Maxwillian Miorim a écrit :
FTP traffic pass through ports 20 UDP and 21 TCP. First one "head" is established with an connection in UDP port 20, after this all traffic is exchanged through port 21 TCP.
Nonsense.The FTP protocol uses only TCP, not use UDP. 21/TCP is the destination port for the client -> server control connection. 20/TCP is the source port in active mode for the server -> client data transfer connections. 20/TCP is not used in passive mode.