Error while connecting via HTTP proxy, but works without proxy

Hi,

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?

Thanks

It looks like the proxy does not let the data connection (port 42190) though. Is the client able to connect to any other FTP server?

martin wrote:

It looks like the proxy does not let the data connection (port 42190) though. Is the client able to connect to any other FTP server?

Thanks for your reply..

The confusing part is that the client indicates that he is able to FTP using WinSCP and HTTP proxy to other servers, but not to my server. So wasn't sure what else can be deciphered from the logs, for any changes to ftp server or WinSCP for getting the connection to work.

Further the client is also able to ftp to my server, if he connects via a PC NOT behind the http proxy.

Sriram V.

Maybe the other servers use a different port range, or an active mode. Can you get a log of a connection to the other server(s)?

martin wrote:

Maybe the other servers use a different port range, or an active mode. Can you get a log of a connection to the other server(s)?

Thx..

Will ask the client if they are willing to share the log of connectivity to other servers. Meanwhile as a test I also switched the FTP server from Pure-ftpd to proftpd, but still the same error while connecting using http proxy.