title: Flask app is giving 404 to routes from public ip
body: <p>I am running a Flask app.</p>
  
  <pre><code>    app = Flask(__name__)
      app.run(host="0.0.0.0", port="5000")
  
      @app.route('/list', methods=['GET'])
      def get_all_list():
        star = mongo.db.listdata
  
      if __name__ == '__main__':
          app.run(debug=True)
  </code></pre>
  
  <p>My public IP :- 100.x.x.x</p>
  
  <p>When I am accessing <code>100.x.x.x:500/list</code> it is giving me 404 not found.
  Server is running, as I can see the request in the flask console. But it is giving 404 to all routes. </p>