This is used for backing up the IOS of routers. The commands to configure a router are often complex and tedious – so it is recommended to keep a safe copy of them.
To create a TFTP server (cause a router to act as a tftp server):
tftp-server flash
Each router can save their IOS as a file by sending it to the server using TFTP (Trivial FTP), which is a simplistic form of FTP. Type “show version” to see what file is currently being used to store the IOS – they typically end with a .bin extension. To back up your IOS to the TFPT server, for example :
copy flash tftp (prompts you for TFTP server IP address and file names)
To restore your IOS from the TFTP server :
copy tftp flash (you will be prompted to enter the file name)