Route 53 Latency-Based Routing for Multi-Region Active-Active
A company is designing a multi-Region architecture with active-active failover for a web application. The application uses Application Load Balancers (ALBs) in two AWS Regions. Traffic must be routed to the closest healthy Region with automatic failover. Which AWS service should be used to route traffic?
Quick Answer
The answer is Amazon Route 53 with latency-based routing and health checks. This combination is correct because latency-based routing directs user traffic to the AWS Region that provides the lowest network latency, while integrated health checks continuously monitor the health of each Application Load Balancer endpoint and automatically reroute traffic away from an unhealthy Region, enabling true active-active failover across multiple Regions. On the AWS Certified Advanced Networking Specialty ANS-C01 exam, this scenario tests your understanding of how to implement multi-region active-active architectures using DNS-based routing policies, and a common trap is confusing Global Accelerator’s anycast approach with Route 53’s latency-based routing—Global Accelerator optimizes the network path but does not perform latency-based DNS routing to the closest healthy Region in the same way. A useful memory tip: think of latency-based routing as “the DNS that picks the fastest lane,” and health checks as the “automatic exit ramp” when a lane is closed.
⚠ Common exam trap
The ANS-C01 exam often tests the distinction between DNS-based routing (Route 53) and anycast-based traffic steering (Global Accelerator), where candidates mistakenly choose Global Accelerator because it provides low-latency routing, but it does not natively support active-active failover between two independent ALBs in different Regions without additional custom logic.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Amazon Route 53 with latency-based routing and health checks
Amazon Route 53 with latency-based routing and health checks is the correct choice because it directs traffic to the AWS Region with the lowest latency for each user, and health checks automatically fail over to the next best healthy Region if an ALB becomes unhealthy. This satisfies the active-active failover requirement without introducing additional caching or anycast complexities.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Network Load Balancer with cross-zone load balancing
Why it's wrong here
NLB operates within a single Region and cannot route traffic across Regions.
- ✗
Amazon CloudFront with multiple origins
Why it's wrong here
CloudFront is a content delivery network, not designed for active-active load balancing with health-check-based failover.
- ✓
Amazon Route 53 with latency-based routing and health checks
Why this is correct
Route 53 latency routing directs traffic to the Region with the lowest latency, and health checks automatically fail over to the next best Region.
- ✗
AWS Global Accelerator
Why it's wrong here
Global Accelerator uses anycast IPs and endpoint weights, not latency-based DNS routing.
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Same concept, more angles
4 more ways this is tested on ANS-C01
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company is designing a multi-region active-active architecture with an Application Load Balancer in each region. Which service can route traffic to the closest ALB based on latency?
medium- A.AWS Global Accelerator
- ✓ B.Amazon Route 53 latency-based routing
- C.Application Load Balancer cross-zone load balancing
- D.Amazon CloudFront
Why B: Amazon Route 53 latency-based routing directs traffic to the AWS region that provides the lowest latency for the end user, based on historical latency measurements between the user's ISP and each region. This makes it the correct choice for routing users to the closest Application Load Balancer in a multi-region active-active architecture.
Variation 2. A company is designing a multi-Region Active-Active architecture with an Application Load Balancer (ALB) in us-east-1 and us-west-2. They want to route users to the nearest healthy endpoint using a custom domain name. Which AWS service should they use to accomplish this with the lowest latency and minimal operational overhead?
medium- ✓ A.Use Amazon Route 53 latency-based routing with health checks.
- B.Use Amazon Route 53 geolocation routing policy.
- C.Use AWS Global Accelerator with endpoint groups in each region.
- D.Use Amazon Route 53 weighted routing policy.
Why A: Amazon Route 53 latency-based routing directs user traffic to the AWS region that provides the lowest latency for the end user, based on latency measurements between DNS resolvers and AWS endpoints. Combined with health checks, it automatically routes users away from unhealthy ALBs, meeting the requirement for nearest healthy endpoint with minimal operational overhead since it is a fully managed DNS service with no additional infrastructure to deploy.
Variation 3. A company is designing a multi-region active-active architecture with Amazon Route 53. The application is deployed behind Application Load Balancers (ALBs) in us-east-1 and eu-west-1. The company wants to minimize latency for users and provide automatic failover. Which routing policy should be used?
medium- A.Failover routing policy
- B.Geolocation routing policy
- ✓ C.Latency-based routing policy
- D.Weighted routing policy
Why C: Latency-based routing policy is the correct choice because it directs traffic to the AWS region that provides the lowest latency for the end user, which aligns with the requirement to minimize latency. Additionally, Route 53 automatically performs health checks on the ALBs; if one region's ALB becomes unhealthy, Route 53 routes traffic to the healthy region, providing automatic failover in an active-active architecture.
Variation 4. A company is designing a multi-region architecture with an active-active setup. They need to route traffic to the nearest healthy endpoint. Which AWS service should they use?
medium- A.Application Load Balancer (ALB)
- ✓ B.Amazon Route 53 latency-based routing
- C.AWS Global Accelerator
- D.Amazon CloudFront
Why B: Amazon Route 53 latency-based routing directs traffic to the AWS Region that provides the lowest latency for the end user, based on measurements between the user's DNS resolver and AWS endpoints. It also supports health checks, automatically excluding unhealthy endpoints from the routing pool, which enables an active-active multi-region architecture by routing each request to the nearest healthy endpoint. AWS Global Accelerator also routes to the nearest healthy endpoint but uses anycast IPs at the network layer, making it more suitable for optimizing TCP/UDP traffic rather than general DNS-level routing.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This ANS-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the ANS-C01 exam.