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The Illustrated Network- P57

The Illustrated Network- P57:In this chapter, you will learn about the protocol stack used on the global public Internet and how these protocols have been evolving in today’s world. We’ll review some key basic defi nitions and see the network used to illustrate all of the examples in this book, as well as the packet content, the role that hosts and routers play on the network, and how graphic user and command line interfaces (GUI and CLI, respectively) both are used to interact with devices. | CHAPTER 20 File Transfer Protocol 529 Table 20.5 FTP Commands for Transfer Parameters with Meaning and Parameters Command Meaning Parameter s TYPE Identify the file type for transfer A ASCII E EBCDIC I binary image N nonprint T telnet C ASA STRU File structure F file or R record MODE Format used for transmission S stream B block C compressed Table 20.6 FTP Commands for File Transfer with Meaning and Parameters Command Meaning Parameter s ALLO Allocate enough space for the data to come Integer number of bytes APPE Append a local file to the remote file File names EPSV The extended version RFC 2428 of the PASV command used for IPv6 and NAT IP address and port EPRT The extended version RFC 2428 of the PORT command used for IPv6 and NAT IP address and port PASV Supply the network address and port number that will be used for the data connection initiated by the client IP address and port PORT Supply the network address and port number that will be used for the data connection initiated by the server IP address and port REST Identify a restart marker followed by the transfer command to be restarted Marker value RETR Get retrieve a file File name s STOR Put store a file File name s STOU Create a version of the file with a unique name store unique File name The three FTP commands that set the type structure and mode of the file transfer are outlined in Table 20.5. The 10 FTP commands that actually control the file transfer are outlined in Table 20.6. Finally the five FTP commands outlined in Table 20.7 supply useful information to the user. Variations on a Theme Few people use the command line interface for FTP unless they have to. However it is common to use the CLI for instructional purposes as done here . But today almost all FTP client software and many servers use GUI interfaces to let users simply point and 530 PART IV Application Level Table 20.7 FTP Commands for User Information with Meaning and Parameters Command Meaning Parameter s HELP Gives information about .