A system and method are provided for transmitting data via a network. Upon receiving a request for unicast transmission of the data, the system and method respond to the request by i) formatting the data in accordance with a transport protocol to obtain formatted data and ii) providing the formatted data to the network, the formatted data comprising a destination address field. The network is a programmable network comprising one or more forwarding nodes that are remotely controllable. In order to effect a multicasting of the formatted data, the one or more forwarding nodes are controlled to i) replicating the formatted data to obtain replicated formatted data, and ii) setting the destination address field of the replicated formatted data to an address originating from a further request for the unicast transmission of the data. An advantage of the system and method is that multicasting may be provided for ‘off-the-shelf’ unicast receivers.