title: The ec2 instance can't access internet in a public subnet without a elastic ip address?
body: <p>I working on aws. I created a public subnet which has a network ACL allows all net traffic, and associated with a internet gateway in the route table.</p>
  
  <p>And then I create a ec2 instance without elastic ip and a ec2 instance with elastic ip in it, and the security group also allows all traffic.</p>
  
  <p>I ssh to the instance which has elastic ip. It works well when I run yum update and curl www.baidu.com and so on. But I can't access internet when I ssh to the ec2 instance which has no elastic ip. anyone knows that is why?</p>