Solved Atheros AR8151 Ethernet connection not working

I recently upgraded to Windows 8 Pro x64.

My wireless connection is fine, but my LAN isn't. This is a university subscription so there is a proxy server. I asked the school if they have activated my subscription and they said yes. I tried changing cables but it still would not connect. I know the proxy server settings are correct because there is also a wireless connection in school which uses the same settings.

I ran network diagnostics and it said that the connection between the cable and the internet is not working. When I open Chrome, it says that the DNS lookup failed. I tried resetting my TCP/IP, setting my preferred DNS address to 208.67.220.220 and 208.67.222.222 but it still would not work.

I check my ethernet driver settings in Device Manager and it is fine and updated to the latest version.

I was just wondering what is really wrong with my computer and how it can be fixed. Thanks

I'm having the same issue. This was working under Win 7 x64. I just upgraded my Asus G75VW to Win 8 Pro x64 and the Atheros AR8151 GigE interface is in a disabled state. Right clicking and selecting enable does nothing, still disabled. Device status states this device is working properly and is using driver version 2.0.0.4 2/15/2011 under C:\windows\system32\drivers\L1C63x64.sys.

EDIT: I fixed my issue by upgrading the AR8151 driver directly from Qualcomm. You can access the drivers here:
Qualcomm Atheros :: Corporate :: Customer Portal

I fixed it by uninstalling Connectify Pro. Somehow it's in conflict with my ethernet driver :O

I have a Medion E7220 MD98740 laptop from Aldi (the German supermarket chain). It has an AR8151 gigabit Ethernet adapter. Under Win 7 it worked OK at 1 Gigabit but under Win 8 the best I can get is 100 M bits / second. I can't even force it up to 1 Gigabit as the setting for that is not even there. I have tried uninstalling etc. and went and got the latest driver from Qualcomm as cruiserman did but still no fix.

I have the same issue. Atheros LAN driver on my ASUS N73SV. Tried installing the version of the Atheros site, no luck. Just tried the version that came with the PC when it had Win 7 on it, no luck. This is SO frustrating. Wireless seems to work at a reasonable speed. Wired does not work. The best I can get with wired is about 100 kb/s - brutal. Any updates from anyone?

The only way I could fix this was to reinstall Windows 8. I don't know where things went wrong but I have been busy reinstalling all my software. The only thing I have done differently so far is that I have not transferred my local user account to the domain account for my home network. Perhaps something got messed there. I don't know. We will see ...

I have the same issue under win 8 - Atheros AR8151 - not connecting and won't recognise the LAN cable plugged in, same one which works fine under win 7. I have updated the driver but no change, will look for conflicting software. Fortunately I can boot into 7 if I need LAN over wireless.

GirlieBiker said:

I have the same issue under win 8 - Atheros AR8151 - not connecting and won't recognise the LAN cable plugged in, same one which works fine under win 7. I have updated the driver but no change, will look for conflicting software. Fortunately I can boot into 7 if I need LAN over wireless.

Click to expand...

EDIT: I fixed my issue by upgrading the AR8151 driver directly from Qualcomm.

You can access the drivers here:

Qualcomm Atheros :: Corporate :: Customer Portal

Im having similar issues. although my AR8151 sees connection my upload speeds are painful. im getting 0.47mbs compared to my old laptop over wireless 4.87mbs.
I wanted to re install the driver but im not sure which one it is on the drop down list from the link above.
Can someone please help me. Very much a noob.
Cheers

possible solution

MrTiff said:

Im having similar issues. although my AR8151 sees connection my upload speeds are painful. im getting 0.47mbs compared to my old laptop over wireless 4.87mbs.
I wanted to re install the driver but im not sure which one it is on the drop down list from the link above.
Can someone please help me. Very much a noob.
Cheers

Click to expand...

Dear All,

I also have the AR8151 at my ACER Laptop and have serious issues with the upload-speed (~30kbs) to a Synology NAS. I was checking several web-sides over the last few days and final found a very good tip on a German site, which brought the speed up to ~35mbs.


The setting "Large Send Offload (IPv4)" at the Network adapter needs to be deactivated. Note, I’m not an expert in network-settings and don't know what the setting means. However, after I have done this on my laptop the speed was brilliant.

Hope this helps you as well.

Cheers

gregstrei said:

Dear All,

I also have the AR8151 at my ACER Laptop and have serious issues with the upload-speed (~30kbs) to a Synology NAS. I was checking several web-sides over the last few days and final found a very good tip on a German site, which brought the speed up to ~35mbs.


The setting "Large Send Offload (IPv4)" at the Network adapter needs to be deactivated. Note, I’m not an expert in network-settings and don't know what the setting means. However, after I have done this on my laptop the speed was brilliant.

Hope this helps you as well.

Cheers

Click to expand...

You are the BEST !!!
I have a Dell XPS 15z with the same adapter.
After upgrading to Windows 8 (from 7 Pro), my Ethernet upload speed fell to about 30k... VERY frustrating.

Dell support was useless. The first thing they told me was that their warranty did not cover 'speed optimization'. I explained that this is not 'optimization', this is 'fixing'!! The only way I could convince them of this was by telling them that my upload speed was fine when the computer had Windows 7. After putting me on hold for a long time, they came back on the phone and basically said "Sorry, your laptop shipped with Windows 7. We don't have a driver for Windows 8". Basically, they told me "tough luck have a nice day"

I went to the Atheros website and found the updated driver for Windows 8 64-bit. I thought for sure that would fix it. No luck. After several uninstalls / re-installs / reboots and cursing, I started thinking I would have to rebuild my laptop from scratch.

But ... I came across your post, and guess what ... IT WORKS!
I can't tell you how happy I am now. You made my day ;-)

Danke schön!

gregstrei said:

I also have the AR8151 at my ACER Laptop and have serious issues with the upload-speed (~30kbs) to a Synology NAS. I was checking several web-sides over the last few days and final found a very good tip on a German site, which brought the speed up to ~35mbs.

The setting "Large Send Offload (IPv4)" at the Network adapter needs to be deactivated. Note, I’m not an expert in network-settings and don't know what the setting means. However, after I have done this on my laptop the speed was brilliant.

Click to expand...

Gregstrei, my German favorite neighbour, I love you! After update from Win 8 to Win 8.1, uplink speed was very poor. I tried everything like installing the newest driver form qualcomm directly - nothing worked - until I found your post. Everything is fine again!

Thanks Gregstrei, thanks google! And shame on you, Microsoft!

BTW: here is what this setting means: Network Connectivity — Advanced Settings for Intel® Ethernet 10/100 and Gigabit Adapters

The latest driver for AR8151 seems to be http://www.qca.qualcomm.com/drivers/AR813x_AR815x_AR816x_v2.1.0.21_WHQL.zip