Examkin

Question

Difficulty: EasyIPv6 Addressing and Prefixes

A network administrator is configuring SLAAC on a router interface for a host with the MAC address `0012.3456.789A`. What is the 64-bit interface identifier generated using the EUI-64 process?

  1. 0212:34ff:fe56:789aAnswer
  2. B
    0012:34ff:fe56:789a
  3. C
    0212:34fe:ff56:789a
  4. D
    0212:3456:789a:fffe

Answer

The correct interface identifier is 0212:34ff:fe56:789a.
The EUI-64 calculation process requires splitting the 48-bit MAC address (00:12:34:56:78:9A) into two equal halves, inserting FFFE in the middle (0012:34FF:FE56:789A), and flipping the 7th bit of the first byte (00000000 becomes 00000010, or 02 in hex). This yields 0212:34ff:fe56:789a.

Step-by-Step Solution

1
Split the 48-bit MAC address into two 24-bit halves.
Left half: 00:12:34, Right half: 56:78:9A
EUI-64 requires inserting a 16-bit payload between the Organizationally Unique Identifier (OUI) and the NIC-specific portion.
2
Insert FFFE between the two halves.
00:12:34:FF:FE:56:78:9A
This expands the 48-bit MAC address into a 64-bit value.
3
Invert the 7th bit (Universal/Local bit) of the first byte.
First byte 00 (00000000 in binary) becomes 02 (00000010 in binary). Resulting string: 02:12:34:FF:FE:56:78:9A
Inverting the 7th bit indicates that the address is globally unique.
4
Format the resulting 64-bit value into four 16-bit IPv6 hextets.
0212:34ff:fe56:789a
Standard IPv6 address notation groups 16-bit blocks separated by colons.

Key Concept

EUI-64 Interface Identifier Generation
Estimated Time:45s
Rate this question

Topics

IPv6 Addressing and Prefixes

More questions from this topic