Ftp Timing Out From X11



I'm having problems with ftp services with Mac OS X. I open a terminal window and type ftp followed by the DNS. Connect to ftp server, log on, change to appropriate directory. If I type "ls" I get 229 entering extended passive mode (|||53637|) and then everything seems to stall out. Eventually I get 500 Illegal EPRT command followed by 200 PORT command successful and everything stalls again. Next I receive 421 Service not available, remote server timed out connection failed.

This happens on every FTP server I've tried to access which makes me think that I need to configure my machine but not sure where to start.

Thanks for your help,