Which of the following network types have a designated router and a backup designated router assigned?

Question: Which of the following network types have a designated router and a backup designated router assigned?

[A].

1, 2 and 3

[B].

1 and 3

[C].

3 and 4

[D].

All of the above

Answer: Option B

Explanation:

No DR is assigned on any type of point-to-point link. No DR/BDR is assigned on the NBMA point-to-multipoint due to the hub/spoke topology. DR and BDR are elected on broadcast and non-broadcast multi-access networks. Frame Relay is a non-Broadcast Multi-Access (NBMA) network by default.