I have a thunderbolt to ethernet cable on a MacBookPro Retina on Lion.
Sometimes the thunderbolt to ethernet connection does not work. It seems to occur when I switch network locations (e.g., I move from my home network to my work network). Restarting the computer fixes the problem, however, I don't want to have to restart my computer.
How can I force thunderbolt to ethernet to connect without restarting the computer?
More details:
Under network settings, there is a red dot and not connected on "Thund…thernet".
It further says:
Status: Cable Unplugged
Either the cable for Thunderbolt Ethernet is
not plugged in or the device at the other end
is not responding.
Under system information – thunderbolt it states
Thunderbolt to Gigabit Ethernet Adapter:
Vendor Name: Apple, Inc.
Device Name: Thunderbolt to Gigabit Ethernet Adapter
Vendor ID: 0x1
Device ID: 0x8003
Device Revision: 0x1
Route String: 3
Firmware Version: 5.5
Port:
Status: Connected
Link Status: 2
Port Micro Firmware Version: 0.0.8
Under Network – Thunderbolt Ethernet it states:
Thunderbolt Ethernet:
Type: Ethernet
Hardware: Ethernet
BSD Device Name: en1
IPv4:
Configuration Method: DHCP
IPv6:
Configuration Method: Automatic
Proxies:
Exceptions List: *.local, 169.254/16
FTP Passive Mode: Yes
Service Order: 0
Best Answer
I had this problem, too, and an Apple Support call and Genius Bar visit later, I had the answer: if you're using Network Locations that preexist your Thunderbolt display, it doesn't seem to auto-add the possibility of "Display Ethernet" to your available network ports. To solve this, either:
Create a new Location in your Network system preferences. It will finally detect the "Display Ethernet" and use it. It'll slowly change from disconnected to No IP to green-is-for-go.
or
Fix an existing Location by clicking the + to add a port and choosing Display Ethernet. It'll slowly change from disconnected to No IP to green-is-for-go.