What does 'no shutdown' do in interface configuration?

• A. It deactivates the interface
• B. It resets IP address
• C. It activates the interface, allowing it to forward traffic
• D. It enables IPv6 ND only

Answer: (C)

The command is used to activate an interface. On many devices, interfaces start administratively down; the opposite of shutting down is no shutdown, which brings the interface up so it can forward frames/packets when the link is active. It does not reset or change the IP address configured on the interface, so the existing IP stays as is. It also isn’t a toggle for IPv6 Neighbor Discovery by itself; ND operates when IPv6 is configured and the interface is up, not simply by issuing this command. So the action described is that the interface becomes active and capable of forwarding traffic.