Understanding Configuration Files - Cisco ASR 5000 Series Administration Manual

System Operation and Configuration
The following steps describe the system's boot process:
Step 1 When power is first applied to the chassis, or after a reboot, only the MIO/UMIO/MIO2s in slot 5 and slot 6 receive
power.
Step 2
During the startup process, the MIO/UMIO/MIO2 performs a series of power-on self tests (POSTs) to ensure that its
hardware is operational.
Step 3 If the MIO/UMIO/MIO2 in slot 5 successfully executes all POSTs, it becomes the active MIO. The MIO in slot 6 becomes
the standby card. If there is a problem with the MIO in slot 5, the MIO in slot 6 becomes the active MIO.
Step 4 The active MIO/UMIO/MIO2 begins loading the operating system software image designated in the boot stack. The
boot stack entries are contained in the boot.sys file that resides on flash memory on the MIO/UMIO. The standby
MIO/UMIO/MIO2 observes the active card startup. If the file on the active MIO/UMIO/MIO2 is loads normally, the
standby MIO/UMIO boots from the active card image. If the active MIO/UMIO experiences problems during this phase,
the standby MIO/UMIO/MIO2 loads its software image designated by its own boot stack entry in its boot.sys file and
takes over control of the system as the active MIO/UMIO/MIO2.
Step 5 After the software image is loaded into its memory, the active MIO/UMIO/MIO2 determines whether other cards are
installed in the chassis by applying power to the other chassis slots and signalling them. If the chassis slot contains a
card, power is left On to that slot. All empty slots are powered off.
If no MIOs are installed or if both fail to boot successfully, no other card installed in the system will boot.
Step 6 When power is applied to the DPC/UDPCs or DPC2/UDPC2s installed in the system, they each perform their own series
of POSTs.
Step 7 After successful POST, each DPC/UDPC or DPC2/UDPC2 enters standby mode.
Step 8
After entering the standby mode, each of the control processors (CPs) on the DPC/UDPCs or DPC2/UDPC2s communicate
with the active MIO/UMIO/MIO2 to receive the appropriate code.
Step 9 Upon successful loading of the software image, the system loads a configuration file designated in the boot stack (boot.sys
file). If this is the first time the system is powered on and there is no configuration file, the active MIO/UMIO/MIO2
invokes the system's Quick Setup wizard. Use the Quick Setup wizard to configure basic system parameters for
communication across the management network.
The wizard creates a configuration file (system.cfg) that you can use as a starting point for subsequent configurations.
This allows you to configure the system automatically by applying the configuration file during any subsequent boot.
For additional information about system configuration files, refer to the Understanding Configuration Files section.

Understanding Configuration Files

The system supports the use of a file or script to modify configurable parameters. Using a file for offline
system configuration reduces the time it takes to configure parameters on multiple systems.
A system configuration file is an ASCII text file that contains commands and configuration parameters. When
you apply the configuration file, the system parses through the file line-by-line, testing the syntax and executing
the command. If the syntax is incorrect, a message is displayed to the CLI and the system proceeds to the next
command. Lines that begin with # are considered remarks and are ignored.
Understanding Configuration Files
ASR 5500 System Administration Guide, StarOS Release 21.4
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