US Patent 7978602 Dynamic construction of label switching protocol interfaces

Techniques are described for dynamically constructing a label switching protocol interface in a network device. For example, the techniques allow dynamic construction of a Multi-Protocol Label Switching (MPLS) interface. According to some embodiments, upon receiving a network communication from a subscriber, a network device determines whether the subscriber requires support for the label switching protocol. If the subscriber requires such support, the network device creates an interface stack for the subscriber that includes an interface for the label switching protocol. In this way, the network device may route packets from the subscriber across a network of computing devices that use the label switching protocol, and forward packets from such a network to the subscriber. The subscriber and the network device need not communicate according to the label switching protocol and, in example embodiments, instead communicate according to a layer 2 communication protocol.