Port Forwarding Problem
We have a Passive/Active FTP Server running on OpenBSD 3.6 box behind a Windows XP Professional Gateway. We have to give Access to the FTP Server from the Internet. We have tried to set a port forwarder utility on Windows Box but the problem is that FTP uses two channels for it's communication. Do you have any solution for the following:
(1) A port forwarder which replaces local IP to External IP (i think NAT redirection)
client IP is required at local interface of FTP Server, because FTP Server in Active mode create connection to this IP.
In Passive mode server waits for the connection on the range of Ports from the Client. Server tells about this Port using PORT Command to the client. The PORT command carry server's IP too, which is local if it is not replaced by the External IP, thus result in forever wait for the client to connect at a private IP.
(2) Forwards a range of Ports. Passive FtP Operation (large number of ports at FTP Server)
[ FTP ]<----------->[Win XP Pro ]<----->Internet
[ Server ]21,x1:x2 [ICS Gateway]
192.168.1.2 192.168.1.1 x.x.x.x
(ISP assigned IP)
x1:x2 is a range of ports.
ICS = Internet Connection Sharing
