title: How to get Heroku app's IP address
body: <p>I am running a Heroku app. I am supposed to answer the question "what is your server IP address" by some customer. I am used to figuring out the IP addresses through pinging my domains.</p>
  
  <p>With Heroku, I have two issues here:</p>
  
  <ol>
  <li><p>When I ping my custom domain the IP address I get is different from
  when I ping the original app domain.</p></li>
  <li><p>The ping does not go through.</p></li>
  </ol>
  
  <p>Examples:</p>
  
  <pre><code>myhost:~ 1111$ ping fstrk.herokuapp.com
  PING us-east-1-a.route.herokuapp.com (23.23.207.27): 56 data bytes
  Request timeout for icmp_seq 0
  Request timeout for icmp_seq 1
  Request timeout for icmp_seq 2
  ^C
  --- us-east-1-a.route.herokuapp.com ping statistics ---
  4 packets transmitted, 0 packets received, 100.0% packet loss
  
  
  myhost:~ 1111$ ping dashboard.fstrk.io
  PING dashboard.fstrk.io.herokudns.com (54.243.243.251): 56 data bytes
  Request timeout for icmp_seq 0
  Request timeout for icmp_seq 1
  Request timeout for icmp_seq 2
  Request timeout for icmp_seq 3
  ^C
  --- dashboard.fstrk.io.herokudns.com ping statistics ---
  5 packets transmitted, 0 packets received, 100.0% packet loss
  </code></pre>
  
  <p>I have poor knowledge of networking so I am probably doing this wrong. What is the correct way to obtain the current IP address, and why are they different although they point at the same app?</p>