A host is connected to a department network which is part of a university…
2018
A host is connected to a department network which is part of a university network. The university network, in turn, is part of the Internet. The largest network, in which the Ethernet address of the host is unique, is
- A.
the Internet
- B.
the university network
- C.
the department network
- D.
the subnet to which the host belongs
Attempted by 317 students.
Show answer & explanation
Correct answer: A
Correct answer: the Internet
What an Ethernet (MAC) address is: it is a hardware identifier assigned to a network interface and is intended to be globally unique (standard MAC-48/EUI-48 format).
Why the Internet is the largest scope: because MAC addresses are meant to be unique across all networks, the largest network in which that uniqueness holds is the global Internet.
Contrast with IP addresses: IP address uniqueness is often limited to a subnet or a private network and does not imply global uniqueness unless a public IP is assigned.
Note: exceptions exist (for example, locally-administered MAC addresses or deliberate spoofing), but the standard assumption for exam questions is that MAC addresses are globally unique.
A video solution is available for this question — log in and enroll to watch it.