DNS settings shared between Route53 and previous hosting provider

Question

We have a company website at www.example.com and example.com which is hosted at a hosting provider - The NS records here are for the providers name server.

Our API is accessible at api.example.com - this DNS is part of a hosted zone (not a registered domain) on Route53 and it points to a Load Balancer on AWS - The NS records here are AWS's.

I recently inherited this platform and need to add a new record. I can't seem to find the relationship between our registered domain name (at the hosting provider) and our route53 service. I initially thought the NS records at our hosting provider are updated to cater for AWS according to their docs here: https://aws.amazon.com/route53/faqs/

If your domain name is not managed by Route 53, you will need to inform the registrar with whom you registered your domain name to update the name servers for your domain to the ones associated with your hosted zone. If your domain name is managed by Route 53 already, your domain name will be automatically associated with the name servers hosting your zone.

As I mentioned however, the NS records at the hosting provider is their own. Where else can I start looking for the link between our provider and Route 53?

Answer 1

That should mean that there are NS records for your subdomain at your main DNS host. Your DNS heirarchy should look like:

• Domain registrar: NS records for example.com to main DNS host
  • Main DNS Host:
    • A record for example.com
    • A or CNAME record for www.example.com
    • NS records for api.example.com to route53
      • Route53: ALIAS records for api.example.com to the load balancer

You can verify this by using dig on the command line which should show you the various records. Particularly, you want to see the NS records for api.example.com:

dig NS api.example.com