When using Passive FTP, is it possible that the port number specified by the server could be altered in any way?
For instance, if I see in the logs on my server the following, is it possible that the server actually supplied a value other than that recorded? (Note, the IP has been removed to keep anonymous)
227 Entering Passive Mode (xxx,xxx,xxx,xxx,19,181)
Unless I'm reading this incorrectly, the server in question has stated that port 5045 is to be used ((19*256)+181)
I'm currently in an argument with a Cloud Storage hosting company - who I won't name, because that is not fair on them.
They say their passive FTP port range is the Microsoft "standard" of 1025-5000... but the logs on my server (dealing with regular backups, and quotes above in the example) show that the port regularly exceeds the 5000 limit.
They adamantly deny that their server is set up for anything outside of that standard range.
What I need to know is whether my log files are actual evidence that ports are being specified outside of their stated range - or whether the server hosting company (where the cloud servers I'm running are sending information via FTP) could have any effect on it?
The company that is hosting the cloud-server that our applications run on have confirmed that there is nothing at their end that would be changing the port.
I still believe the range of ports that the FTP server is configured for exceeds the 5000 limit they state... but I have no way of proving it.
The system is currently operational, and working as I need it to - thanks to the host company opening a larger range of outbound ports.
I would still be interested to know what options (if there are others to the ones listed by @Steffan) could possibly effect the port number. But this is more for interest than to fix an urgent problem.