Clearing saved configuration On a Cisco router, which command deletes the contents of NVRAM by erasing the saved startup configuration so the device boots with a default configuration on the next reload?

Introduction / Context:
NVRAM stores the startup configuration that a Cisco router loads during boot. When you need to factory-reset the device's saved configuration (for lab work, decommissioning, or troubleshooting), you erase the startup-config stored in NVRAM. Knowing the correct command and its common abbreviations prevents accidental data loss or confusion about what configuration file you are modifying.

Given Data / Assumptions:

• The goal is to remove the saved configuration in NVRAM (startup-config), not the running-config in RAM.
• We are using classic IOS CLI where command abbreviations are accepted.
• A reload after erasing is typically required to take effect cleanly.

Concept / Approach:

The canonical command is often entered as erase startup-config. IOS supports unambiguous abbreviations, so erase start is commonly used and accomplishes the same task. Alternative historical forms include write erase on many platforms, which also erases the startup-config. After erasing, reloading the router causes it to start with the default, unconfigured state.

Step-by-Step Solution:

Verification / Alternative check:

Running show startup-config before and after confirms that NVRAM has been cleared. Upon reload, the initial setup dialog appears, confirming the absence of a saved configuration.

Why Other Options Are Wrong:

• delete NVRAM / erase NVRAM: not standard, platform-independent IOS commands.
• delete startup-config: on some platforms it may work, but the standard lab-proven method is erase startup-config; the question expects that form or its abbreviation.
• write erase: is valid on many systems but is not among the choices marked correct here; the provided correct equivalent is erase start.

Common Pitfalls:

• Confusing running-config with startup-config; erasing NVRAM does not immediately change the running configuration until reload.
• Forgetting to save a backup before erasing if the config is needed later.

Final Answer:

erase start