Configuring IPv4 PIM Silent

Pre-configuration Tasks

Context

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. Exercise caution when configuring this function.

On the access layer, if PIM is enabled on the interfaces directly connected to user hosts, the interfaces can establish PIM neighbor relationships to process PIM packets. However, this brings security risks. If a malicious host sends a large number of PIM Hello messages, the device may break down.

To prevent the preceding problem, set the state of these interfaces to PIM silent. An interface in PIM silent state does not receive or forward PIM packets. All PIM neighbors and PIM state machines on the interface are deleted, and the interface immediately becomes a static DR. The PIM silent function does not affect the Internet Group Management Protocol (IGMP) function on the interface.

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

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.