Who owns MAC prefix A4B439?

A4B439 is registered to Cisco Systems, Inc in the IEEE MA-L registry.

What devices use A4B439?

Any network device with a MAC address starting A4:B4:39 was manufactured by or for Cisco Systems, Inc.

MA-L · OUI prefix

Cisco Systems, Inc

Any MAC address starting A4:B4:39 is registered to Cisco Systems, Inc in US.

OUI prefix	A4B439
Vendor	Cisco Systems, Inc
Registry	MA-L (24-bit, large block)
Country	US
Example MAC	A4:B4:39:00:00:00

What this means

The IEEE assigned the MA-L block A4B439 to Cisco Systems, Inc. Every network interface they manufacture under this block has a MAC address beginning with these digits, followed by a unique per-device identifier. If a device on your network shows a MAC starting A4:B4:39, it is Cisco Systems, Inc hardware.

Other Cisco Systems, Inc prefixes

Cisco Systems, Inc holds 1,248 registered blocks in total.

00000C 000142 000143 000163 000164 000196 000197 0001C7 0001C9 000216 000217 00023D all 1,248 »

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