I'm running a Mac Pro (Early 09) on 10.10.5 and I have a semi-persistent internet connectivity issue. After scheduled resetting (overnight), the computer will return with no internet connection even though it is a wired connection and no changes have been made to the hardware, software, or how it connects in that time. At first the issue seemed related to this MacRumors Topic as I was receiving a similar self-assigned IP address as the OP but I was receiving it over a wired connection to the router: http://forums.macrumors.com/threads/macbook-self-assigning-ip-address-cant-connect-to-wifi.1724892/ (In fact, as soon as the Wired Connection is allowed to use DHCP [changed from OFF], it interrupts all connections, including the previously working Wifi connection, until the wired connection is turned off again) I've had to switch to a Wifi connection to make this post as my ethernet connection, on the same device, is continuing with this issue despite now receiving an proper IP address. But even after receiving a corrected IP, the internet itself did not seem to be getting to any of my cloud apps in the top bar and was not allowing internet browsing. So it seemed to register as connected but allowed no activity that a connected computer would. In the diagnostic, the ISP is lit red as Failed, however, I am fully connected on Wifi so an ISP problem seems unlikely. So what is causing this ethernet problem that doesn't register as a problem to the computer itself?