Configuring IPv4 PIM Silent

Pre-configuration Tasks

Before configuring PIM Silent, complete the following task:

Configure a unicast routing protocol to ensure normal unicast routing on the network.
Enable PIM-SM.

Context

On the access layer, if the PIM protocol is enabled on the interfaces directly connected to user hosts, the interfaces can establish PIM neighbor relationships to process various PIM packets. The configuration, however, brings security risks. When a host maliciously sends many PIM Hello messages, the device may break down.

To prevent the preceding case, you can set the state of the device interface to PIM silent. When the interface is in PIM silent state, the interface is disabled from receiving and forwarding any PIM packet. All PIM neighbors and PIM state machines on the interface are deleted. The interface functions as the static DR and immediately takes effect. The PIM silent function does not affect the IGMP function on the interface.

PIM client takes effect on an interface only when the interface is directly connected to a user network segment and when the network segment is connected only to this PIM device.

After you configure PIM silent on an interface, the interface no longer receives or sends any PIM packets and other PIM functions on the interface become invalid. Confirm your action before configuring this function.
If a user network segment is connected to multiple devices and PIM silent is enabled on interfaces of multiple devices, the interfaces become static DRs. This results in multicast faults.

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 pim silent
The PIM silent function is enabled.

Verifying the Configuration

After PIM silent is configured, you can check information about the PIM interface.

Run the display pim [ vpn-instance vpn-instance-name | all-instance ] interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on an interface.