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Route 53

✅ What is AWS Route 53?

AWS Route 53 is a scalable and highly available Domain Name System (DNS) web service that:

  • Translates domain names (e.g., example.com) into IP addresses (e.g., 192.0.2.1)

  • Provides domain registration

  • Enables health checks and failover

  • Supports traffic flow policies

🚀 Core Features

Feature Description
Domain Registration Buy and manage domain names directly from AWS.
DNS Service Manage public or private DNS records.
Health Checks Automatically monitor endpoints (like EC2, ELB, etc.).
Traffic Flow Visual traffic routing across multiple AWS Regions.
Routing Policies Use latency, geolocation, failover, and more.
Private Hosted Zones Internal DNS management within a VPC.

🧭 Routing Policies

Policy Name Purpose
Simple Basic A/AAAA record routing.
Weighted Split traffic based on weight percentages.
Latency-based Route users to the lowest-latency region.
Failover Route traffic to a backup resource if the primary fails.
Geolocation Route based on user's geographical location.
GeoProximity Route based on geographic region with bias adjustments (Traffic Flow).
Multivalue Answer Return multiple healthy records (like round robin with health check).

🛠️ Step-by-Step Tutorial

🟢 1. Register a Domain (Optional)

# Via AWS Console > Route 53 > Domain Registration

🟢 2. Create a Hosted Zone

  1. Open Route 53 > Hosted Zones

  2. Click Create hosted zone

  3. Enter domain name (e.g., myapp.example)

  4. Choose Public or Private Hosted Zone

  5. Create zone → You’ll get NS and SOA records by default

🟢 3. Add Record Sets

Record Type Description Example
A / AAAA Maps domain to IP (IPv4/IPv6) A -> 54.123.45.67
CNAME Maps domain to another domain www.example.com -> example.com
MX Email routing 10 mail.example.com
TXT For SPF, DKIM, verification "v=spf1 include:..."
Alias Points to AWS resources like ELB, S3 Alias to s3-website URL

🧪 Use Cases & Practical Labs

✅ Practical 1: Point a Domain to EC2 Instance

  1. Create EC2 and note its public IP.

  2. Create an A record in your Hosted Zone.

    Name: myapp.example.com
Type: A
Value: <EC2 IP>
TTL: 300

  3. Test via curl http://myapp.example.com

✅ Practical 2: Create Weighted Routing Between 2 EC2s

  1. Launch two EC2 instances in different AZs.

  2. Create two A records:

    • A -> EC2-1 (Weight: 80)

    • A -> EC2-2 (Weight: 20)

  3. Test using dig and refresh to observe weighted traffic.

✅ Practical 3: Failover Routing with Health Checks

  1. Create two EC2s: Primary and Secondary.

  2. Create Route 53 Health Check on Primary EC2.

  3. Create two A records:

    • Primary: Failover = Primary

    • Secondary: Failover = Secondary

  4. Simulate a failure by stopping the primary EC2.

✅ Practical 4: Latency-Based Routing Between Regions

  1. Create EC2s in us-east-1 and ap-south-1.

  2. Add A records with latency routing.

  3. Test using VPN or simulate latency using curl + --resolve.

✅ Practical 5: Internal DNS with Private Hosted Zones

  1. Create a Private Hosted Zone for your VPC (e.g., internal.local)

  2. Create records like api.internal.local → Private IP

  3. Test from EC2 inside the VPC using dig api.internal.local

🔗 Common Integrations

Service Integration Type
ALB/NLB Alias records to load balancer DNS names
S3 Static website hosting with Alias to S3 bucket
CloudFront CNAME + Alias to CloudFront distribution
ECS/EKS Domain routing to Fargate or Kubernetes services
ACM/SSL Use Route 53 for DNS validation for SSL certs

📈 Monitoring and Logging

  • CloudWatch Metrics from Route 53 Health Checks

  • Query Logging: Enable for Hosted Zones (stored in CloudWatch Logs or S3)

  • Logging DNS requests is helpful for security auditing and analytics

🔐 Security Best Practices

  • Use least privilege IAM permissions for Route 53 access.

  • Lock Hosted Zone changes via IAM policies or AWS Service Control Policies.

  • Use MFA for domain transfers or deletions.

  • For internal services, use Private Hosted Zones.

  • Enable Query Logging for DNS monitoring.

❓ Interview Questions

🔹 Basic

  1. What is AWS Route 53 used for?

  2. What are the different record types in Route 53?

  3. What is the difference between a public and private hosted zone?

🔹 Intermediate

  1. Explain how health checks work in Route 53.

  2. Describe the difference between Alias and CNAME.

  3. What is a TTL and how does it impact DNS propagation?

🔹 Advanced

  1. How does latency-based routing determine the best region?

  2. Can you use Route 53 for internal DNS? How?

  3. How do Route 53 health checks differ from ELB health checks?

  4. Explain how Route 53 integrates with CloudFront and ACM for SSL validation.