System information

Troubleshooting Booting Problems
Book Title
3-54
Booting: Router Is Stuck in ROM Monitor Mode
Symptom: Router is stuck in ROM monitor mode. When a user is booting a router from ROM, the
system boots into ROM monitor mode but does not boot the complete system image.
Table 3-20 outlines the problems that might cause this symptom and describes solutions to those
problems.
Table 3-20 Booting: Router Is Stuck in ROM Monitor Mode
Booting: Scrambled Output When Booting from ROM
Symptom: When a user is booting from ROM, the router displays indecipherable text output on the
console.
Table 3-21 outlines the problems that might cause this symptom and describes solutions to those
problems.
Table 3-21 Booting: Scrambled Output When Booting from ROM
Possible Problem Solution
Incorrect configuration
register setting
Step 1 At the ROM monitor prompt (>), enter b to boot the system.
Step 2 If a configuration exists in NVRAM, the system displays the vacant
message. Press the Enter key to continue.
If a configuration does not exist in NVRAM, the setup menu appears.
Skip the setup process.
Step 3 Use the show version exec command to determine the configuration
register setting.
Step 4 Look for an invalid configuration register setting. The default is 0x101,
which disables the Break key and forces the router to boot from ROM.
A typical “bad” setting has a 0 in the least significant bit (for example
0x100).
For details about setting the configuration register, refer to your
hardware installation and maintenance publication.
Break key pressed during boot
process
At the ROM monitor prompt, enter c to allow the router to continue booting.
Console cable inserted or removed
during boot process, or console
power-cycled during boot process
Step 1 Press the Enter key and wait for the ROM monitor prompt (>).
Step 2 If the ROM monitor prompt appears, enter c at the prompt to continue
the booting process.
Possible Problem Solution
Wrong terminal
speed setting
Step 1 Use the monitor setup menu to check the terminal line speed setting for the monitor.
Step 2 Check the terminal speed configured on the router as specified in the configuration
register setting (default is 9600 baud, 8 databits, 2 stop bits, and no parity).
Step 3 If the terminal speed of the monitor and the router do not match, modify as necessary.
Refer to your hardware installation and maintenance documentation for details about
setting up the monitor.