> Out of curiosity: Are there fundamental reasons why ToR switches don't use > the DSA model, or is it more historical?
Yes, there is a fundamental reason. https://www.netdevconf.org/2.1/session.html?lunn_didelot_fainelli DSA always has a host Ethernet interface connected to a port of the switch. A pure switchdev device does not. Often, the switch is a PCIe device. It DMAs frames directly to/from the switch. Basically, DSA just adds another layer, abstracting that Ethernet interface into common code which all DSA devices share. Andrew
