Apparatus and method to detect a fault in a communication path by using a detection packet

An apparatus comprising:

• a processor configured to:
• calculate, from information included in a packet received, a first value that is used to select a communication path through which the received packet is to be transmitted to a destination apparatus;
• in response to detecting that the received packet is a detection packet used to detect a fault in a communication path to the destination apparatus,
• obtain a second value by performing a calculation on the first value and a variable value that is changed each time a detection packet is detected to be transmitted, and add an outer header including the second value to the packet, and
• transmit the detection packet to which the outer header including the second value has been added, to the destination apparatus;
• and
• in response to the detecting that the received packet is not a detection packet,
• add an outer header including the first value to the received packet, and
• transmit the received packet to which the outer header including the first value has been added, to the destination apparatus;
• and
• a memory coupled to the processor and configured to store information used for determining whether the received packet is a detection packet.

A method comprising:

• causing an information processing apparatus to:
• calculate, from information included in a packet received, a first value that is used to select a communication path through which the received packet is to be transmitted to a destination apparatus;
• in response to detecting that the received packet is a detection packet used to detect a fault in a communication path to the destination apparatus,
• obtain a second value by performing a calculation on the first value and a variable value that is changed each time a detection packet is detected to be transmitted, and add an outer header including the second value to the packet, and
• transmit the detection packet to which the outer header including the second value has been added, to the destination apparatus;
• in response to the detecting that the received packet is not a detection packet, add an outer header including the first value to the received packet, and
• transmit the received packet to which the outer header including the first value has been added, to the destination apparatus;
• and
• detect a fault by determining whether a reply packet to the detection packet is obtained.