Packet switch test methods include receiving a first packet from a packet switch, receiving a second packet from processing circuitry configured to model expected behavior of the packet switch, comparing the first packet to the second packet, and, based on the comparing, determining whether the packet switch is operating according to the expected behavior. Packet switch modeling methods include identifying functionality of a packet switch to be modeled, creating, in a packet switch model, a plurality of nodes representing physical and/or logical elements of the packet switch, the nodes being configured to process packet data structures and to respectively model different portions of the functionality of the packet switch relative to one another, and, in the packet switch model, connecting the nodes with pathways by which the packet data structures may be forwarded between the nodes.