Distinguishing between connectivity verification availability and forwarding protocol functionality in a computer network

摘要

In one embodiment, a local network device may determine an inability to establish a connectivity verification protocol (e.g., Bidirectional Forwarding Detection, “BFD”) session to a remote network device, such as from unreturned control messages. In response, the local network device may send at least one connectivity verification protocol echo message to the remote network device destined to be returned to the local network device and forwarded using a forwarding protocol. In response to receiving or not receiving the echo message, the local network device may thus determine whether the forwarding protocol is functioning between the local and remote network devices. In this manner, the local network device may determine whether an inability to establish a connectivity verification protocol session is due to an inability to forward packets between the devices, or due to the connectivity verification protocol not working (or not being configured) on the remote network device.