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Cisco ONS 15530 Configuration Guide and Command Reference
78-14227-01, Cisco IOS Release 12.1(10)EV2
Chapter3 Initial Configuration
About the Software Configuration Register
Table 3 -7 describes the values for the boot field.
Default System Boot Behavior
The factory default value for the configuration register on the Cisco ONS 15530 is 0x2102. When the
system boots, the following occurs:
•The system attempts to load the system images specified in the boot system commands in the startup
configuration file. If no boot system commands are configured, the system attempts to load the first
system image stored on the Flash memory device in slot 0.
•The console Break key sequence, or break signal, is disabled and the sy stem i gno res i t while
rebooting.
Note Regardless of the setting of the break enable bit, a break causes a return to the ROMMON
during the first few seconds (approximately five seconds) of booting.
•After five failed attempts to load a system image on the Flash memory device in slot0, the system
loads the first system image from Flash memory. If that attempt fails, the system stays in ROMMON
mode.
Boot Command
You can enter only the boot command, or you can include additional boot instructions, such as the name
of a file stored in Flash memory or a file that you specify for boot ing fr om a n etwork ser ver.
If you use the boot command without specifying a file or any other boot i nstruc tions, the sy stem boo ts
using the default system image (the first system image in onboard Flash memory). Otherwise, you can
instruct the system to boot from a specific system image in Flash memory (using the boot filename
command) or by sending a direct TFTP request to a specific server (using the boot filename ip-address
command).
For more information on system booting, see Chapter 10, “Managing Your Cisco ONS15530 System.”
Table3-7 Configuration Register Boot Field Values
Boot Field Value Description
0x0 (0-0-0-0) Stays at the system bootstrap prompt. You must boot the operating
system manually by giving a boot command to the ROMMON system
bootstrap environment.
0x1 (0-0-0-1) Boots the first system image in onboard Flash SIMM. If t he boot fails,
the system stops booting and remains in ROMMON mode.
0x2 (0-0-1-0) to 0xF (1-1-1-1) Loads the system image specified by boot system commands in the
startup configuration file. When the startup configuration file does not
contain boot system commands, the system tries to load the first
system image stored on the Flash memory device in slot 0. If that
attempt fails, the system tries to boot with the first system image in
bootflash. If that also fails, the system stops booting and remains in
ROMMON mode.
The factory default is 0x2.