We have begun to expand the NIST quantum key distribution (QKD) system into a quantum network to support secure cryptography. We are starting with a simple three-node network, one Alice switched between Bob1 and Bob2. To support such a quantum network, we have implemented a quantum network manager that not only handles the switch and QKD protocol startup operations but also handles multiplexing and synchronization of secret key streams. We describe the function, structure and interfaces of this quantum network manager and report on initial switching overhead. We also discuss some steps we plan to take to optimize that overhead as well as hide its latency for certain applications.