KB.15.15

Figure 135 Example of message for download failure

Some of the causes of download failures include:

• Incorrect or unreachable address specified for the TFTP Server parameter. This may include

network problems.

• Incorrect VLAN.

• Incorrect name specified for the Remote File Name parameter, or the specified file cannot be

found on the TFTP server. This can also occur if the TFTP server is a UNIX machine and the

case (upper or lower) for the filename on the server does not match the case for the filename

entered for the Remote File Name parameter in the Download OS (Operating System, or

software) screen.

• One or more of the switch's IP configuration parameters are incorrect.

• For a UNIX TFTP server, the file permissions for the software file do not allow the file to be

copied.

• Another console session (through either a direct connection to a terminal device or through

Telnet) was already running when you started the session in which the download was attempted.

To find more information on the cause of a download failure:

• Examine the messages in the switch's Event Log by executing the show log tftp command

from the CLI.

NOTE: If an error occurs in which normal switch operation cannot be restored, the switch

automatically reboots itself, and an appropriate message is displayed after the reboot.

Using SCP and SFTP

For some situations you may want to use a secure method to issue commands or copy files to the

switch. By opening a secure, encrypted SSH session and enabling ip ssh file transfer, you can then

use a third-party software application to take advantage of SCP and SFTP. SCP and SFTP provide

a secure alternative to TFTP for transferring information that may be sensitive (like switch

configuration files) to and from the switch. Essentially, you are creating a secure SSH tunnel as a

way to transfer files with SFTP and SCP channels.

Once you have configured your switch to enable secure file transfers with SCP and SFTP, files can

be copied to or from the switch in a secure (encrypted) environment and TFTP is no longer necessary.

To use these commands, you must install on the administrator workstation a third-party application

software client that supports the SFTP and/or SCP functions. Some examples of software that

supports SFTP and SCP are PuTTY, Open SSH, WinSCP, and SSH Secure Shell. Most of these are

freeware and may be downloaded without cost or licensing from the internet. There are differences

in the way these clients work, so be sure you also download the documentation.

292 File transfers