Adesys BV MAC Prefix: Vendor Identified
Summary
- // what this is
- Adesys is registered to MAC prefix
00:21:9Din the IEEE OUI database. When a device's MAC address begins with00:21:9D, that block was registered by Adesys — the OUI identifies the maker of the network hardware, which is not always the brand on the device. - // analyst note
- The prefix is 24 bits long and leaves 24 suffix bits, yielding 16,777,216 possible suffix values, not a device count. The first-byte Group and Local bits are both 0 for this exact prefix; changing either bit produces a different prefix. A match identifies the registry assignment only, not a specific device, product, operating system, current vendor identity, or security state.
About this vendor.
A MAC address beginning 00:21:9D matches an IEEE MA-L assignment registered to Adesys BV; it does not identify a specific device or product. The supplied records do not establish which devices use this prefix.
The prefix is 24 bits long, leaving 24 bits in a 48-bit address. IEEE’s record sets the Group and Local bits to 0. RFC 7042 identifies these as special-significance bits in the initial octet; in the supplied excerpt, it specifies the Local bit as zero for OUIs and longer MAC prefixes, while leaving the Group bit unspecified.
There are 16,777,216 possible suffix values after this prefix. That is a mathematical address-space count, not a device, shipment, or active-address count. Adesys B.V.’s contact page identifies its company name and gives an unambiguous Netherlands location. No product catalog or product-to-prefix mapping is supplied.
- Vendor
- Adesys BV — IEEE MA-L assignment.
- Matching prefix
00:21:9D— 24-bit prefix; match the first 3 octets.- Device identification
- Unknown — no device category is mapped to this exact prefix.
- Country
- The Netherlands — company contact page.
- Company
- Adesys BV [Confirmed] — https://standards-oui.ieee.org/oui/oui.csv
- Registry
- MA-L [Confirmed] — https://standards-oui.ieee.org/oui/oui.csv
- Prefix
00:21:9D[Confirmed] — https://standards-oui.ieee.org/oui/oui.csv- Country
- The Netherlands [Confirmed] — https://www.adesys.nl/en/contact
- Device types
- Unknown [Unknown] — https://standards-oui.ieee.org/oui/oui.csv
- No IEEE date
- Assignment dates are unavailable in these IEEE CSV records. [Confirmed] — https://standards-oui.ieee.org/oui/oui.csv