This read-write object, typed as IANAifType, specifies the kind of interface -- ATM, LAN, etc. -- associated with this node's primary management IP address recorded in cwtPrimIP. An admin checks this to understand which physical interface type the NMS is using to reach the switch for management. For example, seeing cwtPrimIPIfType indicate an ATM interface tells the admin the primary management path to that node runs over the ATM network rather than a separate LAN connection.