I have a situation where my server is hosted in cloud env ( dedicated server provided by a service provider) running centos and pure-ftpd server. My client would like to ftp some files to this server. I have created the necessary ftp userid/pwd, port 21 for ftp and also opened up ports 30000-50000 for passive mode communication (both in iptables firewall entry and in pure-ftpd.conf file).
The issue is that the client PC is behind a http proxy server. When I run the winscp from my env (which doesn't have proxy server) I am able to connect and see the ftp home directory (there are no files transferred to this directory yet). When the client attempts the same ftp connection from behind his proxy server (within his company), he is not able to make a connection even to see the directory listing. You will notice the errors that are showing up in the log file.
Attached herewith are two log file (with and without proxy). Can you please help as to where the issue might be?