> For the complete documentation index, see [llms.txt](https://karansingh.gitbook.io/aws-saa-c02/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://karansingh.gitbook.io/aws-saa-c02/virtual-private-cloud-vpc/dns-support-in-your-vpc.md).

# DNS support in your VPC

* Your **VPC has attributes that determine whether instances launched in the VPC receive public DNS** hostnames that correspond to their public IP addresses, and **whether DNS resolution through the Amazon DNS server is supported for the VPC.**

## `enableDnsHostnames`

* **Indicates whether instances with public IP addresses get corresponding public DNS hostnames**.

* If this attribute is `true`, instances in the VPC get public DNS hostnames, but only if the `enableDnsSupport` attribute is also set to `true`.

## `enableDnsSupport`:

* **Indicates whether the DNS resolution is supported**.

* If this attribute is `false`, the Amazon Route 53 Resolver server that resolves public DNS hostnames to IP addresses is not enabled.

* If this attribute is `true`, queries to the Amazon provided DNS server at the 169.254.169.253 IP address, or the reserved IP address at the base of the VPC IPv4 network range plus two will succeed.

## Conditions

* **If both are `true`:**
  * **Instances with a public IP address receive corresponding public DNS hostnames**.
  * The Amazon Route 53 Resolver server can resolve Amazon-provided private DNS hostnames.<br>
* **If either or both of the attributes is `false`:**
  * **Instances with a public IP address do not receive corresponding public DNS hostnames**.
  * The Amazon Route 53 Resolver cannot resolve Amazon-provided private DNS hostnames.<br>
* **If you use custom DNS domain names** defined in a private hosted zone in Amazon Route 53, you **must set both the `enableDnsHostnames` and `enableDnsSupport` attributes to `true`**.