I have a Windows Server 2016 with two cards acting as a router. A WAN card connects to the router and another LAN card connects to the switch that serves the workstations and peripherals. Everything works correctly, the PCs go to the internet (Web, mail, etc ...) without problems, but we can not use any FTP client to connect to any external FTP server. I have tried to enable port 21 for example in the client and server firewall and nothing. The same PC, outside the network connecting against the router for example, works correctly. Does anyone know if the FTP protocol can be routed to work and how? We almost daily need to connect with some client servers and providers, to pick up and leave some files.
Thanks in advance.