Difficulty: Easy
Correct Answer: Tells the router to look in NVRAM for the boot sequence
Explanation:
Introduction / Context:The configuration register is a 16-bit value that directs how a Cisco router boots. The most common setting, 0x2102, tells the device to load the IOS from flash and the startup-config from NVRAM.
Given Data / Assumptions:
Concept / Approach:0x2102 is the factory default. It specifies: use the console speed 9600, load IOS image from flash, and load the startup-config from NVRAM. Alternative values (0x2142) ignore NVRAM (for password recovery); 0x2100 boots ROMMON; 0x2101 boots RXBOOT.
Step-by-Step Solution:
Check register value with 'show version'.Interpret 0x2102: boot system commands are used (if present); otherwise default flash IOS is loaded.Startup-config in NVRAM is loaded after IOS boots.Verification / Alternative check:Change register with 'config-register' command in global config or 'confreg' in ROMMON if needed.
Why Other Options Are Wrong:ROMMON: Value 0x2100. Password recovery: Value 0x2142 ignores NVRAM. TFTP boot: Requires boot system command + TFTP, not default 0x2102.
Common Pitfalls:Misinterpreting 0x2142 vs 0x2102. 2142 is used for recovery, 2102 is default normal operation.
Final Answer:Tells the router to look in NVRAM for the boot sequence
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