Effect of service password-encryption command

A.

The "service password-encryption" command is a Cisco IOS configuration command used to encrypt plain-text passwords stored in the router's running configuration. When this command is configured, any plain-text passwords that are stored in the configuration will be replaced with encrypted versions. This is a basic security measure that is used to help protect against unauthorized access to sensitive information.

Option A is the correct answer. The "service password-encryption" command restricts unauthorized users from viewing clear-text passwords in the running configuration. This means that if someone gains access to the router's configuration file, they will not be able to view any plain-text passwords. Instead, the passwords will appear as encrypted text, making it more difficult for an attacker to use them for malicious purposes.

Option B is not correct. The "service password-encryption" command does not prevent network administrators from configuring clear-text passwords. It only encrypts existing plain-text passwords stored in the running configuration. Network administrators can still configure new passwords in clear-text format.

Option C is also not correct. The "service password-encryption" command does not protect the VLAN database from unauthorized PC connections on the switch. It only encrypts plain-text passwords stored in the router's running configuration.

Option D is also not correct. The "service password-encryption" command does not encrypt the password exchange when a VPN tunnel is established. It only encrypts plain-text passwords stored in the router's running configuration.

In summary, the "service password-encryption" command is a basic security measure that helps protect against unauthorized access to sensitive information by encrypting plain-text passwords stored in the router's running configuration.