“…As can be seen from Figure 3, FTP makes it possible to share data files between service hosts and between servers and clients, which is essentially copying files back and forth between two hosts [13]. e basic process of FTP is firstly, establishing a connection, secondly, transferring data and releasing data, and finally, releasing the connection [14]. Observing Figure 3, we can see that there are two types of connections in FTP mode, namely data connection and control connection, so there are two ports between FTP server and client, one for transferring commands and one for transferring data.…”