Not sure what you are asking...
You need an FTP server (something like vsftp OR proftpd) on the one box (or both for transfer back and forth) and a client (almost all modern distros have a command line FTP client installed by default).
To find out if you've got an ftp server running, use ps aux from a command line:
ps aux | grep ftp
It should bring up any instance of "ftp" that you have. If something is returned, then more than likely you've got the server running.
Next is to define IP's to host names (also known as resolving or DNS). This is done in your /etc/hosts file, the entry might look something like this (depending on the names of your boxes and their IP's):
192.168.1.25 cooler.localhost cooler
192.168.1.26 cool.localhost cool
This will resolve that name to that IP so you can just type names in, then:
Will start the ftp client into cool (Cool must be running a server, see above).