200-301 Question 341
Single answerIn an OSPF broadcast network, a router is being added to a segment where a Designated Router (DR) and Backup Designated Router (BDR) have already been elected. How does the new router participate in the DR/BDR election process?
- A
The new router will immediately initiate a new election and attempt to become the DR.
- B
The new router will only participate in the DR/BDR election if the current DR or BDR becomes unavailable.
- C
The new router will passively accept the roles of the current DR and BDR without participating in the election process.
- D
The new router will send a Hello packet to declare itself as the new DR if it has the highest priority.
Show answer and explanation
Correct answer: B
Explanation
In OSPF broadcast networks, the DR and BDR are elected during the initial setup based on priority and Router ID. Once a DR and BDR are elected, they maintain their roles unless one of them becomes unavailable. A new router joining the network will not force a re-election but will instead follow the existing DR/BDR without disrupting the topology.
- A. Incorrect.
Incorrect. Once DR/BDR are elected, an election is not reinitiated by adding a new router unless the DR/BDR roles are vacated.
- B. Correct.
Correct. The new router will only participate in the election process if the current DR or BDR becomes unavailable.
- C. Incorrect.
Incorrect. While the new router does not initiate an election, it still exchanges Hello packets and establishes adjacencies with DR and BDR.
- D. Incorrect.
Incorrect. A router does not unilaterally declare itself as the new DR, even if it has the highest priority. DR/BDR roles change only if the current roles become unavailable.