You can use the show version command to verify and troubleshoot some of the basic hardware and software components of the router. The command displays information about the version of the Cisco IOS software currently running on the router, the version of the bootstrap program, and information about the hardware configuration, including the amount of system memory.

The output from the show version command includes:

The last line of the show version command displays the current, configured value of the software configuration register in hexadecimal. If there is a second value displayed in parentheses, it denotes the configuration register value that is used during the next reload.

The configuration register has several uses, including password recovery. The factory default setting for the configuration register is 0x2102. This value indicates that the router attempts to load a Cisco IOS software image from flash memory and load the startup configuration file from NVRAM.