Techniques are provided for enabling tag networking. In one example, a network device (e.g., switch, router, etc.) is configured to receive a packet of a traffic flow and to analyze the traffic flow to determine the packet belongs to a particular type of traffic. The network device can then add and/or change a tag in a data field of the packet. The tag, among other things, serves as an identifier for the particular type of traffic flow. The tag is identifiable by a downstream node that is preconfigured to recognize the tag and to carry out logic in response to recognizing the tag. Advantageously, the tag functionality of the present approach provides a generalized way of adding information to packets; the information and the associated functionalities are customizable during a runtime of the network.