Final answer:
The role of a tunneling interface is to transmit data between nodes and subnets securely by encapsulating network protocols within packets carried by another network, typically done for creating VPNs.
Step-by-step explanation:
In the context of the provided terms, the role of a tunneling interface is primarily to transmit data between nodes and subnets. A tunneling interface enables the creation of virtual private networks (VPNs) by encapsulating a network protocol within packets carried by the second network. This encapsulation allows data to be transmitted securely over a public network as if it were a private connection. It effectively bridges the data across various network boundaries or intermediary routers without altering the routing infrastructure already in place. As such, it is not directly involved in the connecting configuration or headers, nor does it handle routing headers within a network. Instead, it establishes a point-to-point connection that can encapsulate different types of traffic, such as IP, allowing for secure communication between remote networks or nodes through potentially insecure network spaces.