Built-in Ethernet not available

If you connect it to another Mac via Ethernet does it show up then?

I think I am having a similar issue, but wanted to confirm that it is the same thing that is happening to you. Does the ethernet work for 10-30 min after initially booting up the computer and then stop working?

I am thinking that the problem is a physical one perhaps due to overheating, but the apple support topics have been down the last two days so I have not been able to look into the problem there.

Mac Book Pro Mac OS X (10.4.7)

I'm having a similar issue, but only since updating to 10.4.8.

I switch internet connections daily, going from home to work. At work, I use the built-in ethernet. Prior to 10.4.8 I just had to switch location to the one I use at work, and keep on working. Since the "upgrade" it fails to recognize the ethernet connection unless I do a restart.

This is more likely a software issue than something like overheating.

So, UlfStein, does restarting solve the problem for you, or do we have different issues?

I have a similar problem with my brand new MacBook Pro. I'm connected to the Internet via an Ethernet cable connected to my router.

It seems that when I download any large files, such as an update through Software Update, streaming video in Safari, or having a voice chat with someone, the Internet appears to die completely.

It's not my router's problem, as there are two PCs running off the router and their Internet connection remains fine while my Mac is offline. When this happens, Safari eventually times out when opening new pages and eventually says that I am not connected to the Internet. It also takes quite a few seconds for the Built-In Ethernet Network Status to report that I'm no longer connected.

To get the Internet working again, I find that putting my MacBook Pro into Sleep mode and then waking it up does the trick everytime, but it's just annoying to have to do that. This has been happening in both Mac OS X 10.4.5 and 10.4.8.

Any suggestions to resolve this problem would be greatly appreciated!

Hey,

to add to the pool: I got the same problem. MacBook Pro, 1.83GHz. Airport at home, Ethernet cable at work. It won't recognize the Ethernet port, and I do have to restart the system to solve the problem, then it will work fine. Yes, I agree, it's a software issue. No, I did not find another solution except the reboot yet.

I.

another one bites the dust... I, suddenly, got the same problem. It worked fine a few days ago.

OK, how stupid of me...

my problem was solved by simply going to System Preferences --> Network --> Selecting Built-In Ethernet from the "Show" popup menu under "Locations", then selecting the "Ethernet" tab and selecting "Automatically" from the Configure popup menu.
Somehow it was in manual, don't know why. Everything is back to normal.

Same problem here. New C2D 15 inch MacBook Pro. Wired ethernet connection dies from time to time and putting the laptop to sleep helps immediately. Refreshing DHCP doesn't help. Entering IP data manually neither...

Once again I spoke too soon...

After a day or two of normal function Ethernet is dead... again!

At some point I managed to make it appear in the list of available ports, but although the cable was connected, its status was red (No ethernet cable recognized)

Running the ifconfig command in the terminal gave me the following results, concerning the ethernet:

----
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
ether 00:0a:95:d1:29:ec
media: 100baseTX <half-duplex> (none) status: inactive
supported media: none autoselect 10baseT/UTP <half-duplex> 10baseT/UTP <full-duplex> 10baseT/UTP <full-duplex,hw-loopback> 100baseTX <half-duplex> 100baseTX <full-duplex> 100baseTX <full-duplex,hw-loopback> 1000baseT <full-duplex> 1000baseT <full-duplex,hw-loopback> 1000baseT <full-duplex,flow-control> 1000baseT <full-duplex,flow-control,hw-loopback>
----

Hello all, I don't know if it's any good to add to this, but mine too... brand new macbook pro, suddenly won't recognize ethernet cable but used to! I did the troubleshooting mentioned here and also the hardware test said nothing was wrong. very frustrated.

MacBook Pro Mac OS X (10.4.8)

MacBook Pro Mac OS X (10.4.8)

I had to permanently disconnect the ethernet from my PB. I noticed that when it was connected to the LAN via the HUB, none of the other machines could use the network.
I also noticed that the led on the hub corresponding to my PB was blinking rapidly and another red led named "COL" was lit. That stands for a "group collision", whatever that means.

Anyway, right now I am just using the airport.

Message was edited by: Manos Krokos

Set it back to Auto and not manual. From the ifconfig you output, you have manually selected a lower speed half duplex link. Using a hub instead of a switch the port should auto-negotiate to the correct link speed anyway.

In laymans terms the collision light means that the data packets are not getting to their destination intact - what this causes is a resend of the data (hence th rapid blinking if you're getting a lot of collisions).

Have you tried swapping around some of the ports? Could you have a hub that has a hardware fault and some dead ports?

I tried different ports on the hub. Even the ones that other machines operated perfect upon, don't respond to me PB correctly. I get the same problem.
The only thing that works (temporarily, until another restart) is to manually set the ethernet to 10baseT/UTP, full duplex. As soon as I select automatic setup, ethernet fails.

So if you set it to 10BaseT it'll work. Then after a restart it will no longer work even though it's still set to 10BaseT. Is that correct? Do you have access to a switch you could test your machine on to confirm whether or not the hub is the problem.

Test powering off the hub when everythign is connected and then powering it back on to see if that forces everythig to work too. I'm tempted to blame the hub myself, but without fully testing it, you could still have PB issues i guess.