What 2 ports are used by FTP?
FTP is an unusual service in that it utilizes two ports, a ‘data’ port and a ‘command’ port (also known as the control port). Traditionally these are port 21 for the command port and port 20 for the data port. The confusion begins however, when we find that depending on the mode, the data port is not always on port 20.
What port does FTP use by default?
port 21
FTP communications use two port number values – one for commands (port 21 by default) and one for data transfer (this is where the PORT command comes into play). The PORT command is sent by an FTP client to establish a secondary connection (address and port) for data to travel over.
Does FTP use multiple ports?
Multiple Ports, Multiple Modes. Unlike most protocols used on the Internet, FTP requires multiple network ports to work properly. When an FTP client application initiates a connection to an FTP server, it opens port 21 on the server — known as the command port. This port is used to issue all commands to the server.
Which ports are used by FTP server in active mode?
Most commonly, FTP servers use port 20 to transfer data. If it’s up to the server (Active mode) your FTP client is likely to be assigned port 20, which is blocked. You can use Passive mode to get around this — your FTP client can suggest a port for the client and server to use.
What are ports 20 and 21 used for?
The Protocol Port numbers 21 and 20 are used for FTP. Port 21 is used to establish the connection between the 2 computers (or hosts) and port 20 to transfer data (via the Data channel).
What is port 21 used for FTP?
The FTP protocol typically uses port 21 as its main means of communication. An FTP server will listen for client connections on port 21. FTP clients will then connect to the FTP server on port 21 and initiate a conversation. This main connection is called the Control Connection or Command Connection.
Why does FTP have 2 ports?
FTP is an old protocol. That’s really the only reason. The designers thought that the amount of data flowing over the data port would make it so that they couldn’t send control commands in a timely manner, so they did it as two ports.
Which FTP port should I use?
The FTP port that you generally need to know about to make a standard, unencrypted, FTP connection is port 21. For this standard case, this is all someone using an FTP client needs to know.
Why FTP uses two ports?