MAC prefix 00:21:33
Building B, Inc
| Vendor | Building B, Inc |
|---|---|
| Short name | BuildingB |
| Prefix | 00:21:33/24 |
| Block type | MA-L (/24, 16,777,216 addresses) |
| Address range | 00:21:33:00:00:00 – 00:21:33:FF:FF:FF |
| Notations | 00:21:33:00:00:0000-21-33-00-00-000021.3300.0000002133000000 |
Frequently asked questions
Which vendor does MAC address 00:21:33 belong to?
MAC addresses starting with 00:21:33 are assigned to Building B, Inc according to the IEEE registry (prefix length 24 bits).
How many addresses does block 00:21:33 contain?
The block contains 16,777,216 addresses from 00:21:33:00:00:00 to 00:21:33:FF:FF:FF.
Is 00:21:33 a unicast or multicast address?
The least significant bit of the first byte is 0 – it is a unicast address. The U/L bit is 0, so the address is globally unique (universally administered).
How do I find the MAC address of my device?
On Linux use ip link, on Windows getmac /v or ipconfig /all, on macOS ifconfig. Note: phones and recent operating systems often use random, locally administered addresses on Wi-Fi.