300-420 Question 62
Select 3An enterprise network is undergoing a redesign to improve high availability and scalability in the campus core layer. The network architect suggests implementing a Layer 3 Equal-Cost Multi-Path (ECMP) design using multiple core switches. What is the primary advantage of this approach, and what must be considered to ensure effective deployment?
- A
Improves load balancing across multiple paths, reducing congestion.
- B
Requires all core switches to operate with the same vendor-specific protocols to ensure compatibility.
- C
Minimizes latency by dynamically selecting the shortest path for traffic flow.
- D
Requires the implementation of consistent routing protocols and metrics across the core switches.
- E
Eliminates the need for spanning tree in the core layer, simplifying the network topology.
Show answer and explanation
Correct answers: A, D, E
Explanation
Layer 3 ECMP in the campus core layer enhances high availability and scalability by utilizing multiple equal-cost paths for load balancing and redundancy. To ensure effective deployment, routing protocols and metrics need to be consistent across the core switches, and the use of Layer 3 routing eliminates reliance on spanning tree protocols in the core. This approach also simplifies the topology and improves convergence during link failures, making it a preferred design in advanced enterprise campus networks.
- A. Correct.
Correct: ECMP improves load balancing by enabling traffic to use multiple paths simultaneously, reducing bottlenecks.
- B. Incorrect.
Incorrect: ECMP can work across multi-vendor environments as long as standard routing protocols like OSPF or BGP are used. Vendor-specific protocols are not a strict requirement.
- C. Incorrect.
Incorrect: While ECMP does improve path utilization, it does not dynamically select the 'shortest' path. It balances traffic across all equal-cost paths, which may not always result in the shortest latency.
- D. Correct.
Correct: Consistent routing protocols and metrics are essential for ECMP to function correctly. Inconsistent metrics can prevent paths from being considered equal-cost.
- E. Correct.
Correct: By routing traffic at Layer 3, ECMP eliminates the need for spanning tree in the core layer, reducing complexity and improving convergence times.