Error Message:

LIST
425 Unable to build data connection: Connection timed out
PASV
227 Entering Passive Mode (xx,xx,xx,xx,xx,xxx).
connecting data channel to xx.xxx.xx.xxx:54963

The above error message is received while you Ftp to an account successfully but it does not list the files and directories within it. The reason for the error message is, the kernel modules that are required for Ftp “i.e. to keep track of every Ftp connection and carry out the data transfer of it on another port” is not loaded.

The modules are “ip_conntrack” and “ip_conntrack_ftp” which has to be loaded using the ‘modprobe’ command.

SSH to your server as user root and execute the following commands:

# /sbin/modprobe ip_conntrack
# /sbin/modprobe ip_conntrack_ftp

To verify if the modules are loaded properly, execute

# lsmod | grep ftp

This should list the modules you just loaded. Once they appear, ftp should list the files/directories on successful login.