Path detection

A forwarding device, comprising:

• a processor, and
• a machine-readable storage medium storing machine-executable instructions that, when executed by the processor, cause the processor to:
• receive a first detection packet sent from a previous hop forwarding device on a path of a designated service flow and used for detecting the path of the designated service flow, wherein forwarding information in a header of the first detection packet is the same as forwarding information in a header of the designated service flow, and a device address of at least one forwarding device on the path of the designated service flow is carried in a payload of the first detection packet;
• obtain a second detection packet by adding a device address of the present forwarding device to the payload of the first detection packet;
• forward the second detection packet to a next hop forwarding device on the path of the designated service flow based on the forwarding information in a header of the second detection packet;
• and
• send to a SDN controller a forwarding error message in which the device address of the at least one forwarding device in the payload of the first detection packet is carried, such that the SDN controller determines the path of the designated service flow based on the device address carried in the forwarding error message.

A machine-readable storage medium storing machine-executable instructions that, when invoked and executed by a processor of a forwarding device, cause the processor to:

• receive a first detection packet sent from a previous hop forwarding device on a path of a designated service flow and used for detecting the path of the designated service flow, wherein forwarding information in a header of the first detection packet is the same as forwarding information in a header of the designated service flow, and a device address of at least one forwarding device on the path of the designated service flow is carried in a payload of the first detection packet;
• obtain a second detection packet by adding a device address of the present forwarding device to the payload of the first detection packet;
• forward the second detection packet to a next hop forwarding device on the path of the designated service flow based on the forwarding information in a header of the second detection packet;
• and
• send to a SDN controller a forwarding error message in which the device address of the at least one forwarding device in the payload of the first detection packet is carried, such that the SDN controller determines the path of the designated service flow based on the device address carried in the forwarding error message.