The network administrator has configured the enterprise firewall to permit port 21 to allow FTP transfers to occur from outside the enterprise. Users can connect to the FTP server that is located on the enterprise network. However, file transfers fails. Why could this be

The answer is "Port 20 must be authorised, along with Port 21."

Explanation:

It could be used to transfer data all machines on a computer, as only the title suggests. It can be used to exchange information across user accounts, transfer data to the server software records.

The firewalls use network enterprise to described as stand-alone IPSec and VPN, which provide extensive gateway and control capability to secure network connections. It provides the set up for the system administrator, which enables the port 21 for FTP payments within the company.