Recently one of my clients has brought it to my attention that they are experiencing some issues with upload. What happens is when someone uploads say a 15.7 MB file, or set of files, like a scripts file structure or something, they get cut off 1/2 way through, and for instance in smart ftp client it says A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
or host closed the remote connection, or it's timed out, or others. Any ideas if there is a setting that i'm perhaps over looking?
Try opening the ports 30000 - 35000 in your firewall. Or even see whether client is able to upload without any issues without firewall.
It could be either the firewall at server side or the client side which may be causing the issue. I hope you were also able to duplicate the issue. I believe the timeouts in the ftpd configuration is not too low as well.
If you are using cPanel, did you try switching to pro-ftpd and see whether it happens with pro-ftpd as well ? Though you mentioned the issue is with pure-ftpd, I just wanted to confirm whether it is only with pure-ftpd
here is the direct output again of what is happening. It does this at the same point over and over again.
[13:37:06] Opening data connection to 18.104.22.168 Port: 52821
[13:37:06] STOR bd.png
[13:37:27] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.