interface enp025 disappear when my laptop is disconnect

Hi Everybody

I have a pc laptop thinkpad lenovo with opensuse gnome 13.1 onboard (64 bit machine).
When I get disconnected from the network for a while, disappear the wired interface enp0s25 and i have to restart my laptop to re-connect to the wired network.
This wired interface (I mean the enp0s25) is configured with “auto” startmode , maybe I have to set it to ifplugd mode?
Furthermore, there is a timeout that bring this interface down and consequently it forces the pc to restart?
Thanks for all your advices.
MAX

Are you using ifup or NetworkManager?

I’m using NetworkManager.
MAX

As far as I can tell, it is normal. NetworkManager deactivates interface on link down event and should activate it again on link up.