PIM (Protocol Independent Multicast) is a family of multicast routing protocols. The word independent comes from the fact that PIM does not build a topology of its own, it uses the information from unicast routing protocols to achieve this. There are a number of different PIM flavors: PIM Sparse-Mode, PIM Dense-Mode, Bidirectional PIM and Source Specific PIM. In these lessons, you will find anything that is related to PIM.