Ethernet Port "Broken" and/or Low Speed

[Macterial Girl]

This may have been discussed here but I cannot find anything on it. When I upgraded to El Capitan, I suddenly lost the ability to connect via my Ethernet port. I searched the web and found several fixes but now I notice that I can only connect at 10baseT/UTP and my internet speed is horrible. The speed test I just ran was 9.46/9.45Mg. I pay for Comcast Blast which is 75 down. I switched out my Ethernet cable to a Vandesail Cat7, but not any better. I connected the cord to my Windows laptop and was getting 300+down and 90+ up - no kidding. I connect directly to the Comcast modem/router and should be getting at the very least what I pay for. Other computers in this house do, just not my Mac. So, whats up and how can I fix this?
TIA!

 

[Randy B. Singer]

Do this to reset your Ethernet:

In the Finder, choose: Finder menu —> Preferences
Click on the General tab at the top.
Under Show These Items On The Desktop, make sure that Hard Disks is checked.

Now go to:
Macintosh HD —> Library —> Preferences —> SystemConfiguration

Drag the SystemConfiguration folder to desktop. DO NOT trash it.

Restart your computer.

See if your Ethernet works properly now. If it does, you can trash the SystemConfiguration folder on your desktop. If it doesn’t, and there are any problems, you can always put the SystemConfiguration folder on your desktop back where it was (after first trashing the new fresh copy that was automatically generated when you restarted).

 

[Macterial Girl]

Thank you for your reply, unfortunately that didn't work. After doing your suggestion, I went back to the hardware settings under Network and tried to have it configure automatically and now I'm back to Wi-Fi because it continues to say "cable unplugged". It won't even go back to 10baseT/UTP now. So frustrating!

 

[harryb2448]

Try a different cable. Most of us have several at least laying about.

 

[Macterial Girl]

I've tried three, all three work perfectly on other machines.

 

[harryb2448]

The age of your whatever Mac may have some effect as a machine as early as a 2007 MBP will handle El Capitan. Have a read of this link from 2008 on slow connection speeds:-


http://www.mac-forums.com/internet-networking-and-wireless/113065-gigabit-ethernet-slow.html

 

[Macterial Girl]

Mine is a late 2009 iMac. I though it would handle the upgrade, but maybe not? So my only choices are to roll back my OS or upgrade to a later model, (which can't happen any time soon...)?

 

[m.g.mcc]

Would a "USB 2.0 to Gigabit Ethernet" adapter be worth a try? Obviously, speed would be limited to the 480Mbps of USB 2.0, but that's faster than your Internet speed. I used one of these on a Windows PC that only had 100Mbps Ethernet, which was slower than my broadband.

 

[Macterial Girl]

Holy cow. I took your advice and purchased an Inateck 3-port USB 3.0 hub gig ethernet converter. Plugged it in and voila. It automatically went to 1000base T and my speed test is 89.96 down and 12.14 up. What a difference!! Thank you all for your advice!