Dell S4820T Configuration Manual page 670

Preventing a PIM Router from Processing a Join
To permit or deny PIM Join/Prune messages on an interface using an extended IP access list, use the
following command.
NOTE: Dell Networking recommends not using the ip pim join-filter command on an
interface between a source and the RP router. Using this command in this scenario could cause
problems with the PIM-SM source registration process resulting in excessive traffic being sent to the
CPU of both the RP and PIM DR of the source.
Excessive traffic generates when the join process from the RP back to the source is blocked due to
a new source group being permitted in the join-filter. This results in the new source becoming stuck
in registering on the DR and the continuous generation of user datagram protocol (UDP)-
encapsulated registration messages between the DR and RP routers which are being sent to the
CPU.
• Prevent the PIM SM router from a creating state based on the multicast source and/or group.
ip pim join-filter
NOTE: When you configure a join filter that filter is applicable for both ingress and egress flows.
There is no option to specify in or out parameters while configuring a join filter.
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Multicast Features