Company has more than 1000 machines, workplace have recently emerged several machines can't obtain IP address, in switches and computer network cable, the port has back card points, reinstall system, even in the host, in exchange for a switch interface includes a network segment, could not obtain the IP, to find the network room as well as domain administrator said there is no problem, they see the PC on the switches have been get to, but the computer can't gateway, DNS, sometimes in the center of computer network in detail, showing has access to the IP address, DNS and gateway or not, the following shows an exclamation point, did not identify the network and other machine have no problem with network segment, who know what's the problem? Pray god help!!!!!!!!!!!