Migrating DNS service for a subdomain to Amazon Route 53 without migrating the parent domain - Amazon Route 53
Deciding which procedures to use for creating a subdomainCreating a hosted zone for the subdomainGetting your current DNS configuration from your DNS service providerCreating recordsChecking the status of your changes (API only)Updating your DNS service with name server records for the subdomain

Migrating DNS service for a subdomain to Amazon Route 53 without migrating the parent domain

You can migrate a subdomain to use Amazon Route 53 as the DNS service without migrating the parent domain from another DNS service.

The process has the following basic steps:

  1. Figure out whether you should even be using this procedure.

  2. Create a Route 53 hosted zone for the subdomain.

  3. Get the current DNS configuration from the current DNS service provider for the parent domain.

  4. Add records for the subdomain to your Route 53 hosted zone.

  5. API only: Confirm that your changes have propagated to all Route 53 DNS servers.

    Note

    Currently, the only way to verify that changes have propagated is to use the GetChange API action. Changes generally propagate to all Route 53 name servers within 60 seconds.

  6. Update the DNS configuration with the DNS service provider for the parent domain by adding name server records for the subdomain.

Deciding which procedures to use for creating a subdomain

The procedures in this topic explain how to perform an uncommon operation. If you're already using Route 53 as the DNS service for your domain and you just want to route traffic for a subdomain, such as www.example.com, to your resources, such as a web server running on an EC2 instance, see Routing traffic for subdomains.

Use this procedure only if you're using another DNS service for a domain, such as example.com, and you want to start using Route 53 as the DNS service for an existing subdomain of that domain, such as www.example.com.

Creating a hosted zone for the subdomain

If you want to migrate a subdomain from another DNS service to Amazon Route 53 but you don't want to migrate the parent domain, start by creating a hosted zone for the subdomain. Route 53 stores information about your subdomain in the hosted zone.

For information about how to create a hosted zone using the Route 53 console, see Creating a public hosted zone.

Getting your current DNS configuration from your DNS service provider

To simplify the process of migrating an existing subdomain to Route 53, get the current DNS configuration for the domain from the DNS service provider that is currently servicing the domain. You can use this information as a basis for configuring Route 53 as the DNS service for the subdomain.

What you ask for and the format that it comes in depends on which company you're currently using as your DNS service provider. Ideally, they'll give you a zone file, which contains information about all of the records in your current configuration. (Records tell DNS how you want traffic to be routed for your domains and subdomains. For example, when someone enters your domain name in a web browser, do you want traffic to be routed to a web server in your data center, to an Amazon EC2 instance, to a CloudFront distribution, or to some other location?) If you can get a zone file from your current DNS service provider, you can edit the zone file to remove the records that you don't want to migrate to Amazon Route 53. Then you can import the remaining records into your Route 53 hosted zone, which greatly simplifies the process. Try asking customer support for your current DNS service provider how to get a zone file or a records list.

Creating records

Using the records that you got from your current DNS service provider as a starting point, create corresponding records in the Amazon Route 53 hosted zone that you created for the subdomain. The records that you create in Route 53 will become the records that DNS uses after you delegate responsibility for the subdomain to Route 53, as explained in Updating your DNS service with name server records for the subdomain, later in the process.

Important

Do not create additional name server (NS) or start of authority (SOA) records in the Route 53 hosted zone, and do not delete the existing NS and SOA records.

To create records using the Route 53 console, see Working with records. To create records using the Route 53 API, use ChangeResourceRecordSets. For more information, see ChangeResourceRecordSets in the Amazon Route 53 API Reference.

Checking the status of your changes (API only)

Creating a new hosted zone and changing records take time to propagate to the Route 53 DNS servers. If you used ChangeResourceRecordSets to create your records, you can use the GetChange action to determine whether your changes have propagated. (ChangeResourceRecordSets returns a value for ChangeId, which you can include in a subsequent GetChange request. ChangeId is not available if you created the records by using the console.) For more information, see GET GetChange in the Amazon Route 53 API Reference.

Note

Changes generally propagate to all Route 53 name servers within 60 seconds.

Updating your DNS service with name server records for the subdomain

After your changes to Amazon Route 53 records have propagated (see Checking the status of your changes (API only)), update the DNS service for the parent domain by adding NS records for the subdomain. This is known as delegating responsibility for the subdomain to Route 53. For example, suppose the parent domain example.com is hosted with another DNS service and you're migrating the subdomain test.example.com to Route 53. You must create a hosted zone for test.example.com and update the DNS service for example.com with the NS records that Route 53 assigned to the new hosted zone for test.example.com.

Perform the following procedure.

  1. Using the method provided by your DNS service, back up the zone file for the parent domain.

  2. If the previous DNS service provider for the domain has a method to change the TTL settings for their name servers, we recommend that you change the settings to 900 seconds. This limits the time during which client requests will try to resolve domain names using obsolete name servers. If the current TTL is 172800 seconds (two days), which is a common default setting, you still need to wait two days for resolvers and clients to stop caching DNS records using the previous TTL. After the TTL settings expire, you can safely delete the records that are stored at the previous provider and make changes only to Route 53.

  3. In the Route 53 console, get the name servers for your Route 53 hosted zone:

    1. Sign in to the AWS Management Console and open the Route 53 console at https://console.aws.amazon.com/route53/.

    2. In the navigation pane, click Hosted zones.

    3. On the Hosted zones page, choose the radio button (not the name) for the hosted zone, then choose View details.

    4. On the details page for the hosted zone, choose Hosted zone details.

    5. Make note of the four servers listed for Name servers.

    Alternatively, you can use the GetHostedZone action. For more information, see GetHostedZone in the Amazon Route 53 API Reference.

  4. Using the method provided by the DNS service of the parent domain, add NS records for the subdomain to the zone file for the parent domain. Give the NS records the same name as the subdomain. For the values in the NS records, specify the four Route 53 name servers that are associated with the hosted zone that you created in Step 2. Note that different DNS services use different terminology. You might need to contact technical support for your DNS service to learn how to perform this step.

    Important

    Do not add a start of authority (SOA) record to the zone file for the parent domain. Because the subdomain will use Route 53, the DNS service for the parent domain is not the authority for the subdomain.

    If your DNS service automatically added an SOA record for the subdomain, delete the record for the subdomain. However, do not delete the SOA record for the parent domain.

    Depending on the TTL settings for the name servers for the parent domain, the propagation of your changes to DNS resolvers can take 48 hours or more. During this period, DNS resolvers may still answer requests with the name servers for the DNS service of the parent domain. In addition, client computers may continue to have the previous name servers for the subdomain in their cache.

  5. After the registrar's TTL settings for the domain expire (see Step 2), delete the following records from the zone file for the parent domain:

    • The records that you added to Route 53 as described in Creating records.

    • Your DNS service's NS records. When you are finished deleting NS records, the only NS records in the zone file will be the ones that you created in Step 4.