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startup-config
temp.img
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]
4.5.3 FTP/TFTP Upgrade
4.5.3.1 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
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
2,922 1980-01-01 00:09:14 ----
2,431,631 1980-01-01 00:00:32 ----
4-19
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Troubleshooting
