Dell S6100 Configuration Manual page 559

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 creating a state based on multicast source and/or group.
ip pim join-filter
NOTE: When you configure a join filter, it is applicable for both ingress and egress flows. There is no option to specify in
or out parameters while configuring a join filter.
Multicast Features 559