3Com 4800G Series, Configuration Manual

Page: 991 / 1246

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FTP C
ONFIGURATION
When configuring FTP, go to these sections for information you are interested in:
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“FTP Overview” on page 991
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“Configuring the FTP Client” on page 992
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“Configuring the FTP Server” on page 996
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“Displaying and Maintaining FTP” on page 999
FTP Overview
Introduction to FTP The File Transfer Protocol (FTP) is an application layer protocol for sharing files
between server and client over a TCP/IP network.
FTP uses TCP ports 20 and 21 for file transfer. Port 20 is used to transmit data, and
port 21 to transmit control commands. Refer to RFC 959 for details of FTP basic
operation.
FTP transmits files in two modes:
■
Binary mode for program file transmission
■
ASCII mode for text file transmission
Implementation of FTP FTP adopts the server/client model. Your switch can function either as client or as
server (as shown in Figure 297). They work in the following way:
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When the switch serves as the FTP client, a PC user first telnets or connects to
the switch through an emulation program, then executes the
ftp command to
establish the connection to the remote FTP server, and gain access to the files
on the server. If the remote FTP server supports anonymous FTP, the device can
log onto it directly; if not, the device must obtain FTP username and password
first to log onto the remote FTP server.
■
When the switch serves as the FTP server, it must be configured with an IP
address so that a user running FTP client program can access it. For the sake of
security, the switch does not support anonymous FTP. Therefore, you must use
an authenticated username and password. By default, authenticated users can
access the root directory of the switch.
Figure 297 Network diagram for FTP
Switch
IP network
PC