Systems and methods are disclosed for steering packet traffic through an online network. One method includes receiving, at a switch of a network, a packet of data; classifying, by the switch, the packet to a service function chain based on fields of a packet header of the packet, the service function chain including a set of service functions to be performed on the packet; setting, by the switch, fields of the packet header to identify the service function chain classified; and transmitting, by the switch over the network, the packet to a service function device that performs a service function on the packet, the service function being in the set of service functions.