Filtering Multicast Messages
Multicast sources and routers generate a considerable number of control messages, especially when using PIM sparse mode. These messages form distribution trees, locate RPs and DRs, and transition from one type of tree to another. In most cases, this multicast messaging system operates transparently and efficiently. However, in some configurations, more control over the sending and receiving of multicast control messages is necessary.
You can configure two types of multicast filtering to control the sending and receiving of multicast control messages.
This section discusses three types of multicast filtering. The last two require configuration:
