Refer to the exhibit.
Why are two OSPF designated routers identified on Core_Router?
A.
Core_Router is connected to more than one multiaccess network.
B.
The router at 208.149.23.130 is a secondary DR in case the primary fails.
C.
Two router IDs have the same OSPF priority and are therefore tied for DR election
D.
The DR election is still underway and there are two contenders for the role.
Explanation:
OSPF neighbors process multicast hello packets upon multicast address 224.0.0.5 to find
neighbors dynamically. Default hello packets sending interval is 10 seconds, and dead interval is
40 seconds. In multi-access broadcasting network (such as Ethernet Net and Token Ring),
DR/BDR elections are needed. When electing DR/BDR, hello packets priority is considered, the
highest priority is DR, then BDR. Default priority is 1. In the circumstances when Priority is the
same, RID will be considered, the highest rating RID is DR, and then BDR. When you set the
priority 0, OSPF router can not become DR/BDR, it will only turn into DROTHER. From the above
OSPF neighbors table, we learn that Ethernet1 and Ethernet0 select DR correspondingly, and
Core_Router is connected two multi-access networks.