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GCIA · Question #11

You work as a network administrator for BlueWell Inc. You have to convert your 48-bit host address (MAC address) to an IPv6 54-bit address. Using the IEEE-EUI-64 conversion process, how do you convert

The correct answer is D. Add FF. FE between the third and fourth bytes. The IEEE EUI-64 process converts a 48-bit MAC address to a 64-bit interface identifier by inserting the hex value FF:FE between the third and fourth bytes of the MAC address.

Advanced Incident Response & Digital Forensics Fundamentals

Question

You work as a network administrator for BlueWell Inc. You have to convert your 48-bit host address (MAC address) to an IPv6 54-bit address. Using the IEEE-EUI-64 conversion process, how do you convert the 48-bit host address (MAC address) to an IPv6 54-bit address?

Options

  • AAdd EF. FE between the third and fourth bytes.
  • BAdd FE. EE between the third and fourth bytes.
  • CAdd FF. EE between the third and fourth bytes.
  • DAdd FF. FE between the third and fourth bytes

How the community answered

(52 responses)
  • A
    4% (2)
  • B
    6% (3)
  • C
    10% (5)
  • D
    81% (42)

Why each option

The IEEE EUI-64 process converts a 48-bit MAC address to a 64-bit interface identifier by inserting the hex value FF:FE between the third and fourth bytes of the MAC address.

AAdd EF. FE between the third and fourth bytes.

EF:FE is not the value specified by IEEE for EUI-64 expansion - only FF:FE is the standardized insertion value.

BAdd FE. EE between the third and fourth bytes.

FE:EE is an incorrect value and does not correspond to any part of the IEEE EUI-64 specification.

CAdd FF. EE between the third and fourth bytes.

FF:EE is incorrect - the second byte of the inserted value must be FE, not EE, per the IEEE EUI-64 standard.

DAdd FF. FE between the third and fourth bytesCorrect

In the EUI-64 process defined by IEEE and used in IPv6 stateless address autoconfiguration (SLAAC), the 48-bit MAC address is split after its first three octets (the OUI), and the two-byte sequence FF:FE is inserted at that midpoint to produce a 64-bit identifier. Additionally, the universal/local (U/L) bit - the seventh bit of the first byte - is flipped to indicate global uniqueness. FF:FE is the specific reserved value mandated by the IEEE specification for this purpose.

Concept tested: IEEE EUI-64 MAC to IPv6 interface identifier conversion

Source: https://www.rfc-editor.org/rfc/rfc4291#appendix-A

Topics

#EUI-64#IPv6 addressing#MAC address conversion#network addressing

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