I have two computers connected by LAN and one of them acts as router and give internet to the other one computer - client. Installed Red Hat 9 to the router and configured by to share internet connection by ipchains .

Everything seems OK and was but few days later after installation tried from the client computer to access to one ftp server but could't browse the directories from them. I tried to access to another one but the result was same: the ftp client can list files/directories from the server, tried also with other ftp clients: same . But the most strange thing was that the ftp client can download files from ftp server if entered full path. Example:
ftp client can download file like: ftp.someserver.com/files/example.txt ,but can't show what have in ftp.someserver.com/files/ directory and the root directory of the ftp server ftp.someserver.com .

Any ideas why it happens