Reference : RFC 2863: The Interfaces Group MIB - ifPhysAddressStatus : DEPRECATEDThe interface's address at its protocol sub-layer. For
example, for an 802.x interface, this object normally
contains a Media Access Control (MAC) address. The
interface's media-specific modules must define the bit
and byte ordering and the format of the value of this
object. For interfaces that do not have such an address
(e.g., a serial line), this node is not present.