Who owns MAC prefix B838EF?

B838EF is registered to ADVA Optical Networking Ltd. in the IEEE MA-L registry.

What devices use B838EF?

Any network device with a MAC address starting B8:38:EF was manufactured by or for ADVA Optical Networking Ltd..

MA-L · OUI prefix

ADVA Optical Networking Ltd.

Any MAC address starting B8:38:EF is registered to ADVA Optical Networking Ltd..

OUI prefix	B838EF
Vendor	ADVA Optical Networking Ltd.
Registry	MA-L (24-bit, large block)
Example MAC	B8:38:EF:00:00:00

What this means

The IEEE assigned the MA-L block B838EF to ADVA Optical Networking Ltd.. 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 B8:38:EF, it is ADVA Optical Networking Ltd. hardware.

Other ADVA Optical Networking Ltd. prefixes

ADVA Optical Networking Ltd. holds 7 registered blocks in total.

000B90 0080EA 00D08B 18BC57 289AF7 84C807

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