Ethernet port in Thunderbolt Display connecting intermittently

Well this is a bizarre thing. My Thunderbolt display shows a green bubble against "Bluetooth PAN" when a cable is plugged in, configures through DHCP with a plausible address, though it will not transfer data across the connection.

The ethernet connection is fine. Plugged directly into the MacBook Pro that drives the display it works just as it should.

My ethernet connection through the Thunderbolt display was a little finicky at first. Then it was fine for a couple of months. Now, suddenly, I can get no ethernet connection through the display. If I plug the ethernet cable directly into my MBP it works like a charm, but nothing I do can get the Thunderbolt display to work with ethernet. I've had this issue now for a couple of days and have been trying every combination of cables and settings with no success.

Restart is the only solution that's been working for me.

Restart doesn't help me, I'm afraid. I also tried unplugging/replugging the power to the actual display, hoping that might do some kind of reboot. No luck. My ethernet connection of the thunderbolt is 100% dead. 😟

Happ to report I found the answer here: https://discussions.apple.com/thread/3447535?answerId=16585359022#16585359022

It seems to have worked.

🙂

@Endurion:

Unfortunately, this (using ifconfig to restart the device) doesn't work in my case. My only solution so far has been a reboot.

Also, note that there is no reason for 'en4' being usually the Ethernet Display, and en0 is not always the WiFi. In my case, en0 is the ethernet display and en1 is the wifi. My understanding is that it is following the order of the devices in your device list.

@Swiink

The link you posted is NOT about the problem discussed here. Please read the thread before posting! 🙂

I've resolved the issue getting my MacBook Pro 13" to reconnect to the Thunderbolt display so it functions properly as a docking station. Again I have an Apple USB keyboard and Ethernet cable plugged into the back of the TBD. Was having trouble getting these to operate when reconnecting the MBP. Here's the method I found works:

1.) Start with MBP in sleep mode and closed clamshell.

2.) Connect power supply and plug in Thurnderbolt Display connector.

3.) Open clamshell and wake up MacBook.

4.) Wait until display comes up on Thunderbolt monitor.

5.) Close clamshell.

By using these steps both my Ethernet connection and keyobard both operate properly.

On my side, the last Mac OS X update (10.7.3) seems to have entirely solved the problem.

Weel, it happened again this morning when I connected my MBAir to the display, I updated my computer to 10.7.3. Can anyone reproduce the problem?

- ethernet cable is connected to screen

- connect the MBAir to the thunderbolt

- press usb keyboard to wake up computer

- switch off wifi

At that point, I lose internect connection as the ethernet stays inactive. Rebooting the computer solves it.

Try hooking up you MBAir this way....connect power supply and Thunrderbolt display cable. Wake up Macbook Air by opening up cover and hitting space bar on laptop (not the external keyboard). After Macbook Air wakes up wait until display comes up on Thunderbolt. Then close laptop cover. You should end up with Ethernet connection and keyboard operating without having to reboot. This method has been working for me.

Forget my last message. The problem is back.

I'd rather say the problem never went away.

Same issue here with a thunderbolt enabled 15" MBP running 10.7.3 and all updates. I deleted the Display ethernet and tried to add it back, but it is is not shown in the drop-down. The ethernet is clearly not being identified by the MBP.

Thunderbolt works fine to a Promise R6, and a second display chained.

USB works, but I do have the mystery lost key strokes if I use a USB keyboard (or clicks when using a mouse). Bluetooth keyboard/mouse work fine.

The display firmware clearly still has MAJOR issues.

Following up to my own post.

I rebooted the MBP, and the display ethernet was available again.