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Difficulty: MediumIPv6 Address Types and EUI-64

An administrator is verifying IPv6 stateless address autoconfiguration (SLAAC) on an Ethernet interface with a burned-in MAC address of 0011.2233.4455. Which TWO statements accurately describe the standard EUI-64 interface identifier generation process for this interface? (Select two.)

  1. The hexadecimal value fffe is inserted into the middle of the 48-bit MAC address between the third and fourth bytes.Answer
  2. The resulting 64-bit interface identifier derived from the MAC address is 0211:22ff:fe33:4455.Answer
  3. C
    The hexadecimal value ffff is inserted into the middle of the 48-bit MAC address to expand it to 64 bits.
  4. D
    The 7th bit of the first byte of the MAC address remains unchanged to preserve original burned-in MAC formatting, resulting in 0011:22ff:fe33:4455.

Answer

The correct statements are that the hexadecimal value fffe is inserted into the middle of the MAC address between the third and fourth bytes, and the resulting derived 64-bit interface identifier is 0211:22ff:fe33:4455.
Generating an IPv6 EUI-64 interface identifier from a 48-bit MAC address requires two key steps: inserting the 16-bit hex value fffe into the middle of the MAC address between the 3rd and 4th bytes, and inverting the 7th bit (Universal/Local bit) of the first byte. For MAC 0011.2233.4455, the first byte 0x00 (0000 0000) becomes 0x02 (0000 0010), and inserting fffe produces 0211:22ff:fe33:4455.

Step-by-Step Solution

1
Split the MAC address into two 24-bit halves and insert fffe into the midpoint.
Splitting 0011.2233.4455 into 0011.22 and 33.4455 and inserting fffe yields 0011:22ff:fe33:4455.
IEEE EUI-64 expansion converts a 48-bit MAC address into a 64-bit interface identifier by inserting the 16-bit pattern fffe in the middle.
2
Invert the 7th bit (Universal/Local bit) of the first byte.
First byte 0x00 binary is 0000 0000. Inverting the 7th bit gives 0000 0010, which is 0x02.
IPv6 modifies the 7th bit of the OUI to represent universal scope when derived via EUI-64.
3
Combine the inverted first byte with the rest of the expanded interface identifier.
The final 64-bit interface identifier is 0211:22ff:fe33:4455.
Replacing 00 with 02 in the initial 16-bit block forms the complete, valid EUI-64 host portion.

Key Concept

EUI-64 Interface Identifier Derivation
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Topics

IPv6 Address Types and EUI-64

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