Q. I'm using ProFTPD FTP server under CentOS Linux. How do I make sure that my FTP client does not disconnect or timeout connection to FTP server?
A. Most ftp client can ping to FTP server to stay connected but some client cannot do this. However, you can increase timeout on server itself.
The TimeoutNoTransfer directive configures the maximum number of seconds a client is allowed to spend connected, after authentication, without issuing a command which results in creating an active or passive data connection (i.e. sending/receiving a file, or receiving a directory listing).
Open your /etc/proftpd.conf file, enter:
# vi /etc/proftpd.conf
Set TimeoutNoTransfer to 1200 from default 300:
# service proftpd restart
See ProFTPD tutorial for more information.