FTP Usage FAQ

1. What is FTP (File Transfer Protocol)

File TRANSFER PROTOCOL (FTP) is a document transfer protocol that manages file transfer between computers. FTP is usually referred to as a file transfer service.

FTP is a very extensive communication protocol used on the Internet. It is a collection of rules that support Internet file transfers that enable Internet users to copy files from one host to another, thereby providing users with great convenience and benefits. FTP also usually indicates the application that the user uses to execute the protocol (for example, "fooled") to obtain the required information.

FTP, like other internet services, is a client/server approach. Using the method is simple, starting the FTP client establishes a connection to the remote host, and then sends a transfer command to the remote host, which responds when the command is received and executes the correct command. FTP has a fundamental limitation, that is, if the user is not authorized by an FTP host, can not access the host, in fact, users can not log on remotely (remote login) into the host. That is, if the user is not registered on a host to obtain authorization, without a username and password, it cannot be transmitted to the host file. However, anonymous FTP (anonymous FTP) cancels this restriction.

2. What is anonymous FTP (anonymous file transfer)

Anonymous (anonymous file transfer) enables a user to connect to a remote host and copy files from a remote host anonymously, without having to be a registered user of that remote host. Users with special username "Anonymous" and "guest" can have restricted access to the files exposed on the remote host. Many systems now require users to use the EMAI1 address as a password to better align access. For security purposes, most anonymous FTP hosts allow only remote users to download (download) files instead of uploading (upload) files. That is, users can only copy the required files from an anonymous FTP host and cannot copy files to an anonymous FTP host. In addition, the anonymous FTP host also uses some other protection to protect its own files from being modified and deleted by the user, and to prevent the intrusion of computer viruses. Before the World Wide Web environment with a graphical user interface began to become popular in 1995, anonymous FTP was the primary way to access information resources on the Internet, storing countless files in thousands of anonymous PTP hosts on the internet, These files contain a wide variety of information, data, and software. People can use anonymous FTP when they know the host address of specific information resources, but anonymous FTP is still a basic method of transmitting and distributing software on the Internet.

3. What is remote login (remote login)

Remote login (telnet) refers to a user logging on to a remote host over the Internet. After this connection is established, the user's calculation can be used as a terminal for a remote host. Telnet is the primary way to telnet on the Internet, and anonymous FTP requires that you first log on remotely to make file transfers.

4. What is upload (upload)

Upload (uploading) refers to uploading data from a local computer to a remote host, which is tightly managed and controlled, but Upload is the basis for submitting user information and requirements for remote interactive applications.

5. What is an FTP connection

FTP connection to the first to give the purpose of the FTP server name or address, when connected to the FTP server, the general to log in, after verifying the user ID number and password, the connection can be established, some systems also allow users to login anonymously. As in all multiuser systems, different users have different permissions for the same directory or file, so if they find it impossible to download or upload certain files during use, it is generally due to insufficient user rights.

6.FTP File Transfer Mode

FTP can transfer files in a variety of formats, usually determined by the system, and most systems (including UNIX systems) have only two modes: Text mode (ASCII) and binary mode (bin/image).

The text transmitter uses ASCII characters and is separated by a return key and a newline character, while the binary mode is faster than text mode and can transmit all ASCII values, so the system administrator typically sets FTP to binary mode without converting or formatting. Note that you must ensure that the correct transfer mode is used before transferring files using FIP, and that the binary files in text mode will cause errors.

7.FTP Reliability Problem

FTP is based on the Transport Layer TCP protocol, TCP is a connection-oriented protocol, responsible for ensuring data from the source computer to the destination computer transmission. TCP uses a series of measures such as checksum, acknowledgement and timeout retransmission to provide reliable transmission, so the FTP program does not need to worry about transmission if there is no prompt error in the transmission process.