1. A method comprising: transmitting, by a current root network device, a first unicast message to a network router; determining, by the current root network device, whether the first unicast message is received by one or more other intermediate network devices; if the current root network device determines that the first unicast message is not received by one or more other intermediate network devices, then sending a second unicast message to the network router; and if the current root network device determines that the first unicast message is received by one or more other intermediate network devices, then: identifying, by the current root network device, a particular network device of the one or more other intermediate network devices that received the first unicast message to serve as a new root network device; and sending, by the current root network device, a message to designate the identified particular network device as the new root network device.