Chapter Summary
The typical boot process follows this sequence:
- First, the router checks all of its internal hardware components, during a process called the POST (power-on self-test).
- Next, the router loads the basic configuration routine known as the bootstrap program.
- Then, the bootstrap attempts to locate the Cisco IOS, which in turn loads the router configuration file.
- If the Cisco IOS is set to load from a TFTP server, but the TFTP server cannot be located, then the IOS will boot from flash memory.
- If the IOS cannot be found in flash memory or on the TFTP server, then a limited version will boot from ROM.
- If the Cisco IOS is set to load a configuration file from a TFTP server, but the file or server is not available, the configuration file will be loaded from NVRAM. However, if a configuration file is not available in NVRAM or on a TFTP server, then the automated setup routine will be initialized.