wu-ftp error: 425 Can't create data socket

[Debbie Fleith]

We have an older Linux server running a modified wu-ftp deamon on port 3021/tcp, data 3020/tcp. We are trying to ftp to the Linux server from a Microsoft client next to it within our LAN, inside the firewall. After we login successfully from a client and cd to the right place successfully, we cannot mput the files we need to transfer. We use this custom ftp deamon on many other like systems without this problem. Here is the error we are getting:
==============
ftp> mput *
200 Port command successful.
425 Can't create data socket (120.116.0.22,3020): Cannot assign requested address.
==============
Can anyone help me understand this error? The address is not recognizable on our LAN.

[Ivan Ferreira]

¿Is the IP address correct? (120.116.0.22) ¿Can you ftp and mput from localhost?

[Debbie Fleith]

The ip address isn't anything we recognize on our LAN. Yes, we can use regular ftp at port 21 for mput between these two systems just fine.

[Steven Schweda]

What _are_ the IP addresses of these systems?

[Debbie Fleith]

The linux server running the custom ftp daemon is at IP 10.100.0.22, the Microsoft client initiating the request is 10.100.0.26