Systems and methods for performing debugging operations on networks using a controller

Abstract

A controller implemented on computing equipment may control switches in a network. The controller may provide flow tables that implement network policies to the switches to control packet forwarding through the network. The controller may provide debug table entries to the switches for use in a debug table that is separate from the flow table. The debug table entries may match incoming network packets and increment corresponding counters on the switches. The controller may retrieve count information from the counters for performing debugging operations on the network. For example, the controller may identify conflicts between fields of a selected flow table entry, determine whether elephant packet flows are present between switches, determine whether desired load balancing is being performed, determine whether a network path has changed, determine whether packet loss has occurred, and/or determine whether network packets are taking undesired paths based on the retrieved count information.