  The distribution of entangled states across the nodes of a future quantum
internet will unlock fundamentally new technologies. Here we report on the
experimental realization of a three-node entanglement-based quantum network. We
combine remote quantum nodes based on diamond communication qubits into a
scalable phase-stabilized architecture, supplemented with a robust memory qubit
and local quantum logic. In addition, we achieve real-time communication and
feed-forward gate operations across the network. We capitalize on the novel
capabilities of this network to realize two canonical protocols without
post-selection: the distribution of genuine multipartite entangled states
across the three nodes and entanglement swapping through an intermediary node.
Our work establishes a key platform for exploring, testing and developing
multi-node quantum network protocols and a quantum network control stack.
