The MAC address used by the instance of VLAN which
specified in vLanCurrentNumber when it must
be referred to in a unique fashion. It is
recommended that this be the numerically smallest
MAC address of all ports that belong to this
VLAN. However it is only required to be unique.
When concatenated with vStpPriority a unique
BridgeIdentifier is formed which is used in the
Spanning Tree Protocol.