I HAVE MY DELL POWER EDGE 6800 WHICH I USSUAL USE IT AS A SERVER BUT FOR THE TWO DAYS NOW I AM AN ABLE TO ACCESS IT REMOTELY AND EVEN WHEN AM THERE PHYSICAL IT CONNECTED TO A NETWORK BUT IT NOT SENDING OR RECEIVING PACKETS, I TRIED TO CHANGE NETWORK-CARD BUT STILL ITS NOT WORKING. WHAT COULD BE...