Description: Contains the list of the ports grouped together in this Virtual Broadcast Domain. The representation is a bit map. Each octet within the value of this object specifies a set of eight ports, with the first octet specifying ports 1 through 8, the second octet specifying ports 9 through 16, etc. Within each octet, the most significant bit represents the lowest numbered port, and the least significant bit represents the highest numbered port. Thus, each port of the switch is represented by a single bit within the value of this object. If that bit has a value of <1> then that port is included in the set of ports; the port is not included if its bit has a value of <0>. Note that the setting of the bit corresponding to the port from which a frame is received is irrelevant. The default value of this object is a string of ones of appropriate length, except for the source port bit.