March 1, 2011

Reviving Dead Ethernet Ports

Does your OnBoard Realtek Ethernet port seem dead ?
Can't you get it working on any Operating System ?
Are you getting the dreaded "Self-Assigned IP" ?

If so, this post is for you...

Many people contact me with issues getting their LAN working.
Some ever though of replacing the motherboard as the LAN appears to be "dead".

In most cases, it's nothing to be afraid of... The "Dead Realtek NIC" symptom is quite common on Gigabyte boards (among others), and, usually, there's no need to RMA it, nor hurry and buy a new NIC or Motherboard.

Just follow this procedure, testing again after each step, until your NIC is working again:
  1. Verify that the Ethernet port is clean of dust and lint
  2. Check your Ethernet cables are working
    You might want to try the cable with another computer, or try another set of cables
  3. Check your switch/router port is functional (might want to try a different port)
  4. Verify that LAN is enabled in your BIOS
  5. Unplug your PC, and leave it off for a couple of minutes. Then plug and turn on your PC, enter SmartLAN in BIOS.
    Most of the times, this solves the issues !
  6. Clear CMOS and reconfigure BIOS
  7. If it still doesn't help, reflash BIOS, and reconfigure your BIOS.
By this time, your NIC will probably be OK.

Still having problems ?
Leave a comment below and I'll try to help !


  1. This happens to me once in a while. I thought I had a defective board, but now I'm glad that it's a common problem.

    My solution is to leave the PC on and unplug the router for 10 minutes or longer.

  2. Great post. Often I see posts from folks having just these problems you describe. Your article would be just the right help for them. Problem how do you get it in front of folks maybe a FAQ entry somewhere? If I see their posts with this problem I will refer then to your article but I'm just one person. What's a more effective way?
    This is perhaps a generic question applicable to get good solutions in front of folks so they don't need to post. Unfortunately they might not know how to configure their search effectively [if they do search!]

  3. @anonymous: Thanks for your comment !
    Spread the word on Facebook, Twitter, etc.
    I've set up a shortened URL:
    Memorable, isn't it ?

  4. In resent year my internet seemed to get slower.. at first it was just 1mb loss in speed then after 5 months or so i remembered i need to clean internal PC dust because fans were clogged and PC started to overheat and shutdown unexpectedly. So after i finished cleaning PC inside and outside plugging everything back i noticed that Internet cable isn't plugged (Shows on task bar) I verified and double checked that both powerline and ethernet cable is in its port.. Lol i even pushed harder and after i took it out for third time i noticed 1mm dust clog on the tip of cable metal contacts.. So after having 400kb/s of speed it jumped to over 7.4mb raw download speed. Another Symptom was that after you turn on PC it takes a while for internet to become responsive.. from 5 to 40 minutes. Lol dust conducts internet?

  5. i tried all these steps, and I can't seem to get my NIC card to work again. It was working on first install, then after I shut it down and turned it on the next morning, the NIC was not work. It shows up on the hardware, but wont get an IP. Any thoughts?

  6. @afalcone4: Which OS ? Are you using the right drivers ? Does your NIC work under other OSes on this machine ?

  7. I have just installed 10.6.7 and my Realtek 8102E don't working in my hp dv5.

    I used the lastest version of Reeltek driver in offical site but nothing right!

    In 10.6.3 everyting is ok! Please help! Many thanks!

  8. @Anonymous: Does your 8102E still work on 10.6.3 or under other OS ?
    If so, try reinstalling the Realtek driver.

  9. Thank you very much, finally I can now get my ethernet working with lion.

    Any chance of porting the Intel centrino WiFi driver to OS X too? Most sandy bridge laptops are using these cards and it would be wonderful if we could get them to work.

    Check this:

  10. @Joseph: Glad it works !

    As for porting the Centrino driver, I agree it's a good idea...

    But, I have no additional bandwidth for that at the moment... I can barely work on the RTL81xx...

  11. When I run SmartLAN it detects that their is a cable and the link speed is 1 gbps but when I boot into OSX lion it says their are no pci ethernet cards installed. In windows I can't access the internet either.

    The green light that usually glows around the port doesn't even turn on when I plug in the cable. I am using the latest bios for the GA-P67A-UD4-B3

  12. @Anonymous: Which driver are you using for your NIC ?
    If I remember correctly, the GA-P67A-UD4-B3 uses a newer hardware revision of the 8111E that is unsupported by my RTL81xx kext v0.0.67+.

    However, as you can't access internet on Windows either, that could be a different problem...
    I'd start by checking in Windows that the NIC is recognized, and that you are able to ping your router, etc.

  13. I am using the "official" driver available in Multibeast 3.8. So the problem is not in OSX or windows.

    It fixed itself after I tried 2 different cables (However I am sure the the previous two were functioning.) Then when I moved the system to a new location, it no longer worked.

    The problem first occurred after I experienced the cmos reset error that can be caused by the AppleRTC.kext in OSX. Since then I reflashed the bios and reset the cmos and followed the rest of your guide

    Do you think that the cmos reset was the cause of the problem or is it just a coincidence? If it is some kind of error that I can fix, that would be great news, otherwise I'll just have to keep trying what you said.

    Also you mentioned that their are different hardware revisions. My other system has the earlier one (using your driver) and has not had any problems. Is this dead NIC bug only found in the newer revision?

  14. @Anonymous: As it 'fixed itself' after switching cables, it can also be related to dust or debris on the Ethernet port.
    Or it might be due to poor-quality/too-long cables.
    As you reflashed your BIOS, I don't think it might be related.

    The "dead NIC" problem is not isolated to newer hardware revisions... It's been there for a very long time, on multiple NICs and motherboards.

    I hope you'll be able to resolve it.

  15. For an unknown reason, the LAN port of my Gigabyte GA-H55M-S2 motherboard stopped working.
    Found your posted solution. Try it and it works.
    Follow all steps. Must clear the CMOS twice and reset SmartLAN. While SmartLan not giving the same detection messages as before the LAN port stopped but the LAN port is usable again. May be this a bug in the BIOS?

    Thank you very much.

  16. Im having this problem every time that I use Parallels, the Lan card is working, after I run some VM with Parallels and close VM the lan card dead.

  17. @Anonymous: The symptoms of the "Dead NIC" are that even after rebooting, you are unable to do any communications (not even get a DHCP address).

    It's different from the lost network after using VM, as this usually can be solved by disabling and re-enabling the controller in System-Preferences (or unplugging and re-plugging the cable).

  18. I didn't know this and gave my motherboard to Gigabyte and its for ever for them to repair the motherboard. I should have read this post.

  19. I'm having trouble with my NIC,
    it went on and off, most of the time
    like searching for connection in the smart-LAN even when it is unplug, is it supposed to be like that?

    i hoped your solutions will be helpfull


  20. @Anonymous: Yes, the SmartLAN keeps running indefinitely, trying to identify the link...
    But, if cabling/router is OK, it should detect it.

    Good Luck, and please update if this procedure helped.

  21. Yes, you can also think to initialize your card with Windows which is still can be necessary with bogus BIOS.

  22. @Anonymous: For that you have to have Windows.
    Also note that several users reported this issue on Windows as well.

  23. I have the dreaded "Self-Assigned IP" about 70% of the boot times. So its just rebooting until it works. I know a thing or 2 about these type of issue. This sounds to me like an chipset initialisation or chipset errata that needs to be worked around in the driver. My guess is Realtek doesn't supply an errata sheet?

  24. @Locmer: This definitely sounds like an initialization issue, and unfortunately, it affects users of all OSes and seem unrelated to driver...

    I'm not aware of any errata sheet from Realtek (but I'm not under NDA).
    On the other hand, it even affects those using the official Realtek drivers on Windows, so...

  25. @Lnx2Mac I looked into this some more because it drove me nuts. And I found this link:

    which makes total sense to me. It looks like the MB and the network chipset get into a locked up state that the driver cannot reset it out. I think draining the power from the MB so the chipset resets is the thing that really needs to happen to reset this state. (Wake on Lan = on, will surely keep the network chip active while the computer is turned off)

    So adding to your list on the top of this page:

    - Disable wake on lan in the Bios
    - Remove power cord
    - Remove Network cable
    - press the power on switch to drain the capacitors and any remaining power in the PSU
    - wait 5 minutes (I'd like to test if this is really needed)
    - plug power cable back
    - plug network cable back
    - press power switch
    - press thumbs ;-)

    I am not sure if all steps are needed but this does it for me.

    May be I'll sign the NDA @ realtek to see if there is a way to software wise reset the chipset to get it out of this locked state.

  26. Hello, I have had my hackintosh working for quite a long time. I have the x58-ud3r 2.0 motherboard and my lan has been working for a very long time. However, I just installed a wireless card from a macbook pro (BCM94321) through a pci adapter and now nothing is working. Both the wireless and Ethernet is being "detected" and can connect but cannot assign an IP address. I tried installing your driver and than did the motherboard steps, but nothing is working. I am really at an im-pass, I was wondering if anyone had any ideas or anything?


  27. In addition to my last comment, could peerguardian or little snitch be conflicting with something?

  28. @HsingH: Have you tried removing the configuration for the Ethernet and Airport interfaces, and adding them back ?

  29. I have RTL8139 but connection is unstable in Lion 10.7. After boot sometimes it shows connected and sometimes it shows not connected (cable unplugged). How to fix this problem.

  30. I don't know how to get this onboard ethernet to work. I tried your steps and the motherboard recognizes that it's plugged into the router, it can even tell how long the different cords I try are and whether I'm plugged into my 100Mbps router or my gigabit router, but once I boot into W7 or 10.6.8 it doesn't work, but two different things happen. When I boot to Windows the lights don't even go on when I plug the cable in. In Snow Leopard however, the lights go off but for the life of me I can't get the thing to recognize that there is an ethernet cable plugged in. I've tried clearing CMOS, flashing my BIOS, reinstalling the 81xx, and whatever else I can find on the internet that has worked for others. Oh and I have a GA-Z68X-UD3H-B3 mobo by the way. I have been successful in getting my PCI WLAN card to work to get me on the internet before but not in a way that allows me to get the App Store to work (I get the error saying that this computer could not be verified) so thinking that this may be blocking the onboard ethernet from working, I deleted that stuff trying to get the ethernet port to work. I try not to bother people on forums because after a little more digging I usually figure it out and learn something, but I am starting to get frustrated seeing post after post of success stories with my motherboard that I can't seem to attain myself. Sorry for the long post but I try to tell as much about the problem as I can so I don't waste peoples' time in the long run. Thanks for the initial post I hadn't really found a good place for this comment to go where I thought I'd get some real help and you really sound like you know what you're talking about! Thanks in advance for the advice.

  31. @Tapash: Which kext are you using with your 8139 ?

  32. @infangec: Your GA-Z68X-UD3H-B3 is fully supported by my RTL81xx.
    As it doesn't work even in W7, I suspect something else is causing the trouble.
    I'd start by temporarily removing unessential stuff (e.g. the PCI WLAN card) to see if there's a conflict.
    Then once you get it working, start adding the cards back one by one to find the conflicting one.
    Good Luck !

  33. I installed your driver via MultiBeast on 10.6.8, and can't get ethernet to work.

    What I have:
    RTL8111E (on this mobo )

    What I see:

    * In SysPrefs > Network > Ethernet, 'Status' is 'cable unplugged' although it's plugged in and the light by the port on my motherboard IO port's on. (Using DHCP)
    * In System 'en0' shows up as an active service under Network. That's the only reference to it I can see in System Profiler.
    * In Network the first screen ('Choose network port configuration') the Ethernet radio button's greyed out.

    The results of trying your numbered steps:

    123 - all done

    4 - the only reference I can see to enabling LAN in my Bios is Integrated Peripherals > Onboard H/W LAN which is Enabled.

    5 - I've entered SmartLAN in BIOS, it loops through this text, which suggested the cable is registered, and my mobo manual says shows the cable's functioning normally:

    "Start detecting at Port.
    Link detected -> 100MBps
    Cable length less than 10M.

    6&7 - Can I safely try these now, or is there something else I should try first given my situation described above? Eg. any commands I can run to check your drivers are installed OK?

  34. @tog22: Could be an autonegotiation issue with your 100MBps switch.
    Try specifying your Ethernet configuration manually (In System Preferences | Network, select your Ethernet adapter, and in Advanced, go to the Ethernet tab).
    Also, make sure you installed v0.0.90 of my kext, as your NIC is probably unsupported under v0.0.67+

  35. @Lnx2Mac

    Thanks, in the end I fixed this by just downloading and installing the driver direct from your site rather than using the MultiBeast version. Might be worth suggesting people do that in the future!

    Thanks for all your work :)

  36. Lnx2Mac... you are a life saver. Problem was solved at number 5. I didn't think of unplugging it and letting it sit for a little. I thought it was strange because the link lights on the devices plugged into my computer were lighting up, but the link light on the motherboard wasn't.

    It was bad timing for me too. My computer was working, then I put it to sleep and removed my old router and installed an Airport. I was thinking all kinds of things like the Airport was broken or the 'Hack' couldn't take Gigabit, but I guess it was a simple fix.

    Thanks so much.

  37. Hi, thanks for all of your work..

    I have a problem however. My ethernet port does not work in either osx or win7.

    It initially worked for a bit on osx right after upgrading to 10.7.2 and using multibeast. However, it wasn't booting up from the harddrive so I tweaked more settings. I'm not sure what I did wrong, but now the ethernet port is completely dead. Does not even show up as an option in the dropdown menu in osx and is not detected in win7 at all.

    I tried your above steps and I even reflashed the bios. It still hasn't worked. I'm completely at a loss.

    My board is z68xp-ud3. Hopefully you have some suggestions? I don't think the port is bad because it did work, just not anymore.

  38. @Will85: Have you tried unplugging the PC and letting it discharge for about 5 minutes ?

  39. Hello,

    I have a 8101E Network Card. And a H61ML Board. My Bios doesnt have the Smart Lan Option (AMI Latest Bios 2011). I can only Enable/Disable/Auto
    the Onboard PCIE LAN, PME Wake up S5 and Ring-In Wake up S5.

    I tried them all... No idea what else to try.
    I use the latest official Nic.
    When I boot into Windows or the Ubuntu Live CD, my Internet works perfectly. Same thing for my Windows Laptop.

    I am having this problem for about 4 days now. I just can't seem to figure it out.

    I have a post about this:

    Any Suggestions?
    Any Suggestions?

  40. I have been using your 0.0.90 driver ever since it was released. It has basically been working great. Thanks!

    I have been very puzzled by the Wake-On-Lan functionality, though, as it appears to work and then suddenly stop. In the past I have tried switching drivers and CMOS resets, etc. with no real success. Recently a power outage appeared to suddenly fix the WOL again.

    I noticed it wasn't working again the other day and I tried the unplug for a while trick with no success, then I re-read this post and noticed the 'go into SmartLAN in the BIOS' part. I was able to fix it again by doing that (I am typing this post remotely after having woken the computer up).

    So my current solution to fixing my WOL, should it stop again, will be 1) power-off, 2) unplug, 3) rest for 5 mins, 4) reboot and enter SmartLAN in BIOS.

    The basic network functionality has always worked, it is just the WOL that goes away.

  41. so i instralled
    RealtekRTL81xx.kext v0.0.90
    but i can't use Appstore & iCloud & facetime..lan teaming.
    it syas: "Your device or computer could not be verified. Contact support for assistance.".
    internet works fine.
    first of all i use GA-x58a-ud5 rv2.0 FD, MOBO.
    i have tried to change
    NetworkInterfaces.plist (seems to be locked or overwrite every reboot?)
    ioBuiltin is false
    i saved as true and then reboot
    its changed into false.
    so i chcked
    my network utility shows Ethernet adaptor(en0)(en0) & (en1)(en1)
    which is not right..
    also i chcked (sys. info.) there is no path or location to Lnx2Mac's Realtek RTL81xx...

    so im wondering if i delete Lnx2Mac's Realtek RTL81xx
    but i can't find realtekrtl81xx.kext
    in S/L/E

    any suggestion??

  42. @Anonymous: As your NIC works on Ubuntu and Windows, the issue you are having is with the kext, not related to a "Dead NIC" per se.

    I think that for the 8101E, your best option is the Official Realtek RTGMac kext.

  43. @Anonymous: Somehow, 10.7.2 broke the WOL ability of my kext for many (me included).

    Thanks for letting me know that SmartLAN also helps recover that!

    I'll recheck on 10.7.3, and still have to work-around that WOL issue.

    Thanks again for your comment !

  44. @irakura:
    The "Your device or computer could not be verified. Contact support for assistance." message almost always refers to a misconfigured network.

    1) Make sure your /Extra/org.chameleon.Boot.plist has the following:

    If not, add it, reboot and check if it's fixed.

    Still no luck ? Move on...
    2) In System Preferences | Network, remove all interfaces by using the [-] button.
    Then delete (but first, you'll want to keep a backup) your /Library/Preferences/SystemConfiguration/NetworkInterfaces.plist file.

    Again, reboot, add your Ethernet (and may be other network interfaces) in System Preferences | Network.


    Still doesn't help ?

    3) You might have to add
    to your /Extra/org.chameleon.Boot.plist.
    Depending on your system, you might need to use a 0 instead.

    Regarding the path to RTL81xx kext, it should be in /System/Library/Extensions/RealtekRTL81xx.kext. Are you using my installer package ?

    Good luck, and please report back on your progress !

  45. Thanks for this post, I must have turned my LAN off in the BIOS ages ago, since I have a AirPort card for Wifi! :D

  46. Mine turned out to be dust. I would never have thought that was the case. Thank you for posting.

  47. Dear @Lnx2Mac

    I have a probelm,for me it says i have no internet conection available. i have a onboard card, and i find the driver on device manger, and it all says it's ok, and is says that the driver is ok to. no fault message at all. I have tried all your steps, but nothing works. The link lights is of when the computer is on, but bliks orange when the computer is off. Earlier on the old router it worked fine, but when i got a new router with higher speed it stopped working. So i tried the same cable on another computer and it worked fine..

    so if you could help me it would be so gratefull. just let me know if you need some more info, and i will see if i can help.

    i have a Asus P9x79 PRO motherboad, with Intel(R)82579V Gigabit Network connection
    And Intel(R) Network Connections as the driver
    and my Os is Win 7 pro

    1. @bjørn olav loftsgarden:

      Does the new router work OK with the other computer ?
      Try interconnecting the computers directly (not through the router) and see if it works.
      Or try using a switch/hub between your machine and the router ?

  48. I solved my problem using this method.

    My setup is:
    0.90 lnx2mac driver
    h67m-d2-b3 RLT8111E
    Mountain Lion 10.8.1
    Multiboot: MBR table: win7, linuxmint, osx all on 64bits

    Somehow my connection was capped at 1mbps: Testing with Internet only, then Network only and in the end both at the same time. All of the tests were capped. I used istats menu to check out the cap. When I went back to win7 I realized it was capped aswell (checked with netlimiter).

    Now I knew my NIC was dead. Used the LAN ports scanner utility on the bios and my gigabit connection was working on a 10BASE-T.

    In the end got here and did what was told and it somehow revived and now working fully on all of the operating systems.

    Lnx2mac you're the man! porting the 8111E without a mb with that chipset was boss.

    1. @Jonathan Montesinos, glad it helped !

      Thanks for your comment !

  49. This used to happen occasionally with my gigabyte g31m-es2l running snow leopard. The solution was to take the CMOS battery out and clear it. The other steps described in this article was irrelevant to my particular motherboard.

    1. Yes, that's another way to completely clear the CMOS.

  50. I have a newer realtek 8111DP on a gigabyte B75M-D3P. I was having connectivity issues and have narrowed it down to speed. If I leave it at 100Mbps it works fine under windows, OSX etc. Once I move it to GigE it has all kinds of issues. It sometimes is slow or will not connect at all. I have tried everything under the sun, I even replaced the motherboard, I also have updated bios, changed cables, cleaned the ports etc. Nothing seems to help. I think it might be related to noise from another component in the system but even removing my big Graphics card did not seem to change the behavior. My next course of action was going to be move the power supply out, but I was curious if you have any issues like this or recommendations.


    1. Mike, that could also be a router problem...

    2. Wow, excellent you are good. I setup internet sharing on my laptop and connected and the issues were gone.(laptop acting as new pseudo router) I was thinking this was a possibility, but was waiting to try it last. I am using an older small-business Cisco/Linksys router that has worked great for years. Guess it maybe be time to replace it unless you can think of something that is misconfigured, have never had issues with probably 15 other gigE connected hosts over the years. Anyways thanks for the great advice at least now I have the root cause. I never got around to trying the power supply so thanks for saving that effort.


  51. Hi Lnx2Mac,

    Thanks for great driver first.

    I'm having an issue with 0.90 driver with Zotac H77ITX-A-E (should be: 8111E). After power on system, it works fine. But after few sleep/wakeup, it keep getting self assigned IP address. Reboot will not help.

    I had to shut the system down, and unplug power supply, and replug and start system to get it work again.

    Another way to make it work without unplug power supply is: change system definition (smbios.plist) and reboot.

    My guess is: after change system definition, OS will reapply/reupload firmware?



    1. @Wei Gao: Sorry to hear about this. Unfortunately I have no experience with this Zotac mobo... Could be something funny with its BIOS.

      Regarding firmware, my driver loads it every single time the machine boots, so don't think it's related.