Learn which OSPF network type requires Designated Router (DR) and Backup Designated Router (BDR) election for the CCNA 200-301 exam. Understand how DR and BDR reduce overhead in broadcast multi-access networks like Ethernet LANs.
Table of Contents
Question
What type of OSPF network type requires a DR (Designated Router) and BDR (Backup Designated Router)?
A. Point-to-Point
B. Broadcast
C. Non-Broadcast Multi-Access
D. Loopback
E. Stub
Answer
B. Broadcast
Explanation
In OSPF Broadcast networks, a Designated Router (DR) and Backup Designated Router (BDR) reduce overhead by managing neighbor relationships.
OSPF elects a Designated Router (DR) and Backup Designated Router (BDR) on broadcast network types, such as Ethernet LANs. In these multi-access environments, multiple routers may be present on the same segment. Without a DR and BDR, every router would need to form a full adjacency with every other router, causing excessive overhead and unnecessary flooding of link-state advertisements (LSAs). The DR acts as a central point for exchanging OSPF routing information, while the BDR serves as a standby in case the DR fails. This election process only occurs on broadcast and non-broadcast multi-access networks, but is a default requirement for broadcast networks.
Cisco Certified Network Associate CCNA 200-301 certification exam practice question and answer (Q&A) dump with detail explanation and reference available free, helpful to pass the Cisco Certified Network Associate CCNA 200-301 exam and earn Cisco Certified Network Associate CCNA 200-301 certification.