The system can work normally with default PIM-DM parameters. You are also allowed to adjust parameters related to neighbor discovery, prune, state refresh, graft, and assert according to specific scenarios. In addition, you can configure various filtering policies and the PIM silent function to enhance the PIM-DM security.
You can configure the Keepalive period of a multicast source and the filtering rules based on multicast sources.
You can set the following control parameters:
The interval for sending Hello messages
The period for keeping neighbors reachable
Whether the Hello messages without the Generation ID option are received
The maximum delay for triggering Hello messages
Neighbor filtering function: An interface sets up neighbor relationships with only the addresses matching the filtering rules and deletes the neighbors unmatched with the filtering rules
You can adjust the following control parameters for pruning:
The interval for keeping the Prune state of the downstream interface
The delay from the time when the current FW receives a Prune message from a downstream FW to the time when the current FW performs the prune action in the LAN
The period for overriding the prune action
You can enable or disable State-Refresh, set the interval for sending PIM State-Refresh messages, set the minimum interval for receiving the next State-Refresh message, and set the TTL value for forwarding State-Refresh messages on the FW directly connected to the source.
You can set the interval for retransmitting Graft messages.
You can set the period for a FW to retain the Assert state. The FW that fails in the election prevents the downstream interface from forwarding multicast data during this period. After the period expires, the downstream interface continues to forward multicast data.
Some hosts may send a large number of malicious PIM Hello messages, which results in the suspension of the FW. The PIM Silent function can then be configured on the interfaces connected to hosts to protect the FW.
In multi-instance applications, multicast FWs need to maintain the PIM neighbor list and multicast routing table for different VPN instances and keep the information independent among multiple instances.
When a FW receives a multicast data packet, the FW needs to distinguish the VPN instance to which the packet belongs and forward the packet based on the multicast routing table of the specific VPN instance, or create a PIM multicast routing entry of the VPN instance.