Disabling Forwarding of State-Refresh Messages
Context
Pruned interfaces can resume multicast forwarding when the prune timer expires, even though no downstream devices need to receive multicast data. To prevent this problem, the PIM device directly connected to a multicast source sends State-Refresh messages at intervals to update the state of (S, G) entries. A State-Refresh message is propagated to downstream devices hop by hop to reset prune timers on all the PIM devices. Interfaces that do not need to forward multicast data remain pruned.
By default, all PIM devices can forward State-Refresh messages. Disable forwarding of State-Refresh messages if you want multicast data to be flooded on the entire network in every flood-prune process and to allow pruned interface to resume multicast forwarding.
Disabling forwarding of State-Refresh messages is not recommended because State-Refresh messages conserve network resources.
Procedure
- Run system-view
The system view is displayed.
- Run interface interface-type interface-number
The interface view is displayed.
- (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.
- Run undo pim state-refresh-capable
Forwarding of State-Refresh messages is disabled on the interface.
By default, forwarding of State-Refresh messages is enabled on the interface.
To enable the interface to forward State-Refresh messages again, run the pim state-refresh-capable command.