Poweredge C6100 AMD motherboards : IP recognition issues

Hi Dell,

I have Poweredge C6100 server with three AMD chipset motherboards. Here's the configuration:

motherboards: Tyan S8208

cpu: six-core AMD opteron(tm) processor 2419 EE

All three nodes send out ping well, but they have trouble recognizing both public and private IP, so cannot open web page.

Accurately saying, out of 3 nodes, 2 nodes don't recognize both public and private IP and one node recognizes only public IP but not private.

I contacted the seller and he said there might be a switch that needs to be toggled in the BIOS, but I can't find where the switch is.

Please help!