I have created an instance on Amazon EC2 then installed whm and cpnel. I am able to access cpanel just by using my domain name ex. domainname.com/2083 but when i go to my domain mane ex. domainname.com it gives This site can’t be reached...
I am a bit confused if site wasn't pointed properly then it should not go to Cpanel either but since its able to access cpanel then why its not displaying the website.
I have already rechecked name servers and host name.
You should login to your AWS EC console then go to the Security Groups and create a custom allow rule for the HTTP traffic (port 80) and also HTTPS traffic (port 443), both on TCP. By default, amazon only allows you ssh access to your amazon instance. If those ports are not listed on the Security Groups, then none of your sites will be accesibile to the public. Since you are able to access cPanel on port 2083 I suppose you already have a tcp rule to permit access on port 2083.
I got the issue with Windows EC2 while connecting through HTTP 80 port and followed below link.
If your computer is on a corporate network, ask your network administrator whether the internal firewall allows inbound and outbound traffic from your computer on port 22 (for Linux instances) or port 3389 (for Windows instances).
If you have a firewall on your computer, verify that it allows inbound and outbound traffic from your computer on port 22 (for Linux instances) or port 3389 (for Windows instances).
or follow link: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/TroubleshootingInstancesConnecting.html#TroubleshootingInstancesConnectionTimeout
Check Firewall settings in your Windows EC2: Goto > Firewall Settings or Properties choose public profile > check inbound connections, change to "Allow" if it is "Blocked by default"
来源：https://stackoverflow.com/questions/40620719/this-site-can-t-be-reached-amazon-ec2