A. Improves convergence of the multicast network due to enhanced RPF checks
B. Simplifies the number of control plane protocols over other RP redundancy methods
C. Eliminates the use of Protocol Independent Multicast （PIM） in the topology
D. Increases the administrative distances in Multicast Source Discovery Protocol （MSDP） configuration

A. The peer router 10.1.1.2 has PIM disabled on its interface connecting to Ethernet1/18.
B. The peer router 10.1.1.2 has the wrong PIM password configured on its interface connecting to Ethernet1/18.
C. The local router 10.1.1.1 has the wrong PIM password configured on Ethernet1/18.
D. The peer router 10.1.1.2 does not have PIM hello authentication enabled on its interface connecting to Ethernet1/18.
E. The local router 10.1.1.1 does not have PIM hello authentication enabled for Ethernet1/18.