Patent ID: 8743704

Claim:
A monitoring apparatus that identifies a failure path in a network including a relay device, the monitoring apparatus comprising: a memory; and a processor coupled to the memory and configured to: receive packets that are transmitted in the network, detect a deterioration of quality of a flow between a transmission source subnetwork and a destination subnetwork, the flow corresponding to a received packet from among the received packets, based on information included in the received packets, when the flow is determined to be an equivalent cost multi path (ECMP), separate the flow to a plurality of selection paths by using a routing rule used when the relay device routes a path of the ECMP, perform a quality measurement for each of the selection paths, and identify a failure path among the selection paths based on the quality measurement, wherein the routing rule is based on a result of a modulo calculation using a transmission source address and a destination address of the received packet in which the deterioration of quality has been detected.