Examkin

Soru

Zorluk: Çok zorIPv6 Address Types and EUI-64

An administrator is auditing a dual-stack network segment where hosts use Stateless Address Autoconfiguration (SLAAC) with EUI-64 to derive their 64-bit interface identifiers. A workstation with the Burned-In MAC address `34-E6-D7-89-0A-1B` sends a Router Solicitation message. What is the correctly formatted IPv6 Link-Local address generated by this interface?

  1. FE80::36E6:D7FF:FE89:0A1BCevap
  2. B
    FE80::34E6:D7FF:FE89:0A1B
  3. C
    FE80::36E6:D7FF:FF89:0A1B
  4. D
    FE80::32E6:D7FF:FE89:0A1B

Cevap

The correct IPv6 Link-Local address is FE80::36E6:D7FF:FE89:0A1B.
To construct an IPv6 EUI-64 interface identifier from a 48-bit MAC address (34-E6-D7-89-0A-1B), the 7th bit (Universal/Local bit) of the first byte must be inverted, and the 16-bit hex value FFFE must be inserted between the third and fourth bytes. The first byte 0x34 is 0011 0100 in binary; flipping the 7th bit produces 0011 0110 (0x36). Inserting FFFE into 36-E6-D7 and 89-0A-1B yields the interface ID 36E6:D7FF:FE89:0A1B. Appending this to the FE80:: link-local prefix forms FE80::36E6:D7FF:FE89:0A1B.

Adım Adım Çözüm

1
Identify the IPv6 Link-Local prefix.
Link-Local addresses begin with FE80::/10 (typically formatted as FE80::/64 for host interfaces).
SLAAC link-local autoconfiguration uses FE80::/64 as the default prefix network segment.
2
Convert the first byte of the MAC address to binary and invert the 7th bit (Universal/Local bit).
The first byte 0x34 in binary is 0011 0100. Inverting the 7th bit (the 2nd least significant bit) changes 0011 0100 to 0011 0110, which is 0x36 in hexadecimal.
IEEE EUI-64 specification requires flipping the U/L bit to indicate a universally administered address modified for EUI-64 usage.
3
Split the modified MAC address into two 24-bit halves and insert FFFE in the middle.
The modified MAC `36-E6-D7-89-0A-1B` becomes `36-E6-D7` and `89-0A-1B`. Inserting `FF-FE` yields `36E6:D7FF:FE89:0A1B` in standard IPv6 hexadecimal notation.
Expanding a 48-bit MAC address into a 64-bit EUI-64 interface identifier requires inserting the 16-bit value FFFE at the center.
4
Combine the link-local prefix with the derived 64-bit EUI-64 interface identifier.
FE80:: + 36E6:D7FF:FE89:0A1B = FE80::36E6:D7FF:FE89:0A1B.
The complete 128-bit link-local address consists of the 64-bit FE80:: prefix and the 64-bit interface ID.

Anahtar Kavram

EUI-64 Interface Identifier Derivation for IPv6 Link-Local Addresses
Tahmini Süre:1m 30s
Bu soruyu puanla

Konular

IPv6 Address Types and EUI-64

Bu konudan daha fazla soru