3 ftp/tftp upgrade -31, 3 ftp/tftp upgrade – QTECH QSW-2800 Инструкция по настройке User Manual

Page 45

Advertising
background image

+7(495) 797-3311 www.qtech.ru
Москва, Новозаводская ул., 18, стр. 1

31

Used to list existing files in the FLASH.

[Boot]: dir

boot.rom 327,440 1900-01-01 00:00:00 --SH

boot.conf 83 1900-01-01 00:00:00 --SH

nos.img 2,431,631 1980-01-01 00:21:34 ----

startup-config 2,922 1980-01-01 00:09:14 ----

temp.img 2,431,631 1980-01-01 00:00:32 ----

2. CONFIG RUN command

Used to set the IMAGE file to run upon system start-up, and the configuration file to run upon

configuration recovery.

[Boot]: config run

Boot File: [nos.img] nos.img

Config File: [boot.conf]

2.5.3 FTP/TFTP Upgrade

2.5.3.1 Introduction to FTP/TFTP

FTP(File Transfer Protocol)/TFTP(Trivial File Transfer Protocol) are both file transfer protocols

that belonging to fourth layer(application layer) of the TCP/IP protocol stack, used for

transferring files between hosts, hosts and switches. Both of them transfer files in a client-

server model. Their differences are listed below.

FTP builds upon TCP to provide reliable connection-oriented data stream transfer service.

However, it does not provide file access authorization and uses simple authentication

mechanism (transfers username and password in plain text for authentication). When using

FTP to transfer files, two connections need to be established between the client and the

server: a management connection and a data connection. A transfer request should be sent by

the FTP client to establish management connection on port 21 in the server, and negotiate a

data connection through the management connection.

There are two types of data connections: active connection and passive connection.

In active connection, the client transmits its address and port number for data transmission to

the server, the management connection maintains until data transfer is complete. Then, using

the address and port number provided by the client, the server establishes data connection on

port 20 (if not engaged) to transfer data; if port 20 is engaged, the server automatically

generates some other port number to establish data 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

Advertising