Ethernet address types

Last 2 bits of 1st byte gives type:
- 00:01:02:03:04:050000 0000: unicast (single host)
- 01:01:02:03:04:050000 0001: multicast (group of hosts)
- ff:ff:ff:ff:ff:ff: broadcast (all hosts)
  - Special case of multicast

Last 2 bits of 1st byte gives type: