Patent ID: 9553795
Date: 2017-01-24
CPC Classifications: H04L

Claim:
1. A port switching method executed by a processor included in an analysis device coupled to a first port and a second port, each of the first port and the second port being included in at least one of a plurality of switches, the plurality of switches being capable of copying a packet to generate a copy packet, the port switching method comprising: receiving a first copy packet from the first port; storing a sequence number of a second copy packet in a memory when the second copy packet is received; extracting a sequence number of the first copy packet when the first copy packet is received determining whether the first copy packet succeeded the second copy packet based on the sequence number of the first copy packet, and based on the sequence number of the second copy packet received before the receiving; specifying a target port outputted the first copy packet to the first port, the target port being coupled to the first port and the second port and included in a target switch among the plurality of switches, when it is determined that the first copy packet did not succeed the second copy packet; and causing the target switch to transmit, from the target port, a third copy packet generated at the target switch to the analysis device through the second port without passing the first port, wherein the determining includes: determining that the first copy packet succeeded the second copy packet, when the sequence number of the first copy packet succeeded the sequence number of the second copy packet stored in the memory, and determining that the first copy packet did not succeed the second copy packet, when the sequence number of the first copy packet did not succeed the sequence number of the second copy packet stored in the memory.