When you first bring up a Cisco router, it will run power-on self test (POST),and if that passes, It will look for and load he Cisco IOS from flash memory if a file is present. Flash memory is an electronically erasable programmable read–only memory (EEPROM).The IOS will load and then look for a valid configuration called strapup-config that is stored by default in nonvolatile RAM (NVRAM). If there is no configuration in NVRAM, then the router will bring up what is called set up mode. This is a step-by-step process to help you configure a router. You can also enter setup mode at any time from the command line by typing the command setup from global configuration mode. Setup only covers some very global commands, but is helpful if you don’t know how to configure certain protocols, like bridging or DECnet, for example.