Abstract: Technologies are provided for identifying a source of errors within a computer network that uses cut-through forwarding of network packets. For example, inbound network packets can be received by network devices configured to perform cut-through forwarding. Once the network packets are received, they are processed using cut-through forwarding. If any packet errors are detected, error data associated with the detected errors are stored by the network devices. The error data is transmitted to a monitoring service that uses the error data to create a model of a flow of the errors through the network and to identify a source of the errors. In at least some embodiments, a topology of the network is used by the monitoring service to create the model of the packet error flow.

Abstract: Techniques and solutions are provided for detecting the source of link errors in a cut-through forwarding network fabric. For example, a network link that is the source of the link errors can be automatically located by polling a network device a number of times to identify a network interface that has an increasing error rate and tracing network interface error rates back through one or more upstream network devices to locate the network link that is the source of the link errors.