1. A network device comprising: a plurality of packet forwarding elements, each including a hardware component for receiving and forwarding data packets from and to other network devices via a plurality of input ports when connected to a network, each hardware component configured to: determine whether a received data packet, based on data in the received data packet, is one of a predetermined class of data packets that must be forwarded in an expedited fashion to each packet forwarding element of the plurality of packet forwarding elements of the network device and, if so: generate expedited processing instructions corresponding to the received data packet based on data in the received data packet, the expedited processing instructions comprising instructions which enable the hardware component to forward the received data packet directly to the hardware component of each packet forwarding element of the plurality of packet forwarding elements with involvement of not more than one central processing unit; and forward the received data packet together with the corresponding expedited processing instructions as a modified data packet directly to the hardware component of each packet forwarding element of the plurality of packet forwarding elements via a switch fabric for processing of the received data packet by each packet forwarding element using the expedited processing instructions.