FTP commands over a VPN to an AS/400

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A client of ours insists on encrypting a file and sending it via FTP instead of 
emailing it.  We have never let a customer FTP into our AS/400 before.

For test purposes, I played around with running FTP commands from my home via a 
VAN to the AS/400 at work to test out how our client would get into our system. 
 I was surprised to find out that when I added or deleted a file from the 
system, there was no record or log of my activities when I was signed on via 
FTP.

Our company has to setup the VAN software on the client's PC to enable them to 
FTP to our AS/400.

Is there a way to keep track or log any kind of FTP commands or anything done 
to the system while a customer is signed on via FTP?  Or, is there a way to 
limit what a user can do while signed on via FTP?

IT,

Frank
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