Editing Protocol-Independent Multicast (section)

==Versions==
There are two PIM versions. The versions are not directly compatible though may coexist on the same network. Network equipment may implement both versions. PIMv2 has the following improvements over PIMv1: A single RP is used per group. RP discovery is accomplished by a '''Bootstrap Router''' (BSR). Groups are either sparse or dense mode; Interfaces can be either. General improvements to protocol flexibility and efficiency.<ref name="Cisco Multicast"/>{{rp|59}}