CISCO CCNA Exam – Q137

How is an EUI-64 format interface ID created from a 48-bit MAC address?

A. by appending 0xFF to the MAC address
B. by prefixing the MAC address with 0xFFEE
C. by prefixing the MAC address with 0xFF and appending 0xFF to it
D. by inserting 0xFFFE between the upper three bytes and the lower three bytes of the MAC address
E. by prefixing the MAC address with 0xF and inserting 0xF after each of its first three bytes

Correct Answer: D

Explanation:
The modified EUI-64 format interface identifier is derived from the 48-bit link-layer (MAC) address by inserting the hexadecimal number FFFE between the upper three bytes (OUI field) and the lower three bytes (serial number) of the link layer address.