Configure Route 53 hosted zones and records.

Amazon Route 53 is a scalable and highly available Domain Name System (DNS) web service. It effectively connects user requests to infrastructure running in AWS, such as Amazon EC2 instances, elastic load balancers, or S3 buckets, and can also be used to route users to infrastructure outside of AWS. Here’s a guide to configuring Route 53 hosted zones and records, which is particularly useful for those preparing for the AWS Certified SysOps Administrator – Associate (SOA-C02) exam.

Understanding Hosted Zones

A hosted zone is a container that holds information about how you want to route traffic for a domain (such as example.com) and its subdomains. There are two types of hosted zones:

• Public Hosted Zones: Allow you to manage public DNS records for your domain.
• Private Hosted Zones: Allow you to manage DNS records for your domain within one or more Amazon Virtual Private Clouds (VPCs).

How to Create a Route 53 Hosted Zone

Public Hosted Zone:

1. Sign in to the AWS Management Console and open the Route 53 dashboard.
2. Click on “Create Hosted Zone”.
3. Enter the domain name for which you want to create the hosted zone.
4. Select the “Public Hosted Zone” type.
5. Click “Create”.

Private Hosted Zone:

1. Sign in to the AWS Management Console and open the Route 53 dashboard.
2. Click on “Create Hosted Zone”.
3. Enter the domain name for your private zone.
4. Select “Private Hosted Zone” for the type.
5. Associate the zone with the VPC where you want it to be accessible.
6. Click “Create”.

Configuring DNS Records

Once you have your hosted zone, you can begin configuring DNS records. These records include information about how to route traffic for your domain. The most common types include:

• A Record: Maps a domain to an IPv4 address.
• AAAA Record: Maps a domain to an IPv6 address.
• CNAME Record: Maps a domain to another domain name (only for non-root domain names).
• MX Record: Defines mail exchange servers for the domain.
• TXT Record: Stores text information related to the domain.
• NS Record: Specifies the name servers for the hosted zone.

Here’s how you can manage these records within your hosted zone:

1. From the Route 53 dashboard, select the hosted zone for your domain.
2. Click on “Create Record Set”.
3. Enter the details for your DNS record:
   • Name: The domain or subdomain you want to route traffic for (e.g., www.example.com).
   • Type: The type of record you are creating (e.g., A, AAAA, CNAME, MX, TXT, NS).
   • Value: The relevant value for your record type, such as an IP address for A records or a domain name for CNAME records.
4. Set the TTL (Time to Live), which tells DNS resolvers how long to cache the results.
5. Click “Create”.

Important Considerations

• TTL values should be chosen carefully, as this will impact how quickly changes to your DNS records propagate across the internet.
• For a private hosted zone, each Amazon VPC that you want to associate with the zone must be in the same region as the hosted zone.
• Changes to DNS configurations can take time to propagate, depending on TTL values and DNS caching behavior.

Common Use Cases and Examples

Example 1: Routing Traffic to an Amazon EC2 Instance

1. Create an A record.
2. Provide the public IP address of your EC2 instance as the Value.

Example 2: Load Balancing with Route 53

1. Create a CNAME record for www.mywebsite.com.
2. Set the value to the DNS name of your ELB (e.g., my-elb-1234567890.us-west-2.elb.amazonaws.com).

Example 3: Private DNS for an Internal Service

1. For a service accessible only within a VPC, create a Private Hosted Zone and A records that map to the private IP addresses of your resources.

By understanding and effectively managing Route 53 hosted zones and DNS records, SysOps administrators can ensure efficient and reliable access to AWS resources and services. Mastery of these concepts is beneficial for the AWS Certified SysOps Administrator – Associate exam, as domain and subdomain routing are critical components of operating AWS workloads.