Some devices are getting the APIPA addresses, when they connect. They can't get on the network. Our Sonicwall NSA2400 is the DHCP server. Even when I provide a static IP address, the ailing device would still not connect to the LAN. My laptop was connected to the LAN, hardwired, this morning. Now however, it's not connecting. My wireless is connecting though. I've seen this LAN disconnection, from 2 other devices today. Restarted my domain controller and an additional DNS server. A third DNS server cannot be restarted right now, because it is a file server that is used a lot, during work hours.