A data communication method, where a first device receives a request message from at least one second device, where the request message requests the first device to forward group data, and the request message carries a group identifier. The first device returns a response message to the at least one second device, where the response message carries a layer-2 address and an Internet Protocol (IP) address corresponding to the group identifier, and the first device sends the group data using the layer-2 address when receiving the group data sent by a third device to the IP address.