Chapter 4 System Startup and Basic System Configuration
Configuring the Software Configuration Register
•Read boot system commands from the configuration file stored in NVRAM. Table
Caution To avoid confusion and possibly halting the system, remember that valid software configuration register values may be combinations of settings, rather than the individual settings listed in Table
Table
Bit Number | Hexadecimal Value | Meaning/Function |
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00 to 03 | 0x0000 to 0x000F | Comprises the boot field for defining |
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| the source of a default Cisco IOS |
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| software image required to run the |
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| router (see Table |
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06 | 0x0040 | Causes the system software to ignore |
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| the contents of NVRAM |
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07 | 0x0080 | Enables the OEM1 bit |
08 | 0x0100 | Disables the break function |
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09 | 0x0200 | Uses a secondary bootstrap |
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10 | 0x0400 | Broadcasts Internet Protocol (IP) with |
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| all zeros |
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11 and 12 | 0x0800 to 0x1000 | Defines the console baud rate (default |
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| = 9600 bps) |
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13 | 0x2000 | Boots the default flash memory |
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| software if the network boot fails |
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14 | 0x4000 | Excludes network numbers from |
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| IP broadcasts |
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15 | 0x8000 | Enables diagnostic messages and |
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| ignores the contents of NVRAM |
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1. OEM = original equipment manufacturer.
| Cisco 12010, Cisco 12410, and Cisco 12810 Router Installation and Configuration Guide |
|