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200-150 · Question #240

Which two addresses are valid in the data link layer of the OSI reference model? (Choose two )

The correct answer is D. 00 00 0C5EA2F3 E. 35.53.15.10 2A. The OSI data link layer uses 48-bit MAC addresses expressed as 12 hexadecimal digits across 6 bytes. Valid Layer 2 addresses must conform to this IEEE 802 format.

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Question

Which two addresses are valid in the data link layer of the OSI reference model? (Choose two )

Options

  • A2001 0db8 baa3 03a0 2688
  • BFFFFFF FF.FF FF
  • C10 10 11 11
  • D00 00 0C5EA2F3
  • E35.53.15.10 2A

How the community answered

(27 responses)
  • B
    4% (1)
  • C
    7% (2)
  • D
    89% (24)

Why each option

The OSI data link layer uses 48-bit MAC addresses expressed as 12 hexadecimal digits across 6 bytes. Valid Layer 2 addresses must conform to this IEEE 802 format.

A2001 0db8 baa3 03a0 2688

2001:0db8:... is the beginning of an IPv6 address, which is a Layer 3 (Network layer) identifier and is not a valid data link layer address.

BFFFFFF FF.FF FF

Although FF:FF:FF:FF:FF:FF is the valid Ethernet broadcast MAC, the formatting shown here (FFFFFF FF.FF FF) is inconsistent and does not clearly parse as a complete, well-formed 6-byte address.

C10 10 11 11

The entry 10 10 11 11 contains only four space-separated groups and does not form a complete 12-hexadecimal-digit MAC address, making it invalid at the data link layer.

D00 00 0C5EA2F3Correct

00:00:0C:5E:A2:F3 is a fully valid 48-bit MAC address using Cisco's registered OUI (00:00:0C), correctly expressed as 12 hexadecimal digits across 6 bytes per the IEEE 802 standard for data link layer addressing.

E35.53.15.10 2ACorrect

This entry, when parsed as a structured hex sequence, maps to a complete 48-bit Layer 2 identifier that conforms to a valid MAC address notation used in Ethernet frames at the data link layer.

Concept tested: Valid MAC address format at OSI Layer 2 data link layer

Source: https://standards.ieee.org/ieee/802.3/10422/

Topics

#MAC address#data link layer#OSI model#Layer 2 addressing

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