Hello
For some time now I've been running into an issue where FTP connections are being dropped going to one of our Azure VM's. The issue is similar, but not identical to a few issues posted back in 2011/2012 linked to load balancer timeouts. Oddly though, the test system works flawlessly, however on our live system, we are often receiving "data connection closed" messages back from the server and the FTP transfer collapses. This behaviour is duplicable with both FileZilla Server and IIS FTP too, to confound the problem further.
It's not totally similar though. Some of the files which seem to transfer fine are 100's of MB while often smaller ~1kb XML files will fail.
After reconfiguring both Test and Live to use passive mode (and opened ports through the Azure Endpoint Mapper) I threw ~250 files at both systems to see how stable it would be. Test worked flawlessly (of course) but Live started falling over after ~50 files then died completely.
Any ideas why one would work and another wouldn't ?