HP ProCurve 6400cl Series Management And Configuration Manual page 486

MAC Address Management
Determining MAC Addresses
Figure D-3. Example of Port MAC Address Assignments on a 3400cl-24G Switch
D-6
ifPhysAddress.1 - 24: Ports 1 - 24
(A 3400cl-48G switch includes addresses 1 - 48 for
the fixed ports.)
ifPhysAddress.25 - 26: Ports 25 - 26
(Addresses 25 - 26 appear only if a 10-gigabit
expansion module is installed in the switch. On a
3400cl-48G switch, these ports are numbered 49
and 50.)
ifPhysAddress.102 Base MAC Address
(MAC Address for default
VLAN; VID = 1)