Method and device for detecting path

The invention discloses a method and a device for detecting a path, and the method and the device are applied to a scene of at least two layers of label forwarding. The method comprises the steps that a first network device generates a first request message for path detection, and the first request message includes a label stack and a TTL, and an initial layer number of the label stack is matched with an initial value of the TTL; and the first request message is sent, the first request is used for indicating a second network device to send a first response message to the first network device in the condition that the TTl-1=0, and the first response message reaches the first network device through an IP path. A condition that the first response message continues to walk a TTL timeout flow is avoided, the time delay of link detection is reduced, and the accuracy of detection is improved. 本申请公开了种检测路径的方法和装置，应用于至少两层标签转发的场景下，所述方法包括：第网络设备生成用于路径检测的第请求报文，所述第请求报文中包括标签栈和TTL，且所述标签栈的初始层数与TTL的初始值相匹配；发送所述第请求报文，所述第请求报文用于指示第二