884\u5148\u53d1\u73b0\u53e6\u5916\u4e00\u65b9\u7684 NAT \u662f\u4ec0\u4e48\u7c7b\u578b\uff0c\u518d\u505a\u51fa\u6b63\u786e\u7684\u884c\u4e3a\u6765\u5904\u7406\u901a\u4fe1\uff0c\u8fd9\u6837\u5c31\u589e\u5927\u4e86\u7b97\u6cd5\u7684\u590d\u6742\u5ea6\uff0c\u5e76\u4e14\u964d\u4f4e\u4e86\u5728\u771f\u5b9e\u7f51\u7edc\u73af\u5883\u4e2d\u7684\u666e\u9002\u6027\u3002
\n \u6700\u540e\uff0c\u5982\u679cP2P\u7684\u4e00\u65b9\u5904\u5728\u4e24\u7ea7\u6216\u8005\u4e24\u7ea7\u4ee5\u4e0a\u7684NAT\u4e0b\u9762\uff0c\u5e76\u4e14\u8fd9\u4e9bNATS \u63a5\u8fd1\u8fd9\u4e2a\u5ba2\u6237\u7aef\u662fSYMMETRIC NAT\u7684\u8bdd\uff0c\u7aef\u53e3\u53f7\u9884\u8a00\u662f\u65e0\u6548\u7684\uff01
\n\u56e0\u6b64\uff0c\u5e76\u4e0d\u63a8\u8350\u4f7f\u7528\u8fd9\u4e2a\u65b9\u6cd5\u6765\u5199\u65b0\u7684P2P\u5e94\u7528\u7a0b\u5e8f\uff0c\u8fd9\u4e5f\u662f\u5386\u53f2\u7684\u7ecf\u9a8c\u548c\u6559\u8bad\uff01
\nB. \u4e24\u4e2a\u90fd\u662fCONE NAT\u578b\u7684.
\n\u8fd9\u79cd\u60c5\u51b5\u4e0b\u53ef\u4ee5\u5206\u4e3a\u516d\u5927\u7c7b\u578b:
\nA: FC + FC
\nB: FC + RC
\nC: FC + PC
\nD: PC + RC
\nE: PC + PC
\nF: RC + RC
\n\u867d\u7136\u6709\u8fd9\u4e48\u591a\u79cd\u60c5\u51b5,\u4f46\u662f\u7531\u4e8eCONE NAT \u7684\u7279\u6027,\u6240\u4ee5\u8fd8\u662f\u5f88\u597d\u529e\u7684,\u56e0\u4e3a\u5bf9\u4e8eCONE NAT \u6765\u8bf4,\u5728\u540c\u4e00\u4e2aSESSION\u4e2d\u5b83\u4f1a\u7ed1\u5b9a\u4e00\u5bf9[\u79c1\u7f51IP:\u7aef\u53e3]\u548c[\u516c\u7f51IP:\u7aef\u53e3]\u7684\u6620\u5c04,\u6240\u4ee5\u5b83\u4eec\u6253\u6d1e\u7528\u7684[\u516c\u7f51IP:\u7aef\u53e3]\u4e0e\u767b\u8bb0\u5728\u670d\u52a1\u5668\u4e0a\u7684[\u516c\u7f51IP:\u7aef\u53e3]\u662f\u4e00\u81f4\u7684,\u6240\u4ee5\u6253\u6d1e\u662f\u53ef\u4ee5\u884c\u7684\u901a\u7684.
\n\u7efc\u4e0a\u6240\u8ff0,\u5c31\u5df2\u7ecf\u5b8c\u5168\u7684\u6982\u62ec\u4e86\u6240\u6709\u7c7b\u578b\u7684NAT\u4e4b\u95f4\u7684\u53ef\u80fd\u7684\u901a\u4fe1\u60c5\u51b5\u4e86.\u5e76\u4e14\u90fd\u63d0\u4f9b\u4e86\u53ef\u884c\u7684\u89e3\u51b3\u65b9\u6848.
\n\u4e94:\u5bf9\u524d\u4e00\u9636\u6bb5\u7684\u603b\u7ed3
\n1.\u524d\u4e00\u9636\u6bb5\u4f7f\u7528\u7684\u6253\u6d1e\u65b9\u6cd5\u662f\u6709\u7f3a\u9677\u7684,\u5b83\u53ea\u9002\u5e94\u4e8e\u4e24\u4e2a\u90fd\u662fFULL CONE NAT\u7684\u7c7b\u578b\u7684CLIENT(\u5ba2\u6237\u7aef).\u4ee5\u4e0b\u8bba\u8bc1\u5b83\u4e0d\u9002\u5e94\u4e8e\u4e24\u4e2a\u90fd\u662fCONE NAT\u7684\u7c7b\u578b\u4e2d\u7684
\nB: FC + RC
\nC: FC + PC
\nD: PC + RC
\nE: PC + PC
\nF: RC + RC
\n\u8fd9\u4e94\u79cd\u60c5\u51b5.
\n\u56e0\u4e3a\u5bf9\u4e8e\u53d7\u9650\u7684NAT\u5b83\u767b\u8bb0\u4e86\u5916\u51fa\u5305\u7684[IP\u5730\u5740\uff06\u7aef\u53e3],\u5b83\u4ec5\u4ec5\u63a5\u53d7\u8fd9\u4e9b\u5df2\u767b\u8bb0\u5730\u5740\u53d1\u8fc7\u6765\u7684\u5305,\u6240\u4ee5\u5b83\u4eec\u62a5\u544a\u670d\u52a1\u5668\u7684\u7aef\u53e3\u53ea\u80fd\u63a5\u53d7\u6765\u81ea\u670d\u52a1\u5668\u7684\u5305.\u4e0d\u80fd\u63a5\u53d7\u6765\u81ea\u53e6\u4e00\u5ba2\u6237\u7aef\u7684\u5305.\u6240\u4ee5\u524d\u4e00\u9636\u6bb5\u7684\u6253\u6d1e\u65b9\u6cd5\u662f\u4e0d\u53ef\u884c\u7684.
\n\u516d: \u5b58\u5728\u7684\u95ee\u9898
\n\u6309\u7167\u7406\u8bba.NAT\u5c06\u5728\u4e00\u5b9a\u65f6\u95f4\u540e\u5173\u95edUDP\u7684\u4e00\u4e2a\u6620\u5c04,\u6240\u4ee5\u4e3a\u4e86\u4fdd\u6301\u4e0e\u670d\u52a1\u5668\u80fd\u591f\u4e00\u76f4\u901a\u4fe1,\u670d\u52a1\u5668\u5fc5\u987b\u8981\u53d1\u9001UDP\u5fc3\u8df3\u5305,\u6765\u4fdd\u6301\u6620\u5c04\u4e0d\u88ab\u5173\u95ed.\u8fd9\u5c31\u9700\u8981\u4e00\u4e2a\u5408\u9002\u7684\u65f6\u95f4\u503c<\/p>\n","protected":false},"excerpt":{"rendered":"
\u8fd9\u91cc\u6211\u4eec\u4e3b\u8981\u662f\u662f\u7b80\u5355\u8bb2\u89e3\u4e00\u4e0bUDP\u5b9e\u73b0NAT\u7684\u7a7f\u900f\uff08\u4fd7\u79f0\u6253\u6d1e\uff09
\n\u5f53\u7136TCP\u4e0e\u4e4b\u76f8\u4f3c\uff0c\u53ef\u4ee5\u4ee5\u6b64\u7c7b\u63a8\u3002<\/p>\n
NAT\u6700\u5f00\u59cb\u51fa\u73b0\u5728\u8def\u7531\u5668\u4e0a\u3002\u8be6\u7ec6\u7684\u5927\u5bb6\u53ef\u4ee5\u5728\u7f51\u4e0a\u67e5\u4e0b\u8d44\u6599
\nNAT\u7684\u5168\u79f0\u662fNetwork Address Translator\u4e2d\u6587\u79f0\u4e4b\u4e3a\u7f51\u7edc\u5730\u5740\u8f6c\u6362
\nNAT\u5206\u4e3a\u4e24\u5927\u7c7b\uff0cNAT\u548cNAPT\uff08Network Address Port Translator\uff09\u8fd9\u4e2a\u4e0d\u7528\u8bf4\u4e86\uff0c\u7aef\u53e3\u5730\u5740\u8f6c\u6362\u3002<\/p>\n
\u7528\u4e8e\u5b9e\u4f8b\uff0c\u7b80\u5355\u7684\u8bf4\uff0c\u5b9e…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[333],"tags":[],"class_list":["post-117","post","type-post","status-publish","format-standard","hentry"],"yoast_head":"\n