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Cisco ONS 15530 Configuration Guide and Command Reference
78-16019-02, Cisco IOS Release 12.2(18)SV2
Chapter3 Initial Configuration
About the Software Configuration Register
Table3-7 describes the values for the boot field.
Default System Boot Behavior
The factory default value for the configuration register on the CiscoONS 15530 is 0x2102. When the
system boots, the following occurs:
•Thesystem attempts to load the system images specified in the boot system commands in the startup
configurationfile. 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 system ignores it 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 fivefailed attempts to load a system image on the Flash memory device in slot 0, the system
loads the firstsystem image from Flash memory. If that attempt fails, the system stays in ROMMON
mode.
Boot Command
Youcan 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 booting from a network server.
If you use the boot command without specifying a file or anyother boot instructions, the system boots
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 13, “Managing Your CiscoONS 15530 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 givinga boot command to the ROMMON system
bootstrap environment.
0x1 (0-0-0-1) Boots the first systemimage in onboard Flash SIMM. If the 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 byboot system commands in the
startup configurationfile. 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.