Sub domain connect to AWS EC2 Instance

Hi, you can manage the subdomain name by another DNS provider to have the one that you exactly want as long as you do proper remapping via CNAMES

See https://support.dnsimple.com/articles/differences-between-a-cname-alias-url/ and https://ie.godaddy.com/help/edit-a-cname-record-19237 (for Godaddy but similar for other DNS providers)

You will just have to remap the public dns name (under amazon domain) of your ec2 instance to your cname of choice.

on your 3 points:

• remapping the amazon domain name of your instance to your own subdomain is free
• this will have no impact on workload and site working speed. The initial name lookup with your subdomain may be a few ms longer because it will go your subdomain alias -> amazon name -> amazon ip instead of just the last 2 but it will happen only once and in usually unperceptible from user standpoint
• the security of your instance is unchanged: you will do same security definitions on it independently of dns remapping or not