Issue Description

Streaming Media Server----------->XG0/0/5(S6720)XG0/0/23 &XG0/0/24-------->XG0/0/1&XG0/0/2(S5720)--------EDGE QUAM(Multicast feed receiver)

There are one of the ISP1 and ISP2 providing Data (Internet) and CATV services . Recently we had procured Huawei switches for us to carry and deliver both Data and Multicast services at various part. While doing implementation we had observed that if primary link goes down it took 30 to 40-Seconds for fail-over for Multicast stream to recover, due to this videos stream stops for 40-Seconds and surprisingly for data (Unicast) there is no delay observed with only single packet loss. Secondly if primary link get restored it also takes same time.<?xml:namespace prefix = "o" />




                                                Alarm InformationNone
                                                Handling Process1. The primary path and secondary path are independent, did not use eth-trunk interface binding;
2. Vlan igmp snooping is enabled on switches, and multicast traffic flows through the active path. When the primary path is down, the secondary path port will become a member port and the user rejoins the multicast group.
3. The topology of the Layer 2 network changes on the network, the forwarding path of multicast packets changes, and the multicast query regenerates. The upstream querier sends Query messages within a certain interval (the default interval is 60 seconds). After the Layer 2 network convergence is complete, the downstream device does not receive the Query packet immediately. Therefore, the multicast forwarding path cannot be quickly switched. The multicast switching time tested by the customer may be 30 to 40 seconds.
4. This scenario can be solved by configuring the fast forwarding function of the multicast forwarding path when the STP topology changes. When the STP topology changes, this function can rapidly add the interface in the forwarding state on the device to the router port, thus guiding the multicast data flow to quickly switch to the new forwarding path.
                                                Root CauseThe network configuration or design of multicast is unreasonable
                                                Solution
1. The first way:
Configuring  the following command on S6720:
System-view
igmp-snooping fast-switch enable
2. The second way:
Currently, it is recommended to implement fast switchover of multicast traffic by binding eth-trunk.

                                                SuggestionsLink protection can be better implemented by configuring the eth-trunk link