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Zorluk: Çok zorIPv6 Address Types and EUI-64

An engineer configures a Cisco router interface GigabitEthernet0/0 with a MAC address of 0011.2589.ABCD using the command `ipv6 address 2001:DB8:ACAD:1::/64 eui-64`. Which IPv6 address will be automatically generated on this interface via the EUI-64 process?

  1. 2001:DB8:ACAD:1:211:25FF:FE89:ABCDCevap
  2. B
    2001:DB8:ACAD:1:11:25FF:FE89:ABCD
  3. C
    2001:DB8:ACAD:1:211:25FF:FF89:ABCD
  4. D
    2001:DB8:ACAD:1:11:25FF:FF89:ABCD

Cevap

2001:DB8:ACAD:1:211:25FF:FE89:ABCD
The correct address is constructed by splitting MAC address 0011.2589.ABCD into 0011.25 and 89.ABCD, inserting FFFE into the center to get 0011.25FF.FE89.ABCD, and inverting the 7th bit of the first byte from 0 to 1 (changing 0x00 to 0x02). Appending this interface identifier to prefix 2001:DB8:ACAD:1::/64 yields 2001:DB8:ACAD:1:211:25FF:FE89:ABCD after suppressing leading zeros.

Adım Adım Çözüm

1
Split the 48-bit MAC address into two 24-bit halves.
Left half: 00-11-25, Right half: 89-AB-CD.
The EUI-64 process expands a 48-bit MAC address into a 64-bit Interface Identifier by splitting it at the midpoint.
2
Insert the 16-bit hexadecimal constant FFFE between the two halves.
00-11-25-FF-FE-89-AB-CD.
FFFE is inserted into the center of a 48-bit MAC address to construct a 64-bit IEEE EUI-64 interface identifier.
3
Invert the 7th bit (Universal/Local bit) of the first byte.
First byte 0x00 (binary 0000 0000) becomes 0x02 (binary 0000 0010).
Inverting the 7th bit changes a universally administered MAC address bit into a 1 to indicate global uniqueness within IPv6 interface identifiers.
4
Combine the /64 prefix with the generated 64-bit interface identifier and apply standard IPv6 zero suppression.
2001:DB8:ACAD:1:0211:25FF:FE89:ABCD becomes 2001:DB8:ACAD:1:211:25FF:FE89:ABCD.
Leading zeros in any 16-bit hex field must be omitted per standard IPv6 address formatting rules.

Anahtar Kavram

IPv6 EUI-64 Interface Identifier Generation
Tahmini Süre:1m 30s
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IPv6 Address Types and EUI-64

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