Some question about creating DataConnection, when exists NAT. In the following sence , it happen some wrong when creating DataConnection . Sence: ftp server Listening at inner ip : 10.1.100.34 port 21 ftp client is behind the firewall , ftpServer inner ip through NAT is 192.168.2.1. in the ftp client’s command console: ftp 192.168.2.1 user:xxxx pass:xxxx can connected passive return: entering passive mode ( 10.1.00.34 port) ftpserver return inner ip ,not after NAT ip(192.168.2.1) client can’t connect inner ip, so connection is time out. Because , ftpserver return’s message is ISO seventh layer datagram, router device just convert IP layer datagram. Modify some class to solve the problem: 1. SocketClient class Add var : private String _set_passive_host_ip In connect method : add: _set_passive_host_ip = hostname; 2. FTPClient class In __parsePassiveModeReply method: Add: __passiveHost = _set_passive_host_ip; Use connect method parameter “hostname” as dataconnection “ip”.
