title: Why do my ELBs have two IP addresses? How to find them?
body: <p>I have both application and classic internal load balancers running over a <em>VPC</em>.
  Each of them are associated to three subnets, on different availability zones, and almost each of them point to only one instance (in my case <em>ECS</em> containers).</p>
  
  <p>But when issuing a <strong>nslookup</strong> command (<code>nslookup internal-MYLB.us-east-1.elb.amazonaws.com</code>)</p>
  
  <p>I can see that output:</p>
  
  <pre><code>Server:     10.xxx.xxx.37
  Address:    10.xxx.xxx.37#53
  
  Non-authoritative answer:
  Name:   internal-MYLB.us-east-1.elb.amazonaws.com
  Address: 10.xxx.xxx.187
  Name:   internal-MYLB.us-east-1.elb.amazonaws.com
  Address: 10.xxx.xxx.204
  </code></pre>
  
  <p>For each load balancer, wether it's a classic or application one, two IP addresses are associated to its domain name.</p>
  
  <p>I was simply wondering:</p>
  
  <ol>
  <li>Does it correspond to two load balancer nodes for each load balancer? (Maybe I missed it but I didn't find that info in their doc)</li>
  <li>Does <em>AWS</em> systematically spawns that for redundancy? Is it configurable? </li>
  <li>Is there some way in the UI to see those IP addresses (I didn't find them in the UI or by using <code>aws elb describe-load-balancers</code>)</li>
  </ol>
  
  <p>For the context, we have a remote partner who experiment issues with only one of the two IP addresses associated to a load balancer, maybe something like a network conflict due to some overlapping subnet range, but I'd prefer to be sure of what I see first.</p>