The service password-encryption command is entered on a router. What is the effect of this configuration?

This command encrypts all plain-text passwords, such as those configured for console lines, VTY lines, and enable passwords, within the router's configuration files, preventing their easy viewing by unauthorized users accessing the configuration.

The command encrypts passwords once configured in plain text; it does not prevent administrators from *typing* passwords in clear text during configuration.

This command relates to password security on the router's command-line interface and configuration, not to VLAN database protection or switch port security features.

This command encrypts passwords stored locally on the device; it does not encrypt password exchanges or authentication traffic during the establishment of a VPN tunnel, which relies on cryptographic protocols like IPsec.