Extremely slow upload speed wired

Hi. I'm getting less than 1mb/s upload speeds on a wired connection. YouTube videos are barely buffering. My PC is a beast, one year old and running windows 11 and top of the line specs. Network adapter is Intel i225-v. I'm wired into the white spherical verizon router and have tried multiple ports. If I wire direct into the modem, upload speeds are back to normal.

Also, my 7 year old laptop is getting reasonable upload speeds, both on wireless and wired in (windows 10).

I have tried the following :

-rebooting modem and router

-Going through Verizon's reboot process on the phone

-disable/enabling network adapters in device manager

-uninstalling the Intel network adapters in device manager

-a network reset

- disabling TCP checksum offload (ipv6) and disabling udp checksum offload (ipv6)

Any thoughts/suggestions here?

Accepted answers

Cang_Household

There was another user using I225-V and has the same problem. The TCP/UDP checksum offload fix for 1G/10G Intel chip is NOT applicable to 2.5GbE interfaces as this is a hardware issue with I225-V.

That user ended up buying a $18 Realtek RTL8125 PCIe card that fixed the issue without adjusting any settings.

All comments

Cang_Household

There was another user using I225-V and has the same problem. The TCP/UDP checksum offload fix for 1G/10G Intel chip is NOT applicable to 2.5GbE interfaces as this is a hardware issue with I225-V.

That user ended up buying a $18 Realtek RTL8125 PCIe card that fixed the issue without adjusting any settings.

TraderMatt17

Thanks I'll look into that card.

For my understanding, do you know what changed that caused this? Was this a Windows or Intel driver update? Or did Verizon change something? Really frustrating that I can't watch YouTube on a $4k PC, wired into 1gb internet and an ancient laptop works via wifi.

I would also be ok buying a different router if this would fix the issue. Have found the range underwhelming on the Verizon router.

Appreciate the help

gs0b

@TraderMatt17 wrote:
For my understanding, do you know what changed that caused this? Was this a Windows or Intel driver update? Or did Verizon change something? Really frustrating that I can't watch YouTube on a $4k PC, wired into 1gb internet and an ancient laptop works via wifi.

Verizon finally enabled IPv6 starting earlier this year. They've been rolling it out CO by CO throughout the year. It must have recently been enabled in your area.

Some Intel Ethernet chips have an IPv6 TCP and UDP checksum offload in hardware. The hardware offload will silently drop packets if their checksum calculation fails. This happens when packets are correct but have spurious data append at the end.

Fios ONTs append spurious data to the end of IPv6 packets.

So, if you have an effected Intel Ethernet chip, connect by Ethernet, and have Fios; lots of packets are dropped.

We can argue all day long about who's fault this is; Intel for releasing chips with this problem since they announced it in 2017 or Verizon for using ONTs that append spurious data to the end of packets. But that doesn't change the fact that the problem exists for the users who have this particular hardware setup.

The solution is to turn off hardware checksum validation, as software validation handles the ONT's packets just fine. Unless you're running a server that uses full bandwidth all the time, there is no performance degradation. Especially if you have a "beast" of a CPU.

However, it appears that disabling hardware checksum for some of the 2.5Gb Intel chips doesn't fix the issue. In that case, replacing the chip is the only option. Cang_household can comment more on this, as they've investigated it more than I have.

Here's Intel's report on the issue:
https://www.intel.com/content/www/us/en/download/19174/disabling-tcp-ipv6-checksum-offload-capability-with-intel-1-10-gbe-controllers.html

TraderMatt17

Thanks for the explanation. I don't fully understand why wiring direct into the modem (rather than the router) fixes the issue. If replacing the Verizon router with a better one, that also has more range, would fix this issue I'd do this.

TraderMatt17

Cang, thanks for your help. I bought a PCI e realtek adapter and I'm getting 800 +down/800 up.

[Deleted User]

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.

Dfaith

I had the EXACT same issue!!!!!!!! man I'm just glad to get an actual explanation

Dfaith

thank you so much for putting this up here, I was so lost and this issue is so rare it was impossible to find someone having the same issue

Motherboard Asus Prime X570-pro
SSD Samsung 970 Evo plus
Cpu Ryzen 9 3950x
Gpu Msi rtx 2060 gaming z
64 Ram Corsair vengeance

smith6612

Just to add onto this post. The Intel I225-V has multiple revisions/steppings. I know the Intel I225-Vs with Stepping 0 and Stepping 1 were prone to this hardware issue. Stepping 2 and beyond are supposedly the "bug fixed" versions which, still suffer from the IPv6 Checksum bug, but don't have the other silicon bugs. The user can tell what stepping they have by looking at the Device Manager, and looking for a number at the end of the Ethernet Adapter's name. For example: Intel Ethernet I225-V (2) would be a Stepping 2 chip.