9. Route 53

Question 1

You have purchased mycoolcompany.com on Amazon Route 53 Registrar and would like the domain to point to your Elastic Load Balancer my-elb-1234567890.us-west-2.elb.amazonaws.com. Which Route 53 Record type must you use here?

Answer 1

ALIAS

You can’t create a CNAME record that has the same name as the top node of the DNS namespace (Zone Apex), in our case mycoolcompany.com.

Question 2

You have updated a Route 53 Record’s myapp.mydomain.com value to point to a new Elastic Load Balancer, but it looks like users are still redirected to the old ELB. What is a possible cause for this behavior?

Answer 2

TTL

Each DNS record has a TTL (Time To Live) which orders clients for how long to cache these values and not overload the DNS Resolver with DNS requests. The TTL value should be set to strike a balance between how long the value should be cached vs. how many requests should go to the DNS Resolver.

Question 3

You have purchased a domain on GoDaddy and would like to use Route 53 as the DNS Service Provider. What should you do to make this work?

Answer 3

Create a Public Hosted Zone and update the 3rd party registrar NS records

Question 4

What is the CNAME record type used for?

Answer 4

Hostname to hostname

• only for NON-ROOT domain

Question 5

What is the ALIAS record type used for?

Answer 5

Hostname to AWS Resource

• works for ROOT and NON-ROOT domains