Domain not resolving EC2 Instance

Hi Steve, thanks for the quick reply.

I've opened up the security group associated but how do I check its open?

I also could not get the http:// to work? the Elastic IP works directly for me though

$ nslookup app.blockchatdao.com
Server:  dns.google
Address:  8.8.8.8

Non-authoritative answer:
Name:    app.blockchatdao.com
Address:  3.210.166.43

Both http://app.blockchatdao.com/ and http://3.210.166.43/ work for me. But I get connection timeout on both https://app.blockchatdao.com/ and https://3.210.166.43/

You can check that port 443 is open in the security group in AWS Console -> EC2 -> Instances and then select the instance, go to the security tab and verify the inbound rules.

On the instance itself, is the webserver setup to listen on port 443?

Is there a host-based firewall, and is this allowing port 443 traffic through? Depending on what OS the instance is running this could be firewalld (RHEL/CentOS/Fedora), or ufw (Ubuntu), or Windows Firewall, or something else (or you might not have a host-based firewall running at all).

Best place to start is double-checking the security group has the port open, and that the webserver is listening on that port.

Those security group rules look fine.

Are you now able to view the website using HTTP to both the DNS name and the IP address?

Port 22 being open in the security group suggests the EC2 is running Linux, is that correct? Check what ports are opened and being listened on with netstat -tulpn

If the output is too large, limit it to just the webserver ports netstat -tulpn | egrep -w '80|443'