The index into the Vlan table. A port must be a member of this Vlan prior to assigning this Id as the default. The table has 32 entries (0 - 31). An index value outside this range will reference the local variable. For example if the index is set to -1 and the els10-27VlanEgressVID object is read, the local variable is read, not the table entry. By using an out of range value, the local variables can be read. Only the local variables are written to until els10-27VlanEgressStatus is written.