Network addresses are dynamically allocated to devices based on demand. A first network address allocation is initially assigned to a subdivision of a network including multiple computing devices. A router for the subdivision is configured to implement the first network address allocation. Data indicating a reconfiguration of the computing devices is obtained. A second network address allocation is subsequently assigned to the subdivision of the network based at least in part on the reconfiguration of the computing devices. The router for the subdivision is reconfigured to implement the second network address allocation.