Issues Related to Transitioning to IPv6 IPv4-compatible addresses are assigned exclusively to nodes that support automatic tunneling. A node should be configured with an IPv4-compatible address only if it is prepared to accept IPv6 packets destined to that address encapsulated in IPv4 packets destined to the embedded IPv4 address. An IPv4-compatible address is globally unique as long as the IPv4 address is not from the private IPv4 address space. An implementation should behave as if its IPv4-compatible address(es) are assigned to the node's automatic tunneling interface, even if the implementation does not implement automatic tunneling using a concept of interfaces. Thus, the IPv4-compatible address should not be viewed as being attached to, for example, an Ethernet interface, that is, implications should not use the Neighbor Discovery mechanisms such as NUD (RFC 2461) at the Ethernet. Any such interactions should be done using the encapsulated packets i.e., over the automatic tunneling (conceptual) interface. 8.5.2 IPv4-Compatible Address Configuration An IPv6/IPv4 node with an IPv4-compatible address uses that address as one of its IPv6 addresses, while the IPv4 address embedded in the low-order 32-bits serves as the IPv4 address for one of its interfaces. An IPv6/IPv4 node may acquire its IPv4-compatible IPv6 addresses via IPv4 address configuration proto- cols. It may use any IPv4 address configuration mechanism to acquire its IPv4 address, then "map" that address into an IPv4-compatible IPv6 address by pre-pending it with the 96-bit prefix 0:0:0:0:0:0. This mode of con- figuration allows IPv6/IPv4 nodes to "leverage" the installed base of IPv4 address configuration servers. The specific algorithm for acquiring an IPv4-compatible address using IPv4-based address configuration protocols is as follows: