An entry in the VLAN By Port Information table.
snVLanByPortVLanIndex = 1 and with
snVLanByPortVLanId = 1 together implies all attributes
applying to the Global switch group i.e. noVLan.
A SNMP SET PDU for a row of the snVLanByPortTable
requires the entired sequence of the MIB Objects in each
snVLanByPortEntry stored in one PDU. Otherwise,
GENERR return-value will be returned.