ANSWER=Hosts use IGMP [DA] to announce their membership to a multicast group.
REACTION_CORRECT=The router is the device that listens for the IGMP membership report; it then tells the switch, via CGMP, which port needs to be activated. CGMP must be activated on both the router and the switch.
TEXT_SHOW_ANSWER=The router is the device that listens for the IGMP membership report; it then tells the switch, via CGMP, which port needs to be activated. CGMP must be activated on both the router and the switch.