Cisco IOS Maintenance — Upgrading Router IOS from a TFTP Server On a Cisco router, which command copies a new IOS image from a TFTP server into the device's flash memory to perform an upgrade?

Introduction / Context:
Keeping Cisco IOS up to date is a core administrative task. Administrators commonly stage a new image on a TFTP server and then transfer it to the router's flash memory. Knowing the exact copy syntax prevents outages and failed boots.

Given Data / Assumptions:

• The new IOS image file resides on a reachable TFTP server.
• The router has IP reachability to the TFTP host (correct interface, default gateway, and ACLs).
• Sufficient flash space exists to store the image.

Concept / Approach:
The IOS copy command follows the format copy where common sources/destinations include tftp, flash, running-config, startup-config. To upgrade IOS, you must copy from the TFTP source to the router's flash storage: copy tftp flash. After the transfer, update the boot variable and save configuration if needed, then reload to boot the new image.

Step-by-Step Solution:
Ensure IP connectivity to the TFTP server (ping).Execute: copy tftp flashEnter TFTP server IP, then the image filename when prompted.Verify with: show flash and show bootvar; set boot system if necessary.

Verification / Alternative check:
Use dir flash: or verify /md5 flash: to confirm a successful copy and integrity prior to reload.

Why Other Options Are Wrong:

• copy tftp run/start: Copies text configs into running or startup configuration, not IOS images.
• config net: Legacy configuration retrieval, not image management.
• copy running-config flash: Backs up config to flash, not an image upgrade.

Common Pitfalls:
Forgetting to set the correct boot system statement or insufficient flash space, causing the router to boot an old image or fail to boot.

Final Answer:
copy tftp flash