A、Configure the no ip subnet-zero command on R1,R2,and R3.
B、Dynamic routing protocols such as RIPv2 cannot be used across Frame Relay networks.
C、Configure the S0/0 interface on R1 as two subinterfaces and configure point-to-point links to R2 and R3.
D、Change the 172.16.2.0/25 and 172.16.2.128/25 subnetworks so that at least two bits are borrowed from the last octet.
E、Change the network address configuration to eliminate the discontiguous 172.16.2.0/25 and 172.16.2.128/25 subnetwork.