MAC

media access control - mac address - usually displayed in hex - 6 groups of 2 hex digits - 1st 3 octets is generally OUI (Organiationally Unique Identifier) - burnt into NIC

- only LAN-unique, not globally unique
    - vendors sometimes sell devices w same MAC addresses in dif parts of the world where they are unlikely to show up
    - duplicate MACs on a LAN would cause a lot of collisions
    - same MACs separated by router okay bc in different LAN
- can be subject to MAC [[spoofing]]
    - fake a MAC address