The copy tftp flash command enables a router to copy an IOS image (the router operating system) to a router from a TFTP server. One router can act as a TFTP server to the other in this process.
The following example illustrates the steps to copy an image from Router A to Router B:
* Verify the connectivity between Router A and Router B using the ping command.
* Check the image size on both of the routers with the show flash command to verify that enough space exists on Router B.
* Configure Router A as the TFTP server using the configure terminal command. Use the

tftp-server flash [partition-number:]filename1 [alias filename2][accesslist-number]

command to define the path to system image that needs to transferred. There can be multiple entries for multiple images.
* Copy the image from Router A to Router B using the copy tftp flash command.
* Verify the flash for the copied new image on Router B with the show flash command.

The copy flash tftp command is used to copy an IOS image from the router to a TFTP server.

The copy running-config tftp command is used to copy the active or running configuration file from RAM to a TFTP server.

The copy running-config startup-config command copies the active or running configuration from RAM to NVRAM. This command creates the configuration file that will be used as the startup configuration at reboot. This should always be done after making changes to the router so that the changes are saved when the router is rebooted.

The copy tftp running-config command merges a backup configuration with the currently active running configuration in RAM.