Patent ID: 9143447
Filing Date: 2015-09-22
Classification: H04L,Y02D

Abstract:
1. A closed loop formation preventing system comprising: a switch configured to receive a packet and transfer the packet based on a flow entry registered on a flow table; and a controller configured to register the flow entry on the flow table in response to an inquiry from said switch, wherein said switch comprises: means for confirming whether or not the received packet is a test packet; means for confirming whether or not there is the flow entry matching the received packet in existing flow entries of the flow table, when the received packet is not the test packet; means for inquiring to said controller when there is no flow entry matching to the received packet; generating means for generating the test packet based on the flow entry temporarily registered from said controller; means for retaining the received packet, transferring the test packet based on the temporarily registered flow entry and starting a test for detecting formation of a closed loop; and means for discarding the temporarily registered flow entry when detecting the formation of the closed loop as a result of the test.