Ubuntu Install on Sun Fire X4100 network issues

Hi

I have two Sun Fire X4100 machines with Ubuntu 12.04 installed on them.
I am able to configure the Net Mgt port with an IP address and access the ILOM from the browser. I can also boot the Ubuntu installed and redirect the output.

The issue i have is that when i configure the network interface(NET0) from Ubuntu and connect an ethernet cable to it i am unable to reach it via ping or ssh. I am also unable to ping out from it. I can confirm that all the network parameters(IP address,Netmask,gateway) are set correctly. And the NET0 interface is connected to the same switch the Net Mgt is connected to. I can ssh and ping the Net Mgt but not the NET0 interface.

I will really appreciate your help. Thanks