title: Is it possible to make a Load balancer (ELB) only be accessed by SNS?
body: <p>I'm creating an internal application load balancer in AWS. I want it to be available/reachable only by SNS and blocking every other request.</p>
  
  <p>I tried looking for the SNS IP's used by AWS (so I can whitelist only those) but there isn't a reliable range.</p>
  
  <p>Is there any way to do this?</p>
  
  <p>PS.
  I'm using cloudformation</p>