How to get Route53 to forward/point to a load balancer in AWS?

Question

I am trying to setup a subdomain in Route53 to point to a load balancer in AWS. (I'm using a load balancer as it seems to be required in order to use the ACM-provided SSL certs)

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This is what I've achieve/attempted so far:

Everything was created in the same AWS account including registration of the domain name.

√ - The load balancer is setup properly; in that I can load my landing page in the browser (from the EC2 instance) providing the long DNS name url of the load balancer.

√ - I can setup any number of subdomains in Route53 for this domain instantly and without problem for an s3 bucket or EC2 instance.

Therefor there doesn't seem to be a problem specifically with either my domain or the load balancer on their own.

The setup for my record set it as follows is as follows (following a couple of the AWS docs)

name: subdomain [.mydomain.com] Alias: Yes Alias target:

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( no code to share )

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Expected: The same outcome of typing in the full load balancer dns name in the address bar.

Actual: Browser message

This site can’t be reached

subdomain.mydomain.com’s DNS address could not be found. Diagnosing the problem.
DNS_PROBE_STARTED

and then

subdomain.mydomain.com’s server IP address could not be found.
DNS_PROBE_FINISHED_NXDOMAIN

☺ Thanks ☺

Answer 1

Make sure you're using the A record type, not a CNAME. https://aws.amazon.com/premiumsupport/knowledge-center/route-53-create-alias-records/

A records typically only point to ipv4 addresses, and this is still technically the case here:

Route 53 alias records are mapped internally to the DNS name of alias targets such as AWS resources. Route 53 monitors the IP address associated with an alias target's DNS name for scaling actions and software updates. The authoritative response from Route 53 name servers contains an A record (for IPv4 addresses) or AAAA record (for IPv6 addresses) with the IP address of the alias target.