Patent ID: 8780908

Claim:
A method for tracing a multicast flow in a network including a plurality of network devices, the method comprising: receiving, by an initiating device of the plurality of network devices, a message to trace the multicast flow, the message including an identification of the multicast flow; in response to receiving the message, determining whether a multicast distribution tree of the initiating device includes state information of the multicast flow; in response to determining that the multicast distribution tree includes the state information of the multicast flow: determining an upstream neighbor of the initiating device; transmitting a multicast trace route request to a receiving device of the plurality of network devices, wherein the receiving device is the upstream neighbor of the initiating device; determining whether a response to the multicast trace route request is received from the receiving device; and based on receiving the response, determining whether to transmit by the initiating device a multicast trace route request to an upstream neighbor of the receiving device.