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I have read some of the AWS documents but could not find an exact answer. I am looking to have different domains resolving internally inside the same VPC.

Something like this:

domain1.internal (dns zone Z1)
domain2.internal (dns zone Z2)

Both domains would obviously resolve hosts in the same ip ranges.

Is this possible in AWS and are any potential clashes or pitfalls having this configuration?

Or should I have a single private DNS zone instead as below?

subdomain1.domain.internal
subdomain2.domain.internal
truesamurai
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  • I haven't tried this specific setup (multiple sub-domains), so not an answer, but it should work. Each domain requires its own hosted zone in Route53. Where things might get tricky is creating the sub-domain relationships: you'll have to create a hosted zone for the top-level domain, and and NS records for the sub-domains. But I don't see any reason why that won't work. – Parsifal Jun 11 '22 at 12:28
  • Are you delegating Name Servers for each subdomain? If not, then you can create one Hosted Zone. Subdomains do not require their own zones. I usually do not create delegated zones except when the zone is large or I want separate/independant management. – John Hanley Jun 11 '22 at 22:46

1 Answers1

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By default AWS uses Route 53 for domain resolution. Route 53 provides Private Hosted Zones for internal domains. Private Hosted Zones are tied to VPCs, so they they will resolve domains in the same CIDR ranges.

When you create a Private Hosted Zone, you specify a parent domain. Each hosted zone can have different type of records. NS records are generated by AWS, you don't have to create them manually. In case of other records:

  • You can have an A record, which can be either Alias or non-Alias. This can be the same as the domain name of the hosted zone;
  • You can multiple CNAME records or 'A' records for your subdomains;
  • You can have other records, for other purposes (see record types )

In your case if we take subdomain1.domain.internal and subdomain2.domain.internal:

  • You can have domain.internal as the parent record for the hosted zone and create 2 CNAME or A records for subdomain1 and subdomain2
  • Or you can create separate hosted zones for subdomain1.domain.internal and subdomain2.domain.internal and use A records

The downfall of the first approach is that your hosted zones wont be as granular, meaning that everything which ends with domain.internal will be resolved with this hosted zone. You can override this, by creating other hosted zones with more precise parent domain names (see overlapping namespaces).

The downfall of the second approach is that you will pay for each hosted zone. Private Hosted Zones are relatively cheap.

Ervin Szilagyi
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  • Edit: I did a correction to use `subdomain1.domain.internal` and `subdomain2.domain.internal` as an example, for better understanding. The same can be applied if you create the hosted zone with `internal` as the parent domain. – Ervin Szilagyi Jun 11 '22 at 13:29