DELL S50V User Manual

Multicast Features | 669

Rate Limit IGMP Join Requests

If you expect a burst of IGMP Joins, protect the IGMP process from overload by limiting that rate at which 
new groups can be joined using the command 

 from INTERFACE mode. Hosts 

whose IGMP requests are denied will use the retry mechanism built-in to IGMP so that they’re 
membership is delayed rather than permanently denied.

View the enable status of this feature using the command 

 from EXEC Privilege 

mode.

Prevent a PIM Router from Forming an Adjacency

To prevent a router from participating in Protocol Independent Multicast (PIM) (for example, to configure 
stub multicast routing), use the 

 command from INTERFACE mode.

Prevent a Source from Registering with the RP

Use the command 

 from CONFIGURATION mode to prevent a source from 

transmitting to a particular group. This command prevents the PIM source DR from sending register 
packets to RP for the specified multicast source and group; if the source DR never sends register packets to 
the RP, no hosts can ever discover the source and create an SPT to it.

, Source 1 and Source 2 are both transmitting packets for groups 239.0.0.1 and 239.0.0.2. R3 

has a PIM register filter that only permits packets destined for group 239.0.0.2. An entry is created for 
group 239.0.0.1 in the routing table, but no outgoing interfaces are listed. R2 has no filter, so it is allowed 
to forward both groups. As a result, Receiver 1 receives only one transmission, while Receiver 2 receives 
duplicate transmissions.