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Zac67 ♦
Zac67 ♦
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MAC address: DE:AD:BE:EF:00:00

That is a locally administered MAC address (LAA) as indicated by the second-least significant bit in the first octet (0xE = 1110b). As such, it is the responsibility of the user/administrator to make sure it's unique in their network.

AFAIK there's no regulation prohibiting such a practice (there should be) but it may be considered unprofessional. Devices being shipped with identical MAC addresses, without a mechanism to ensure uniqueness (in a network) before use, can be considered broken - but only if these addresses are actually used on an external interface.

TCP/IP traffic is still routed to the actual endpoint via MAC addressing on the network layer, hence the need for unique MAC addresses.

IP uses IP addresses for routing. MAC addresses are used over an unlying, MAC-based data link layer network to enable proper delivery of the encapsulating network frame, but many data link layer networks have other mechanisms for local delivery and don't use MAC addresses.

What you're seeing is likely just a virtual (or abstracted) adapter's dummy address that is presented towards the OS but not actually used anywhere. Mobile devices don't use MAC addresses towards their cell service, they use IMEI addresses. So, MAC duplication problems don't apply here.

(MAC'Universal' MAC addresses (UAA) aren't really globally unique any more, but it's the vendor's responsibility to ensure that it's impossible or at least extremely unlikely that two devices with the same address see each other in any network.)

MAC address: DE:AD:BE:EF:00:00

That is a locally administered MAC address as indicated by the second-least significant bit in the first octet (0xE = 1110b). As such, it is the responsibility of the user/administrator to make sure it's unique in their network.

AFAIK there's no regulation prohibiting such a practice (there should be) but it may be considered unprofessional. Devices being shipped with identical MAC addresses, without a mechanism to ensure uniqueness (in a network) before use, can be considered broken - but only if these addresses are actually used on an external interface.

What you're seeing is likely just a virtual adapter's dummy address that is presented towards the OS but not actually used anywhere. Mobile devices don't use MAC addresses towards their cell service, they use IMEI addresses. So, MAC duplication problems don't apply here.

(MAC addresses aren't really globally unique any more, but it's the vendor's responsibility to ensure that it's impossible or at least extremely unlikely that two devices with the same address see each other in any network.)

MAC address: DE:AD:BE:EF:00:00

That is a locally administered MAC address (LAA) as indicated by the second-least significant bit in the first octet (0xE = 1110b). As such, it is the responsibility of the user/administrator to make sure it's unique in their network.

AFAIK there's no regulation prohibiting such a practice (there should be) but it may be considered unprofessional. Devices being shipped with identical MAC addresses, without a mechanism to ensure uniqueness (in a network) before use, can be considered broken - but only if these addresses are actually used on an external interface.

TCP/IP traffic is still routed to the actual endpoint via MAC addressing on the network layer, hence the need for unique MAC addresses.

IP uses IP addresses for routing. MAC addresses are used over an unlying, MAC-based data link layer network to enable proper delivery of the encapsulating network frame, but many data link layer networks have other mechanisms for local delivery and don't use MAC addresses.

What you're seeing is likely just a virtual (or abstracted) adapter's dummy address that is presented towards the OS but not actually used anywhere. Mobile devices don't use MAC addresses towards their cell service, they use IMEI addresses. So, MAC duplication problems don't apply here.

('Universal' MAC addresses (UAA) aren't really globally unique any more, but it's the vendor's responsibility to ensure that it's impossible or at least extremely unlikely that two devices with the same address see each other in any network.)

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Zac67 ♦
Zac67 ♦
  • 88.1k
  • 4
  • 73
  • 137

MAC address: DE:AD:BE:EF:00:00

That is a locally administered MAC address as indicated by the second-least significant bit in the first octet (0xE = 1110b). As such, it is the responsibility of the user/administrator to make sure it's unique in their network.

AFAIK there's no regulation prohibiting such a practice (there should be) but it may be considered unprofessional. Devices being shipped with identical MAC addresses, without a mechanism to ensure uniqueness (in a network) before use, can be considered broken - but only if these addresses are actually used on an external interface.

What you're seeing is likely just a virtual adapter's dummy address that is presented towards the OS but not actually used anywhere. Mobile devices don't use MAC addresses towards their cell service, they use IMEI addresses. So, MAC duplication problems don't apply here.

(MAC addresses aren't really globally unique any more, but it's the vendor's responsibility to ensure that it's impossible or at least extremely unlikely that two devices with the same address see each other in any network.)