Adjusting Control Parameters for a Multicast Source

Pre-configuration Tasks

Before setting the parameters for controlling a multicast source, complete the following task:

Context

After a PIM device receives a multicast packet from a multicast source, it starts a timer for the (S, G) entry and sets the timer to the lifetime of the source. If the device receives a packet from the source before the timer expires, it resets the timer. If the device does not receive any multicast packet from the source within the lifetime of the source, it considers the corresponding (S, G) entry invalid and deletes this entry.

You can configure the lifetime of the source. To control multicast traffic or ensure data security, configure source address-based filtering policies on the device so that the device accepts only multicast data allowed by the policies.

Default Settings

Table 1 lists the default settings of control parameters for a multicast source.

**Table 1** Default settings of multicast source control parameters
Parameter	Default Setting
Keepalive period of a multicast source	210s
Source address filtering policy	No policy configured (Multicast data from all sources is accepted.)

Procedure

Run system-view
The system view is displayed.
Run pim [ vpn-instance vpn-instance-name ]
The PIM view is displayed.
Run source-lifetime { interval | infinity } [ group-policy acl-number ]
The lifetime of a multicast source is configured.
Run source-policy acl-number
A multicast source address-based filtering policy is configured.
- If a basic ACL is specified in the command, the allowed multicast packets are specified by the source parameter in the rule configured under the basic ACL. The device forwards only the multicast packets with the source addresses allowed by the filtering policy.
- If an advanced ACL is specified in the command, the allowed multicast packets are specified by source and destination parameters in the rule configured under the advanced ACL. The device forwards only the multicast packets with both source addresses and group addresses allowed by the filtering policy.
- If the specified ACL contains no rule, the device does not forward multicast packets from any sources.
- The source-policy command does not filter the static (S, G) entries and the PIM entries of the Join messages received from private networks.

Verifying the Configuration

Run the following commands to check the PIM routing table.

Run the display pim [ vpn-instance vpn-instance-name | all-instance ] routing-table [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } | outgoing-interface { include | exclude | match } { interface-type interface-number | register | none } | mode { dm | sm | ssm } | flags flag-value | fsm ] ^* [ outgoing-interface-number [ number ] ] command to check detailed information about the PIM routing table.
Run the display pim [ vpn-instance vpn-instance-name | all-instance ] routing-table brief [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } ] ^* command to check brief information about the PIM routing table.