No Internet : oneprovider Server

[Lenuxfrance]

Hello , I have a dedicated server at onepovider with Promox 6 with 1 single ip
I installed Windows: Ok
However, I can't get Internet on it.
I entered Windows :
Main IP: 51.*********
Failover IP:
Network mask: 255.255.255.255
Gateway: 51.********

And the Mac address under promox

What's wrong with my setup?

Thanks for your help