EUI-64 Address Generation

C.

When an EUI-64 address is generated, the MAC address of the interface is used to create a 64-bit interface identifier (IID) with the universal/local bit set to 1, following the format specified in RFC 4291. The universal/local bit indicates whether the IID is globally unique (set to 0) or locally administered (set to 1).

To create the IID, the seventh bit (counting from left to right, starting at 0) of the original MAC address is inverted to obtain a modified MAC address. The characters "FFFE" are then inserted between the vendor portion and the device portion of the modified MAC address to create a 64-bit value. The seventh bit of the modified MAC address is inverted to ensure that the locally administered bit is set to 1, indicating that the address is not globally unique.

Finally, the "Interface ID" is added to the "Prefix" to create a complete IPv6 address. The prefix typically comes from a router advertisement or is manually configured. The resulting IPv6 address has the format "prefix:Interface ID", where the prefix is a 64-bit network prefix and the Interface ID is a 64-bit identifier generated from the MAC address of the interface using the process described above.

Therefore, the correct answer to the question is D: the MAC address of the interface is used as the interface ID without modification, but with the universal/local bit set to 1 to indicate that the address is locally administered.