 <p>That's an error Windows gives when you're trying to bind to an address on the local machine that's not assigned to any of the adapters on the machine. If <code>ipconfig</code> doesn't show it, you can't bind to it. </p> <p>If the external address is on a router that is NAT'ing requests from it to the server's internal address, you can't bind to it because it's on a different machine. This is probably the case. You might want to bind to <code>socket.INADDR_ANY</code> (or its Django equivalent). This will bind to all addresses that are on the machine right now.</p> <p>Also note that if the external address is NAT'ed to your internal one, binding to the internal one should be enough.</p>