I've just run into a puzzling problem involving anonymous downloads from my proftpd server. Up until tonight it had been working exactly as expected, to send files to my clients when the files were much too large for attaching to Email (15 to 21 MB per file, zipped).
Tonight, however, I made a 39-MB file available to a client, and he was unable to download it although during the same session he WAS able to download a 21-MB one. The extended log shows that the successful download sent this sequence of commands: "PASV, TYPE I, SIZE, MDTM, RETR" and all worked perfectly. The failing attempts would send "PASV" and then lock up at that point despite getting the identical 227 response from the server.
After several attempts, I had the client download and install the WS_FTP Pro client evaluation version. With it he was able to get through the entire sequence and issue the RETR for the file -- which promptly got a 550 response! He's apparently still waiting, 50 minutes later, for the transfer to do something, but my modem lights indicate no activity.
The file in question has exactly the same permissions and ownership as does the 21-MB file that downloaded successfully. I'm stymied to figure out what's causing the problem -- especially since I was able to "download" the file using my own copy of WS_FTP Pro (but the switch lights indicated that the action all took place on my LAN even though it used the external IP of my server).
The proftpd docs indicate that there's no default for "quotas" which can be set either "on" or "off." To me such a boolean switch MUST have a default. Could it be that quotas defaults to "on" despite the documentation and uses some unknown value between 21 and 39 MB? Any ideas will be welcomed...
