I implemented ftp servers on Azure platform - Window Server 2012 following http://www.intstrings.com/ramivemula/articles/enable-ftp-access-on-windows-azure-vm/ link. In summary, I created ports (2500-2504) and used them for FTP services. In same time, I created dataport (1000-1005) and registered them through azure port as endpoints.
I created App Service under Azure Platform. While I debug (FtpWebRequest command - Download, Upload & ListDirectoryDetails) this app service in my workstation, it works fine. But this app service program is sometimes throwing error when it's in Azure platform. It returns "The remote server returned an error: (425) Can't open data connection." error.
Any idea? Thanks you in advance.