| 摘要 |
In one embodiment, a particular multicast-enabled device on a LAN may determine that it is to send a Join message to an upstream multicast-enabled device that is configured to source multicast data into the LAN. As such, the particular device may transmit a Join message to the upstream device, where the Join message may have a Hello Request indication when there are no downstream multicast neighbors for the upstream device in the LAN, or may not have the Hello Request indication if there is at least one downstream multicast neighbor for the upstream device. Specifically, the Hello Request requests that the upstream device transmit Hello messages onto the LAN. Multicast-enabled devices in the LAN may thus transmit Hello messages in response to receiving a Join message having a Hello Request directed to that particular device, that is, transmitting the Hello messages so long as there is interest in receiving them. |
