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

Hi,

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

http://wiki.dragino.com/index.php?title=Yun_Shield#How_to_recover_the_Yun_Shield_in_case_of_a_firmware_crash

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

The device will create the UDP server at 192.168.255.1/255.255.255.0
My laptop connected with cross over RJ45 Yun shield laptop has ethernet IP 192.168.255.2/ 255.255.255.0

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?

Best,
Tajuddin