This attribute specifies the mask which is anded with the attribute
secondMACAddress. The result is then compared with-
a) The destination MAC address in a frame when the attribute direction
has a value of to,
b) The source MAC address in a frame when the attribute direction has a
value of from,
c) Destination/Source address in a frame when the attribute direction has
a value of toFrom, as a part of finding a match in the bridge filter apply
table.