We have a Wing FTP server 3.5.0 installed on a Windows Server 2003 R2 SP2 and located on a DMZ with ISA Server 2006 R2 publishing this server . Users are able to connect from Internal network using windows FTP client, FileZilla ,IE8 -both passive and active modes and also through HTTP and HTTPS .
Internet Clients can however connect only in passive mode and not active mode ; also some external clients using FTP Proxy get a message 'Connection closed by remote host' using NcFTP . The client wants to know if Wing FTP will allow inbound connections from a FTP proxy . I understand a FTP Proxy is different from a generic proxy .
This is the scenario in our ISA 2006 .
1. FTP publishing rule to internal IP . -Tested working for external clients not using FTP Proxy.
2. Ports allowed inbound are 21,990,22222-22272 and 22.
3.Ports allowed outbound are 20 and 989 and estabilished traffic. ISA is stateful packet inspection , so it should understand 20 and 989 as estabilished connections. However this is not working .
Not getting external clients to connect using Active mode is ok for us but we need to allow the external clients from a FTP Proxy in Passive mode using NcFTP and Sysax FTP automation .