A method and system for monitoring data packet traffic in a multicast network comprising determining a first packet count received at a receiver router, representing a quantity of data packets associated with a multicast group and source at a first time, determining a second packet count received at that receiver router representing a quantity of data packets associated with that multicast group and source, at a second time subsequent to the first time, comparing the second packet count to the first packet count, and indicating an alarm in response to the second packet count being less than a predetermined value greater than the first packet count. A status for multiple routers can be obtained, comprising a difference between the quantity of the first and second packet counts; and indicating a warning in response to at least one of the plurality of router status being less than the predetermined value.