DNS - Trying to map subdomain to site on EC2

Question

I have a problem where I can't browse a website hosted on an Amazon EC2 IIS instance by domain name. I can browse it by the public elastic IP address I assigned to the instance.

I created a DNS A record pointing a sub domain to the public Elastic IP address. www.whatsmydns.net shows that it is propagated. However, I can't ping my subdomain (ping cannot find the host).

In IIS I created a binding for my subdomain pointing to the private IP address for the elastic IP.

I don't think it matters, but I also created a binding for an empty host name and * for the IP address to be able to connect by the public IP.

I'm completely new to EC2 and thought I wasn't doing something correctly with the elastic IP and/or IIS binding but it's troubling that I can't ping the subdomain. Or, maybe that is expected since I can't browse the site either.

Where have I gone wrong? What should I try/check next?

Answer 1

You can't ping the EC2 instance because by default the security group assigned to your EC2 instance will be blocking ping. To unblock it, modify your security group and add a Custom ICMP Rule to allow Echo Request and Echo Reply.

As for getting your DNS to work within IIS, if I were you to start with, I'd remove all bindings from IIS and then see if you get anything when using your subdomain.

Double check that your subdomain definitely resolves to your elastic IP, you can do this through a command prompt, e.g. nslookup subdomain.domain.com