When the system executes the boot.ldr file, the initialization parameters from the BOF are processed. Three locations can be configured for the system to search for the files that contain the runtime image. The locations can be local or remote. The first location searched is the primary image location. If not found, the secondary image location is searched, and lastly, the tertiary image location is searched.
If the files cannot be found or loaded, the system enters a console message dialog session prompting the user to enter alternate file locations and filenames.
When the runtime image is successfully loaded, control is passed from the bootstrap loader to the image. Depending on the options in the BOF file, the runtime image loads the configuration in one of two ways.
If ADP is enabled, no configuration files are processed at startup. Instead, ADP discovers the node configuration from the network and the primary-config file is generated based on the configuration discovered by ADP. Any existing primary-config file is backed up, then overwritten.
If ADP is not enabled, the runtime image attempts to locate the configuration file as configured in the BOF. Like the runtime image, three locations can be configured for the system to search for the configuration file. The locations can be local or remote. The first location searched is the primary configuration location. If not found, the secondary configuration location is searched, and lastly, the tertiary configuration location is searched.
The configuration file includes chassis, CSM, adapter card and port configurations, as well as system, routing, and service configurations.
Figure: System Initialization - Part 2 displays the boot sequence.
Figure: System Initialization With ADP shows the boot sequence if Automatic Discovery Protocol (ADP) is run on the system.
