ong. The Next Header field on the Hop-by-hop option indicates ICMPv6, which is the protocol that actually contains the MLD message. The Router Alert option is required to notify routers that otherwise would not be interested in MLD. The actual beef, SO the speak, of this message is the ICMPv6 packet of type 'Multicast Listener Report Message v2'. With this packet the node informs routers that there are listeners for the Solicited-node multicast address ff02: fff: matching to the link-local address fe80 : ba27 ebff: fef1: 8d0d that the host is going to configure for itself. The detailed contents of the ICMPv6 header are the Deploying IPv6 in 3GPP Networks 'message type' we mentioned, 'code', that in this case is always zero, and the checksum field. It is good to remember that this checksum covers the whole ICMPv6 packet and then the pseudo header, as described in Section 3.10.1, which includes key fields of the previous IPv6 header. The MLDv2 header indicates that this listener report message is of type 'exclude', but because the list of source address to exclude is empty ('Aux data length' field is zero), it effectively means that nothing is excluded and multicast packets from all possible sources destined to the ff02: :fff1:8d0d group should be forwarded to this link. Initiating DAD for IPv6 Link-local Address After the MLD message is sent related to the link-local address that a node has chosen to the use, the node must perform the DAD procedure for the address as described in Section 3.4.7. This ensures that the address is not already in use in the link. As seen on the trace in Figure 3.27, the DAD is performed by sending ICMPv6 Neighbor Solicitation message as multicast to the Solicited-node multicast address ff02: 1:fff1:8d0d of the link- local address that host wants to configure. The packet is not sent to 'all nodes' address of ff02: : 1, as then it would be unnecessarily delivered to all nodes on the link - and not just to those that might be in conflict. Please note that the destination address is the sa