R-IN32 TCP/IP Stack FTP does not accept "PASV" command

Hi,

my name is alfred, working for a small company developing optical sensors.

Using R-IN32M3-EC with the TCP/IP Stack code from Renesas ( libunet3bsd...) do not have source code of this.

All working, using UDP, HTTP-Server, and so on, all ok.

But:

If i want to use FTP. all works eccept "PASV" (switch to passive mode ) command.

get "unknown command error 500" on client if i send PASV to server.

In header of ftp_server.h this command is defined:

/* FTP Commands */
enum {
FTP_CMD_NONE,
FTP_CMD_USER,
FTP_CMD_PASS,
FTP_CMD_QUIT,
FTP_CMD_PORT,
FTP_CMD_PASV,
FTP_CMD_EPSV,
FTP_CMD_LIST,
FTP_CMD_TYPE,
FTP_CMD_STOR,
FTP_CMD_RETR,
FTP_CMD_SIZE,
FTP_CMD_ABOR,
FTP_CMD_REST,
FTP_CMD_EPRT,
FTP_CMD_ERR
};

Lot of commands work, but "PASV" does not work.

Can not debug this because, do not have source code.

I have to run FTP in "Passive Mode", only  for a trial, if i run it in "active mode" without switching to "passive mode"  FTP works ok.

What can i do ?

Thank you.

Best regards, Alfred.