Router Boot Process

The Router Boot Process :

Whenever Router Boots , it takes the following steps :

1. The router is powered on.

2. The bootstrap program (Rommon) is loaded from ROM.

3. The bootstrap runs POST.

4. The bootstrap attempts to load the IOS from Flash. In this Step Following sub steps occurs :

i). If the IOS is not found in Flash, the bootstrap loads into RAM the basic IOS stored in ROM.

ii). If the IOS is found in Flash, it is loaded into RAM.

 5. The IOS attempts to load the startup-config file from NVRAM . In this Step Following sub steps occurs

i). If the startup-config is not found in NVRAM, the IOS attempts to load a configuration file from   TFTP.

ii). If no TFTP server responds, the router enters Initial Configuration Mode.

iii). If the startup-config is found in NVRAM, it is loaded into RAM.

 6. The startup-config becomes the running-config in RAM.

Now the Router is ready for  Network operations.