title: Error 503 on Varnish on Setup
body: <p>I have set up Varnish on my centos server which runs my drupal site.
  Browsing to any page returns a blank page due to 503 :Service Unavailable</p>
  
  <p>I have read many questions and answers about intermittent 503's but this is occurring constantly. I can still browse to the site using www.example.com:8080 .</p>
  
  <p>I am running on Centos 6 using the VCL : 
  <a href="https://raw.githubusercontent.com/NITEMAN/Varnish_VCL_samps-hacks/master/varnish3/drupal-base.vcl" rel="nofollow">https://raw.githubusercontent.com/NITEMAN/Varnish_VCL_samps-hacks/master/varnish3/drupal-base.vcl</a></p>
  
  <p>I have also tried <a href="https://fourkitchens.atlassian.net/wiki/display/TECH/Configure+Varnish+3+for+Drupal+7" rel="nofollow">https://fourkitchens.atlassian.net/wiki/display/TECH/Configure+Varnish+3+for+Drupal+7</a> .</p>
  
  <p>Not sure where to even start in debugging this.</p>
  
  <p>ADDITIONAL INFO:
  NITEMANS answer below provides some really helpful debug suggestions.
  In my case it was something very simple, I had left the default 127.0.0.1 in my default.vcl . Changing this to my real external IP got things working. I hope that is the correct thing to do!</p>