How is an IPv6 solicited-node multicast address calculated from a unicast address?

An IPv6 solicited-node multicast address is derived from a given unicast address using a specific process. The correct method involves taking the prefix "ff02::1:ff" and appending the last six hex digits of the unicast address. This results in a solicited-node multicast address that is used for Neighbor Discovery Protocol and other similar activities.

For example, if the unicast address is 2001:0db8:85a3:0000:0000:8a2e:0370:7334, the last six hex digits are "0370:7334." When you concatenate those with the prefix "ff02::1:ff," you get "ff02::1:ff:70:7334," which is the solicited-node multicast address for that particular unicast address.

This method allows devices on the same local link to communicate efficiently when they need to determine the link-layer address of a neighbor node without flooding the entire network with multicast traffic. The use of the last six hex digits ensures that each solicited-node multicast address is unique for different unicast addresses on the same link.

Understanding this calculation is essential for comprehending how IPv6 multicast addresses work during the operation of network protocols that