Viewing the configuration register: Which IOS command displays the current configuration register value that controls how the router boots?

Introduction / Context:
The configuration register controls how the router boots: from flash, from ROMMON, or from a TFTP server. It also influences console baud rate and password recovery. Knowing how to view it helps troubleshoot boot issues.

Given Data / Assumptions:

• You are diagnosing boot sequence or password recovery on a Cisco router.
• You need to verify the config-register value (commonly 0x2102).

Concept / Approach:
The 'show version' command displays IOS version, uptime, image file, and the configuration register setting. This is the authoritative way to check the register value from within IOS.

Step-by-Step Solution:

Verification / Alternative check:
From ROMMON mode, 'confreg' can show/change the value, but within IOS it is only visible in 'show version'.

Why Other Options Are Wrong:
show ip route: Displays routing table. show boot version / show flash: Not valid commands for this purpose. 'show flash' lists IOS images in flash, not config-register.

Common Pitfalls:
Confusing 'show running-config' with boot behavior; the config-register is not stored in running-config.

Final Answer:
show version