3Com S7902E, Руководство по настройке

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2-2
Before using TFTP, the administrator needs to configure IP addresses for the TFTP client and server,
and make sure that there is a reachable route between the TFTP client and server.
When the device serves as the TFTP client, you need to perform the following configuration:
Table 2-1 Configuration when the device serves as the TFTP client
Device Configuration Remarks
Device (TFTP client)
z
Configure the IP address and routing function,
and ensure that the route between the device
and the TFTP server is available.
z
Use the tftp command to establish a connection
to the remote TFTP server to upload/download
files to/from the TFTP server
—
PC (TFTP server)
Enable TFTP server on the PC, and configure the
TFTP working directory.
—
Configuring the TFTP Client
When a device acts as a TFTP client, you can upload a file on the device to a TFTP server and
download a file from the TFTP server to the local device. You can use either of the following ways to
download a file:
z
Normal download: The device writes the obtained file to the storage medium directly. In this way, if
you use a filename that exists in the directory, the original system file will be overwritten and if file
download fails (for example, due to network disconnection), the device cannot start up normally
because the original system file has been deleted.
z
Secure download: The device saves the obtained file to its memory and does not write it to the
storage medium until the whole file is obtained. In this way, if file download fails (for example, due
to network disconnection), the device can still start up because the original system file is not
overwritten. This mode is more secure but consumes more memory.
You are recommended to use the secure mode or, if you use the normal mode, specify a filename not
existing in the current directory as the target filename when downloading the startup file or the startup
configuration file.
Source address binding means to configure an IP address on a stable interface such as a loopback
interface, and then use this IP address as the source IP address of a TFTP connection. The source
address binding function simplifies the configuration of ACL rules and security policies. You just need to
specify the source or destination address argument in an ACL rule as this address to filter inbound and
outbound packets on the device, ignoring the difference between interface IP addresses as well as the
affect of interface statuses. You can configure the source address by configuring the source interface or
source IP address. The primary IP address configured on the source interface is the source address of
the transmitted packets. The source address of the transmitted packets is selected following these
rules:
z
If no source address of the TFTP client is specified, a device uses the IP address of the interface
determined by the matched route as the source IP address to communicate with a TFTP server.
z
If the source address is specified with the tftp client source or tftp command, this source address
is adopted.