title: How to point Dns and manage Nginx redirection properly
body: <p>I am facing the following situation: 
  I own a domain name, let's say example.com at name.com
  We have a website hosted at bluehost on a shared hosting with an IP1
  We have an ERP (odoo) hosted at digitalocean on a droplet where Nginx is running and where IP2 is allocated.
  The erp is accesible via IP2:port_number
  I am trying to redirect erp.example.com in direction of odoo while keeping the main domaine <a href="http://example.com" rel="nofollow noreferrer">http://example.com</a> to point to IP1</p>
  
  <p>I have tried to setup two A record. One for erp.example.com to point to IP2 but here I can not specify the port at name.com, problem is it doesn't seems even to point on the 80 port as I don't see the Nginx welcome page when I type <a href="http://erp.example.com" rel="nofollow noreferrer">http://erp.example.com</a></p>
  
  <p>I have setup another A record which point to the bluehost IP1 on a wordpress website and this works fine.</p>
  
  <p>DNS are recorded with two ns of bluehost only.</p>
  
  <p>Based on my understanding I should point the erp.example.com to IP2, then set nginx to filter erp.example.com to go to IP2:port with a redirection ?</p>
  
  <p>I don't understand why my A record pointing to IP2 doesn't direct me to the digital ocean server. In Chrome it gives me a ERR_NAME_NOT_RESOLVED .</p>
  
  <p>What am I doing wrong ?</p>