A string of octets containing one bit per VLAN in the management domain on this trunk port. The first octet corresponds to VLANs with VlanIndex values of 0 through 7; the second octet to VLANs 8 through 15; etc. The most significant bit of each octet corresponds to the lowest value VlanIndex in that octet. If the bit corresponding to a VLAN is set to '1', then the local system is enabled for sending and receiving frames on that VLAN; if the bit is set to '0', then the system is disabled from sending and receiving frames on that VLAN.

To avoid conflicts between overlapping partial updates by multiple managers, i.e., updates which modify only a portion of an instance of this object (e.g., enable/disable a single VLAN on the trunk port), any SNMP Set operation accessing an instance of this object should also write the value of vlanTrunkPortSetSerialNo.