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connection.
In passive connection, the client, through management connection, notify the server
to establish a passive connection. The server then creates its own data listening port and
informs the client about the port, and the client establishes data connection to the
specified port.
As data connection is established through the specified address and port, there is a
third party to provide data connection service.
TFTP builds upon UDP, providing unreliable data stream transfer service with no
user authentication or permission-based file access authorization. It ensures correct data
transmission by sending and acknowledging mechanism and retransmission of time-out
packets. The advantage of TFTP over FTP is that it is a simple and low overhead file
transfer service.
ES3628EA switch can operate as either FTP/TFTP client or server. When
ES3628EA switch operates as a FTP/TFTP client, configuration files or system files can
be downloaded from the remote FTP/TFTP servers(can be hosts or other switches)
without affecting its normal operation. And file list can also be retrieved from the server in
ftp client mode. Of course, ES3628EA switch can also upload current configuration files
or system files to the remote FTP/TFTP servers(can be hosts or other switches). When
ES3628EA switch operates as a FTP/TFTP server, it can provide file upload and
download service for authorized FTP/TFTP clients, as file list service as FTP server.
Here are some terms frequently used in FTP/TFTP.
ROM:
Short for EPROM, erasable read-only memory. EPROM is repalced by FLASH
memory in ES3628EA switch.
SDRAM:
RAM memory in the switch, used for system software operation and
configuration sequence storage.
FLASH:
Flash memory used to save system file and configuration file
System file:
including system image file and boot file.
System image file:
refers to the compressed file for switch hardware driver and software
support program, usually refer to as IMAGE upgrade file. In ES3628EA switch, the
system image file is allowed to save in FLASH only. ES3628EA switch mandates the
name of system image file to be uploaded via FTP in Global Mode to be nos.img, other
IMAGE system files will be rejected.
Boot file:
refers to the file initializes the switch, also referred to as the ROM upgrade file
(Large size file can be compressed as IMAGE file). In ES3628EA switch, the boot file is
allowed to save in ROM only. ES3628EA switch mandates the name of the boot file to be
boot.rom.
Configuration file:
including start up configuration file and running configuration file. The
distinction between start up configuration file and running configuration file can facilitate
