Exam 100-101 Topic 7 Question 46 Discussion
Actual exam question for Facebook's 100-101 exam
Question #: 46
Topic #: 7
Question #: 46
Topic #: 7
The internetwork infrastructure of company XYZ consists of a single OSPF area as shown in the graphic. There is concern that a lack of router resources is impeding internetwork performance. As part of examining the router resources, the OSPF DRs need to be known. All the router OSPF priorities are at the default and the router IDs are shown with each router.

Which routers are likely to have been elected as DR? (Choose two.)

Which routers are likely to have been elected as DR? (Choose two.)
Suggested Answer: D,F Vote an answer
There are 2 segments on the topology above which are separated by Corp-3 router. Each
segment will have a DR so we have 2 DRs.
To select which router will become DR they will compare their router-IDs. The router with
highest (best) router-ID will become DR. The router-ID is chosen in the order below:
+
The highest IP address assigned to a loopback (logical) interface.
+
If a loopback interface is not defined, the highest IP address of all active router's physical interfaces will be chosen.
In this question, the IP addresses of loopback interfaces are not mentioned so we will consider IP addresses of all active router's physical interfaces. Router Corp-4 (10.1.40.40) & Branch-2 (10.2.20.20) have highest "active" IP addresses so they will become DRs.
segment will have a DR so we have 2 DRs.
To select which router will become DR they will compare their router-IDs. The router with
highest (best) router-ID will become DR. The router-ID is chosen in the order below:
+
The highest IP address assigned to a loopback (logical) interface.
+
If a loopback interface is not defined, the highest IP address of all active router's physical interfaces will be chosen.
In this question, the IP addresses of loopback interfaces are not mentioned so we will consider IP addresses of all active router's physical interfaces. Router Corp-4 (10.1.40.40) & Branch-2 (10.2.20.20) have highest "active" IP addresses so they will become DRs.
by Harriet at Oct 05, 2026, 03:23 PM
0
0
0
10
Comments
Upvoting a comment with a selected answer will also increase the vote count towards that answer by one. So if you see a comment that you already agree with, you can upvote it instead of posting a new comment.
Report Comment
Commenting
You can sign-up / login (it's free).