Yun Shield fails to keep connection with UDP server with listener socket


I have followed this link for recovering the yun shield with firmware upgrade.

But the device does not stay at FailSafe mode. It disconnects the UDP connection.

The device will create the UDP server at
My laptop connected with cross over RJ45 Yun shield laptop has ethernet IP

What could be the reason for this disconnection? I did the factory reset once. So, Is there any way that I can communicate with this shield?