In Cisco IOS, which command copies the Cisco IOS image from flash memory to a TFTP server for backup?

Introduction / Context:
Backing up the Cisco IOS image from a router or switch to a TFTP server is a basic but important administrative task. Storing a copy of the IOS image externally allows you to recover the device quickly if flash memory fails or if you need to reinstall the same version after testing upgrades. Knowing the correct copy command and the direction of the transfer is essential.

Given Data / Assumptions:

• The router currently has a working IOS image stored in flash memory.
• A TFTP server is reachable from the router and configured to receive files.
• You want to copy the IOS image from flash to the TFTP server as a backup.
• You know that the copy command has the general form copy source destination.

Concept / Approach:
The IOS copy command is used for many different file operations. To back up an IOS image, flash is the source and the TFTP server is the destination. Therefore the correct syntax is copy flash tftp. This command instructs IOS to read the specified image file from flash memory and write it to the TFTP server. Commands that reverse the order, such as copy tftp flash, are used instead when loading a new image from a TFTP server into flash.

Step-by-Step Solution:
Step 1: From the privileged EXEC prompt, enter the command copy flash tftp.Step 2: IOS prompts you to confirm the source file name, usually the current IOS image filename displayed by show flash.Step 3: Next, IOS asks for the IP address of the TFTP server where the file will be stored.Step 4: You may be prompted for a destination filename on the TFTP server; accept the default or provide a descriptive name.Step 5: IOS reads the image from flash and transfers it to the TFTP server. When complete, the router reports the number of bytes copied.

Verification / Alternative check:
After the transfer, you can verify the backup by checking the TFTP server files. Many TFTP servers display a log of received files. You can also attempt a test transfer back to a lab router or use a checksum comparison if available to confirm the integrity of the backup image.

Why Other Options Are Wrong:
Option B, copy tftp flash, does the opposite operation and is used for installing an image from TFTP onto the router.Option C, copy running-config tftp, backs up the running configuration, not the IOS image.Option D, copy startup-config flash, would copy the startup configuration to flash, which is not the goal here.Option E, copy ios tftp, uses an incorrect keyword; the correct source is flash, not ios.

Common Pitfalls:
Engineers sometimes confuse the direction of the copy command and accidentally overwrite flash or fail to back up the image at all. Always double check which device is the source and which is the destination, and verify that there is enough network connectivity and TFTP server space before starting the transfer.

Final Answer:
The correct command to back up the IOS image to a TFTP server is copy flash tftp.