|  | 7.3 | IOS Naming and Software Image Backup
| 7.3.3 | The copy tftp flash command
After you have a backup copy of the current Cisco IOS software image, you can load a new image. You download the new image from the TFTP server by using the command copy tftp flash. The example shows that this command begins by requesting the IP address of the remote host that will act as the TFTP server. Next, the prompt asks for the file name of the new IOS image. You need to enter the correct filename of the update image as it is named on the TFTP server. Following an opportunity to confirm your entries, the procedure asks if you are willing to erase Flash memory. This makes room for the new image. Often, there is insufficient Flash memory for more than a single Cisco IOS image. You have the option of erasing the existing Flash memory before writing onto it. If no free Flash memory space is available, or if the Flash memory has never been written to, the erase routine is usually required before new files can be copied. The system informs you of these conditions and prompts you for a response. Note that the Flash memory is erased at the factory before shipment. Each exclamation point (!) means that one User Datagram Protocol (UDP) segment has successfully transferred. The series of Vs indicates successful checksum verification of a segment. Use the show flash command to view the file information and to compare its size with that of the original on the server before changing the boot system commands to use the updated image. Following a successful load, the reload command reboots the router using the updated image.