IT Devel

IPv6 - Solicited-Node Multicast Address

Global 이든 Link-local 이든 Unicast 주소를 인터페이스에 하나씩 할당 할 때 마다, 아래와 같은 "Solicited-Node Multicast Address"가 하나씩 있어야 한다. (또는 처리할 수 있어야 한다.)
아래 주소로 패킷이 들어왔는데, 처리하지 않으면 이상하겠지.
스펙상 의도하여 생성하지 않았지만 각 unicast 주소에 저절로 맵핑되어야 하는 것이므로

추가) 당연히 all nodes multicast 주소인 "FF02::1"과 로컬주소 "::1" 도 처리해 주어야 겠지 =)

Mapping Unicast IPv6 Addresses to Solicited Node IPv6 Addresses

For example, for the node with the link-local IPv6 address of FE80::2AA:FF:FE28:9C5A, the corresponding solicited-node address is FF02::1:FF28:9C5A. This node is listening for multicast traffic at the solicited-node address of FF02::1:FF28:9C5A and, for interfaces that correspond to a physical network adapter, has registered the corresponding multicast address with the network adapter. To resolve the address of FE80::2AA:FF:FE28:9C5A to its link-layer address, a neighboring node sends a Neighbor Solicitation to the solicited-node address of FF02::1:FF28:9C5A.

The result of using the solicited-node multicast address is that address resolutions, a common occurrence on a link, are not required to use a mechanism that disturbs all network nodes. By using the solicited-node address, address resolution disturbs very few nodes. In practice, due to the relationship between the Ethernet MAC address, the IPv6 interface ID, and the solicited-node address, the solicited-node address acts as a pseudo-unicast address for very efficient address resolution.