**To view the information about the transit gateway multicast domain associations** This example returns the associations for the specified transit gateway multicast domain. :: aws ec2 register-transit-gateway-multicast-group-members \ --transit-gateway-multicast-domain-id tgw-mcast-domain-0c4905cef79d6e597 \ --group-ip-address 224.0.1.0 \ --network-interface-ids eni-0e246d32695012e81 Output:: { "RegisteredMulticastGroupMembers": { "TransitGatewayMulticastDomainId": "tgw-mcast-domain-0c4905cef79d6e597", "RegisteredNetworkInterfaceIds": [ "eni-0e246d32695012e81" ], "GroupIpAddress": "224.0.1.0" } } For more information, see `Register Members with a Multicast Group <https://docs.aws.amazon.com/vpc/latest/tgw/working-with-multicast.html#add-members-multicast-group>`__ in the *AWS Transit Gateways User Guide*.