title: Accessing SQL Server Instance through NAT
body: <p>I'm attempting to access a SQL Server which is exposed through an IP NAT mapping.  All the ports are open.  I don't know the details of the NAT, if it's relevant, since that's somewhere else in the company hidden in a pile of red tape.</p>
  
  <p>Here's what I figured out.  When you attempt to access a named instance of SQL Server, the client asks what port the named instance is running on.  If I RDP into the SQL Server I can use <code>netstat</code> to find out the port of that instance and can successfully connect through the firewall.  However, connecting via the instance name doesn't work.  My guess is that the server is responding at some point with it's internal IP address and the client is using that.</p>
  
  <p>Does anyone know if this is true and if there's a way around it?</p>