Little or no upload speed with Fios

[ejkkjh1]

Fios has little or no upload speed.  This is intermittent, sometimes ok but lately almost all the time.  I have tried many speed test apps either on my computer or via a browser, all same results.  Download speeds are around 700 to 800 Mhz but upload is zero.  So interacting with a web site or sending email does not work.  Just like trying to post this message, takes forever and multiple tries.

I have spent hours in Verizon tech chats with several techs.  Only speed test they will accept is the Fios one, which never shows an upload speed problem, but at least a dozen other speed tests confirm little or no upload speed.  Tried calling Verizon, do not get a call back or wait for hours with no help.

I have tried 4 different computers, same problem.  Changed cables, all tests wired to router direct.

No idea what to do next.  Any help is appreciated.  Thank you.

[dexman]

Was the cable between the router and ONT swapped?

[smith6612]

How long ago did this start? Within the last few months? Only on wired?

[ejkkjh1]

Started within the last couple months, more or less.

[ejkkjh1]

About a couple months ago, not exactly sure.

[Cang_Household]

Go to your adapter settings and disable IPv6 TCP Checksum Offload. Then test again.

[ejkkjh1]

Can not find this setting in the router, please let me know where to find it.

Thank you

[Cang_Household · Accepted solution]

Adapter setting means the network adapter setting on your computer, not on the router.

The issue you are facing is common among users using Intel NICs. Intel has acknowledged this problem/bug since 2017 and a solid fix is not possible. The current workaround is to disable IPv6 TCP Checksum Offload in adapter settings.

Or, the lesson here really is avoid buying Intel NICs, or computers and motherboards that come with Intel NICs.

If it is not clear yet: The issue you are facing is likely not directly Verizon related.

[ejkkjh1]

Really appreciate your help.  After I sent the last reply realized you meant the network adapter in my computer.  I changed that setting and all appears to be working great.  I do have an Intel NUC, it has always been very fast but something must have changed recently.  Sometimes I had no upload speed at all, this affected sending large emails, logging into web sites, viewing sites that were previously very fast, like Amazon.  Since I made the change last night, was able to log into a .gov site for first time in weeks.

Thank you very much.....  Emory

[ejkkjh1]

Also, FYI - I have an older Dell desktop, it is an older I7, about 5 or 6 years old, it had same problem, little or no upload speeds, could not log into some sites, etc.  I changed that setting in my network adapter and it now works great.  Never had this problem with it until recently, so maybe Verizon changed something.  It is not a intel nuc.  Thanks again....

[gs0b]

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@ejkkjh1 wrote:

 Never had this problem with it until recently, so maybe Verizon changed something.  It is not a intel nuc.  Thanks again....

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Verizon is in the process of enabling IPv6 across the Fios network.  Many locations went live with IPv6 in June.  Certain Intel Network Interface chips/cards (NICs) have a long standing bug that prevents them from properly handling IPv6 checksum offload.  This hasn't been noticed by Fios users before, as IPv6 was not enabled.  Now that it's available, users with the buggy Intel NICs are having issues.

The solutions are to turn off hardware checksum offload, get a new NIC or get a new computer with a new NIC.

[LawrenceC]

I would like to thank everyone for taking the time to post your comments and opinions related to this topic. This topic has been thoroughly discussed and will now be closed. Please feel free to open a new thread for further discussion. Thank you.