A string of octets containing one bit per VLAN for
VLANS with VlanIndex values 3072 through 4095. The
first octet corresponds to VLANs with VlanIndex values
3072 through 3079; the second octet to VLANs 3080
through 3087 etc. The most significant bit of each
octet corresponds to the lowest VlanIndex value in that
octet.
For each VLAN that is mapped to this MSTP instance,
the bit corresponding to that VLAN is set to '1'.
Empty (zero) most significant octes are not mandatory.