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I have a domain example.com. I want to point this domain to my AWS internet-facing classic ELB public DNS (my-elb-123456789.us-west-2.elb.amazonaws.com) without using Amazon Route 53. How should i configure elb DNS in my domain (example.com) DNS records as a CNAME? Then what is my 'A' record in DNS configuration?

skg
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You can use any DNS provider to direct subdomain traffic to an AWS load balancer. Create a CNAME record that has the value set to the ELB CNAME. This has to be a subdomain with most DNS providers - the www subdomain would be most common. AWS Documentation.

Setting the domain apex to point at the ELB is more difficult. You can't use an A record as the IP of the ELB changes, and you can't put a CNAME at the domain apex as it's against the DNS specification.

Some providers let you create something similar to a CNAME at the domain apex, including Route53 and CloudFlare, in a way that meets the DNS specification.

If your provider won't let you set a CNAME at the domain apex you'll have to create an A record and some kind of redirection. Some options include:

  • A t2.nano EC2 instance with Nginx returning a 301 redirect
  • CloudFlare and a page rule (though if you're using CloudFlare it's better to use the solution above)
  • S3 bucket redirection (only works on http, not https)
Tim
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    If your DNS provider *does* let you put a CNAME at the Apex of a zone, then you have a DNS provider that doesn't understand how DNS works. This is an invalid configuration, always and everywhere. Cloudflare doesn't create a real CNAME record. Their "CNAME flattening" feature actually creates an A record and does a back-end lookup, similar in behavior to a Route 53 alias. Some providers call this an "ANAME" which is not a real RR type, but is similar to what Cloudflare is doing. – Michael - sqlbot Aug 22 '17 at 01:50
  • There are multiple instances where using a CNAME for ELB will not work. Some service require an A record and not a CNAME. The advantage of Route 53 is that it allows "alias" records that appear to be A records, but in the backend point to another AWS service. This is the case for both ADFS SSO, and E-mail servers (to avoid spam filtering). – Appleoddity Aug 22 '17 at 02:17