Difficulty: Easy
Correct Answer: service password-encryption
Explanation:
Introduction / Context:
On Cisco IOS devices, plaintext passwords configured under lines (console, vty, aux) or for simple user accounts can be protected from casual viewing in the running-config and startup-config. Understanding which IOS command performs this obfuscation is a core skill for network administrators who audit configurations or harden device security.
Given Data / Assumptions:
Concept / Approach:
The global configuration command service password-encryption turns on a weak, reversible encoding (historically called type 7) that scrambles simple passwords so they do not appear in clear text in configuration files. This is not strong cryptography; it is mainly meant to deter shoulder-surfing and casual disclosure. In contrast, the enable secret command uses a much stronger, hashed representation (for example, type 5 or type 8/9 on newer IOS) but only for the enable password, not for line passwords.
Step-by-Step Solution:
Verification / Alternative check:
If you remove the command and re-enter the same password, the configuration would show it in clear text. Re-enabling the command re-scrambles it. This demonstrates the feature's effect on stored display output.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
service password-encryption
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