A method comprising: exchanging, by a central routing device and with an ingress routing device that is communicatively coupled to at least one source device (2, 4), a plurality of targeted hello messages to establish a targeted neighbor connection between the central routing device and the ingress routing device, wherein the targeted neighbor connection comprises a reliable transport connection, and wherein exchanging the plurality of targeted hello messages comprises: receiving, by the central routing device and from the ingress routing device, a first targeted hello message comprising a first unicast message that is addressed to the central routing device; and sending, by the central routing device and to the ingress routing device, a second targeted hello message to acknowledge receipt of the first targeted hello message, wherein the second targeted hello message comprises a second unicast message that is addressed to the ingress routing device; receiving, by the central routing device and from the ingress routing device using the targeted neighbor connection, a source-active register message that specifies a source address and an identifier that are collectively associated with a multicast stream provided by the at least one source device (2, 4), wherein the source-active register message further indicates whether the multicast stream is active or withdrawn at the ingress routing device; updating, by the central routing device and based on the source-active register message, state information for multicast streams that are active at the ingress routing device, wherein if the source-active register message indicates that the multicast stream is active, the central routing device adds the source address and the identifier to the state information, and wherein if the source-active register message indicates that the multicast stream is withdrawn, the central routing device removes the source address and the identifier from the state information; and after receiving the source-active register message, sending, by the central routing device and to the ingress routing device using the targeted neighbor connection, a list-of-receivers register message that specifies an egress routing device and at least the identifier that is associated with the multicast stream, wherein the list-of-receivers register message further indicates whether or not the egress routing device requests receipt of data associated with the multicast stream. exchanging, by a central routing device and with an ingress routing device that is communicatively coupled to at least one source device (2, 4), a plurality of targeted hello messages to establish a targeted neighbor connection between the central routing device and the ingress routing device, wherein the targeted neighbor connection comprises a reliable transport connection, and wherein exchanging the plurality of targeted hello messages comprises: receiving, by the central routing device and from the ingress routing device, a first targeted hello message comprising a first unicast message that is addressed to the central routing device; and sending, by the central routing device and to the ingress routing device, a second targeted hello message to acknowledge receipt of the first targeted hello message, wherein the second targeted hello message comprises a second unicast message that is addressed to the ingress routing device; receiving, by the central routing device and from the ingress routing device, a first targeted hello message comprising a first unicast message that is addressed to the central routing device; and sending, by the central routing device and to the ingress routing device, a second targeted hello message to acknowledge receipt of the first targeted hello message, wherein the second targeted hello message comprises a second unicast message that is addressed to the ingress routing device; receiving, by the central routing device and from the ingress routing device using the targeted neighbor connection, a source-active register message that specifies a source address and an identifier that are collectively associated with a multicast stream provided by the at least one source device (2, 4), wherein the source-active register message further indicates whether the multicast stream is active or withdrawn at the ingress routing device; updating, by the central routing device and based on the source-active register message, state information for multicast streams that are active at the ingress routing device, wherein if the source-active register message indicates that the multicast stream is active, the central routing device adds the source address and the identifier to the state information, and wherein if the source-active register message indicates that the multicast stream is withdrawn, the central routing device removes the source address and the identifier from the state information; and after receiving the source-active register message, sending, by the central routing device and to the ingress routing device using the targeted neighbor connection, a list-of-receivers register message that specifies an egress routing device and at least the identifier that is associated with the multicast stream, wherein the list-of-receivers register message further indicates whether or not the egress routing device requests receipt of data associated with the multicast stream.