title: Elastic Load balancer listener not working for one port
body: <p>I have an Elastic Beanstalk Docker container running a Sinatra app. Using ebextensions, I have an haproxy instance running on the EC2 box - that forwards traffic from port <code>9090</code> to the <code>docker_ip:application_port</code>. The setup works fine, since I am able to curl the EC2 box's IP on port <code>9090</code> and hit my application's endpoints (I am also able to see the haproxy logs)</p>
  
  <p>Now, I have set up an additional tcp listener on Elastic loadbalancer to forward port 9090 to port 9090 (the default is port 80 -> port 80). However when I try to access <code>domain_name:9090</code> , it times out. If I just access <code>domain_name</code> it works. Any ideas on how I can go about debugging why the load balancer listeners are not working as expected.</p>
  
  <p>Note, the ELB visibility is set to public.</p>
  
  <hr>
  
  <p>So, I turned on logging for the load balancer and accessed it's DNS name directly. It logged the requests sent to port 80, but not the ones sent to port 9090.</p>
  
  <hr>
  
  <p>Another update - I ran a tcpdump on the ec2 box on port 9090. It did not capture any packets where I ran <code>load_balancer_domain:9090</code></p>
  
  <hr>
  
  <p><strong>Solved</strong> - I had to edit the security group rules on the load balancer to allow outbound traffic on port 9090 for the instance.</p>