A method for obtaining segment routing over Internet Protocol version 6 data plane (SRv6) tunnel information of Internet Protocol version 6 segment routing, including sending, by a first network device, a request packet to a second network device, where the request packet is used to request to detect reachability of an SRv6 tunnel and obtain SRv6 tunnel information of the second network device, and the second network device is a network device on the SRv6 tunnel, receiving, by the first network device, a response packet from the second network device, where the response packet includes the SRv6 tunnel information of the second network device, and obtaining, by the first network device, the SRv6 tunnel information of the second network device based on the response packet.