A string of octets containing one bit per VLAN for
VLANs 2048 to 4095 that are active in this FabricPath
topology entry.
If the bit corresponding to a VLAN is set to '1', then
the VLAN is active in this FabricPath topology. If the
bit is set to '0', then the VLAN is not active in this
FabricPath topology.