What is the difference between passive and active FTP?

Which two statements describe the FTP protocol?

The FTP client initiates the transfer of data when using a passive data connection. It requires two connections between client and server.

Why might you have problems connecting to an FTP server PORT mode?

Check the server has passive ftp enabled.

Which operating mode is generally necessary when running an FTP client behind a firewall?

PASV ("passive mode") is necessary when running a FTP client behind a firewall, as the default ("active mode") method will fail since the FTP server is unable to open a client to the client, usually because of NAT or firewall limitations.

What is FTP moves files between devices?

FTP, or File Transfer Protocol, is a standard network protocol used to transfer files between a client and a server over a TCP/IP network. It allows users to upload, download, and manage files on remote servers, facilitating data exchange across different devices. FTP operates in two modes: active and passive, which determine how the connection is established between the client and server. Despite its utility, FTP is often considered less secure than other protocols, such as SFTP or FTPS, because it transmits data in plain text.

How do you run an FTP client behind a firewall?

To run an FTP client behind a firewall, you typically need to ensure that the necessary ports for FTP are open. FTP uses port 21 for commands, and for passive mode, it may require a range of high-numbered ports (usually between 1024 and 65535) for data transfer. Configure the firewall to allow these ports, or set the FTP client to use passive mode, which is often more firewall-friendly. Additionally, consider using secure FTP variants, like FTPS or SFTP, which can help manage connections through firewalls more effectively.

Which network protocol uses port 21?

The network protocol that uses port 21 is FTP (File Transfer Protocol). FTP is commonly used for transferring files between a client and a server on a computer network. Port 21 is specifically designated for FTP control connections. When a user initiates an FTP connection, the client connects to the server's port 21 to establish communication for sending and receiving files. It is important to note that FTP operates in two modes: active mode and passive mode, each using different ports for data transfer.

Which two TCP ports does FTP use?

FTP (File Transfer Protocol) uses two TCP ports: port 21 and port 20. Port 21 is used for command control, where commands and responses are exchanged between the client and server. Port 20 is used for data transfer in active mode, where the server connects to the client to send the requested data. In passive mode, data is transferred over a dynamically assigned port above 1024.

Which protocols does FTP use?

FTP (File Transfer Protocol) primarily uses two protocols: TCP (Transmission Control Protocol) for reliable data transfer and control commands. It typically operates over two separate channels: the command channel on port 21 for sending commands and the data channel, which can use a dynamic port for transferring files. Additionally, FTP can operate in two modes—active and passive—which determine how the data connection is established.

How do you use a FTP client on a WiFi network?

There is no difference with FTP as a client on either a wired or wireless network; you use it the same way.

Explain the purpose of the file transfer protocol?

File Transfer Protocol (FTP) is used for transferring files between an FTP client and an FTP server.

What company offers the best free FTP client?

FTP clients are programs that enable large file transfers between servers and computers. Some good options for a free FTP client are Fire FTP, Cyberduck, and Core FTP LE.

What ports need to be open for the client to use the FTP client software?

FTP is a TCP based service exclusively. There is no UDP component to 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. In active mode FTP the client connects from a random unprivileged port (N > 1023) to the FTP server's command port, port 21. Then, the client starts listening to port N+1 and sends the FTP command PORT N+1 to the FTP server. The server will then connect back to the client's specified data port from its local data port, which is port 20. From the server-side firewall's standpoint, to support active mode FTP the following communication channels need to be opened: * FTP server's port 21 from anywhere (Client initiates connection) * FTP server's port 21 to ports > 1023 (Server responds to client's control port) * FTP server's port 20 to ports > 1023 (Server initiates data connection to client's data port) * FTP server's port 20 from ports > 1023 (Client sends ACKs to server's data port) In order to resolve the issue of the server initiating the connection to the client a different method for FTP connections was developed. This was known as passive mode, or PASV, after the command used by the client to tell the server it is in passive mode. In passive mode FTP the client initiates both connections to the server, solving the problem of firewalls filtering the incoming data port connection to the client from the server. When opening an FTP connection, the client opens two random unprivileged ports locally (N > 1023 and N+1). The first port contacts the server on port 21, but instead of then issuing a PORT command and allowing the server to connect back to its data port, the client will issue the PASV command. The result of this is that the server then opens a random unprivileged port (P > 1023) and sends the PORT P command back to the client. The client then initiates the connection from port N+1 to port P on the server to transfer data. From the server-side firewall's standpoint, to support passive mode FTP the following communication channels need to be opened: * FTP server's port 21 from anywhere (Client initiates connection) * FTP server's port 21 to ports > 1023 (Server responds to client's control port) * FTP server's ports > 1023 from anywhere (Client initiates data connection to random port specified by server) * FTP server's ports > 1023 to remote ports > 1023 (Server sends ACKs (and data) to client's data port)