Basic Enumeration
Attempt to connect anonymously by issuing the below command and specifying the following credentials; anonymous:anonymous.
ftp <ipAddress>
You can perform banner grabbing w/ the following Metasploit module.
use auxiliary/scanner/ftp/ftp_version
You can perform brute force with the following Metasploit module.
use auxiliary/scanner/ftp/ftp_login
Transferring Files
If you have valid credentials, you can use the following command to download all files recursively.
wget --mirror 'ftp://<username>:<password>@<ipAddress>