Question

OSPF network where DR & BDR elections are performed -

A) Point-to-Point
B) Broadcast
C) Non-Broadcast
D) Point-to-Multipoint

Answer 1

In OSPF, Designated Router (DR) and Backup Designated Router (BDR) elections occur in Broadcast and Non-Broadcast networks. These elections are crucial in reducing routing protocol traffic and optimizing information exchange. Point-to-Point and Point-to-Multipoint network types do not conduct DR and BDR elections due to their topology.

Step-by-step explanation:

Open Shortest Path First (OSPF) is a routing protocol used in Internet Protocol (IP) networks. In OSPF, Designated Router (DR) and Backup Designated Router (BDR) elections occur in specific network types. The purpose of having a DR and BDR is to optimize the process of information exchange and reduce the amount of routing protocol traffic. DR and BDR elections are performed in networks operating in a Broadcast mode or a Non-Broadcast mode. Broadcast networks include typical Ethernet environments where many devices can receive packets sent to a broadcast address. Non-Broadcast networks include environments where broadcast is not inherently supported, and explicit configurations are needed for OSPF to operate correctly.

Here is a breakdown of OSPF network types and their relation to DR and BDR elections:

• Broadcast networks: This is the most common scenario where DR and BDR elections take place. All routers on a LAN segment will participate in the election process.
• Non-Broadcast networks: These include frame relay or Asynchronous Transfer Mode (ATM) networks, where multicast or broadcast is not inherently supported. DR and BDR elections are still used to reduce the number of adjacencies.
• Point-to-Point networks: There is no DR/BDR election in point-to-point networks because there are only two routers that can form an adjacency directly without a DR/BDR.
• Point-to-Multipoint networks: Similar to point-to-point networks, no DR/BDR election takes place because the network is treated as a collection of point-to-point links.

In conclusion, the OSPF network types where DR and BDR elections are performed are Broadcast and Non-Broadcast networks.

Answer 2

The DR & BDR elections in an OSPF network are performed in Point-to-Multipoint networks. The correct option is D.

Step-by-step explanation:

The subject of this question is OSPF network. OSPF (Open Shortest Path First) is a routing protocol used in computer networks to determine the best path for data packets to travel.

The correct answer to the question is Point-to-Multipoint (D). In OSPF networks, the DR (Designated Router) and BDR (Backup Designated Router) elections are performed in Point-to-Multipoint networks.

For example, in a network where multiple routers are connected to a single hub, the hub acts as the DR and the other routers act as BDRs. This allows for efficient routing and better network performance. Hence, D is the correct option.