In some examples, a method includes identifying, by a network switching device, a network packet received via a particular port as a Message Queuing Telemetry Transport (MQTT) packet, wherein the MQTT packet is transmitted between a broker device and a subscriber device; performing, by the network switching device, a deep packet inspection (DPI) to identify a network address corresponding to the broker device; applying, by the network switching device, a network policy defined in a policy engine that is specific to at least one of the broker device and the subscriber device, wherein the at least one of the broker device and the subscriber device is not statically configured in the policy engine; and performing, by the network switching device, a specific action based on the applied network policy.