Ethernet (LAN) not working after Yosemite upgrade..

Same problem here.

iMac 27" Late 2013.

WiFi works.

Ethernet worked but after reboot it does not work anymore.

The problem is NOT my router. All other devices (computers, NAS) connected to it via Ethernet work.

Ethernet in "Network" System Preferences Panel says "Self-assigned IP address". No internet connection (via Ethernet).

Apple, please fix this !!

Same here.

MacBook Pro (15-inch, Mid 2010)

Any machine on my network that hasn't been upgraded to Yosemite is fine. Any on Yosemite seem to be throttled to 1-2mb upload speeds (expect 30).

hmchun90: Perfect! Fixed my ethernet adapter problem.

Try this:

• system preference
• network
• make sure using "Location: Automatic"
• Assist me...
• Diagnostics...
• choose Automatic then Continue
• Choose the network port you using Ethernet or Wi-Fi then Continue
• restart your router/modem and select Continue

Hope this help 🙂

check your internet connection.

Turn off wifi connection then tried again my step

just wondering if you found a solution. I have the same problem.I actually have two macbook pros using Yosemite 10.10.1 that both have the same problem. Did your renaming the system configuration folder work? I just posted a question for discussion yesterday.

Same issue here. I did notice that it happens overnight, and that if I restart my box and plug the ethernet cable into the other ethernet port on the back of my Mac Pro (mid 2010), it works. That is, until another night goes by then it stops working.

Wifi works fine though.

Please fix, Apple!

This worked for me:

1. Hooked a different computer to the network

2. Got network info from that computer in Network settings

3. Manually entered the IP, subnet mask, router and DNS server from other computer (I did have to try different IP addresses until I found one that worked).