(Optional) Setting a Switchback Delay for IGMP Proxy Interfaces

Context

After a primary IGMP proxy interface recovers, multicast routing entries are updated. If the primary IGMP proxy interface fails again during an entry update, multicast traffic may be lost. To resolve such issues in primary IGMP proxy interface flapping scenarios, set a switchback delay for IGMP proxy interfaces. The multicast routing entry update process then starts only after the specified switchback delay expires. The switchback delay configured in the IGMP view takes effect on all interfaces, and the switchback delay configured in the interface view takes effect only on that interface.

Procedure

Set a switchback delay for all interfaces.
1. Run system-view
  The system view is displayed.
2. Run multicast routing-enable
  The multicast routing function is enabled.
3. Run igmp [ vpn-instance vpn-instance-name ]
  The IGMP view is displayed.
4. Run proxy reroute delay { delay-time | never }
  The switchback delay is set for IGMP proxy interfaces in the public network instance.
  
  By default, all IGMP proxy interfaces on a switch enter the switchback state without a delay when the switchback trigger conditions are met.
Set a switchback delay for a specified interface.
1. Run system-view
  The system view is displayed.
2. Run multicast routing-enable
  The multicast routing function is enabled.
3. Run interface interface-type interface-number
  The interface view is displayed.
4. (Optional) On an Ethernet interface, run undo portswitch
  The interface is switched to Layer 3 mode.
  
  By default, an Ethernet interface works in Layer 2 mode.
  
  Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
5. Run igmp proxy reroute delay { delay-time | never }
  The switchback delay is set for the specified IGMP proxy interface.

Follow-up Procedure

If you want all IGMP proxy interfaces to enter the switchback state immediately when the switchback trigger conditions are met, run the igmp proxy [ vpn-instance vpn-instance | all-instance ] interface [ interface-type interface-number ] reroute command in the user view to delete the switchback delay of IGMP proxy interfaces.