A guy I work with gave me the EC2 credentials to log onto his EC2 console. I was not the one who set it up. Some of the instances show a public dns name and others have a bl
It is related to the VPC's feature called "DNS Hostnames". You can enable or disable it. Go to the VPC, under the Actions menu select the "Edit DNS Hostnames" item and then choose "Yes". After doing so, the public DNS of the EC2 instances should be displayed.