Hyper-V External Virtual Switch Bridge Mode - Slow download speeds on 8265AC

[GrahamWharton]

Windows 10 20H2 19042.572

Intel 8265AC M2 with Driver 20.70.19.1

When I create a Hyper-V Virtual Switch in External Mode with my Wifi Adapter and enable the Bridged Mode option, my download speeds plummet but upload speeds remain consistent.

Please see the video of my testing. Any clues as to what to try.

https://youtu.be/LD2J0FfVXj4

[Alberto_Sykes]

GrahamWharton, Thank you for posting in the Intel® Communities Support.

In order for us to provide the most accurate assistance on this matter, we just wanted to confirm a few details about your system:

What is the model of the motherboard?

If this is a laptop, what is the model of it?

What is the model of the Router?

Is this a new computer?

Was it working fine before?

When did the issue start?

Did you make any recent hardware/software changes?

The wireless card, did you purchased it separately or did it came installed in the computer?

Which Windows* version are you using?

Does the problem happen at home or work environment?

Please provide the SSU report so we can verify further details about the components in your platform:

https://downloadcenter.intel.com/download/25293/Intel-System-Support-Utility-for-Windows-?product=91600

Any questions, please let me know.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[GrahamWharton]

What is the model of the motherboard?

The system is a HP EliteDesk 800 G3 Tower.

The Wifi card is an Intel 8265AC M.2 card part number 851592-001

What is the model of the Router?

Draytek 2862ac WPA2 2.4+5G. Wifi linked at 5G

Is this a new computer?

Not particularly new no.

Was it working fine before?

I've only just migrated to using Hyper-V from WSL, so this is the first time I have used the Hyper-V Virtual Switches.

When did the issue start?

The very first time I tried to use an external virtual switch in bridge mode.

The wireless card, did you purchased it separately or did it came installed in the computer?

I purchased it separately. The 8265AC card does however come preinstalled in some models of the Elitedesk 800 G3 Tower.

Which Windows* version are you using?

Windows 10 Business 20H2 19042.572

Does the problem happen at home or work environment?

Well, I work from home, but this is my business PC in my home environment.

SSU

Find attached

Additional Info

Note that this only occurs when I create an External Virtual Switch, linked to the Wifi Adapter, and tick the "allow the management operating system to share this adapter", i.e adding it in bridged mode. As soon as the switch is created, network performance in the download direction only is severely affected. Uploads are unaffected. This happens even when all Hyper V virtual machines are off.

[GrahamWharton]

Also note, If I connect to my router with the wired connection via the I219-LM onboard adapter and perform the exact same process then it works perfectly so I'm pretty sure it is linked to the wireless card/drivers.

[Alberto_Sykes]

GrahamWharton, Thank you very much for providing those details and the SSU report.

We will review the SSU report and we will do further research on this matter, as soon as I get any updates I will post all the details on this thread.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[Alberto_Sykes]

Hello GrahamWharton, I just received an update on this matter.

Just to let you know, we are still doing further research on this matter and we just wanted to confirm:

How many virtual machines are you using?

Besides what is showing in the video you shared with us, is there something else that you are doing with the virtual machines, like specifics tasks or processes? Please provide a detailed description of the steps you follow for the problem to occur.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[GrahamWharton]

I have a virtual machine setup for local web development. It just runs apache/php/mysql. I would like to have the virtual machine to use a virtual switch (linked to wifi card) shared (bridged) with my PC, and this is when the problem starts. As soon as I enable the "shared with management PC option" to enable bridging the download speed on the host machine plummets. Note that this even happens when the virtual machine is powered off. You will probably see in the video, as a workaround, I have created a second virtual switch linked to my wired card (unshared, so no bridging) and I am temporarily using a wired connection to my router exclusively for the virtual machine.

Note though, if I stop the virtual machine, remove wired connection, remove wired virtual switch, and just have the single virtual switch linked to wifi card, but shared with management PC, the problem occurs, so I'm 100% convinced it is not related to the virtual machine, or the second virtual switch.

I can run another video with all that disabled if that helps.

[Alberto_Sykes]

GrahamWharton, Thank you very much for providing that information.

We will continue with our research on this matter, as soon as I get more details I will post all of them on this thread.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[Alberto_Sykes]

Hello GrahamWharton, I just received an update on this matter.

In order for us to continue with the research on this topic, we just need to gather further details about this scenario, could you please fill the form below with the information requested in there for us to keep going with the investigation?:

Problem details

Problem description:

Frequency of occurrence (once an hour, day, always):

Computer power source (plugged in or battery):

Steps to reproduce (provide links to forums, online help, screen shots):

Attempted workaround (turn off settings, change power settings, etc.):

Environment (office, school, hospital, factory, home):

Client computer details

Computer manufacturer(s):

Computer model(s):

Windows OS (provide Version number if Win10, and 32- or 64-bit):

WiFi configuration manager (e.g. Intel PROSet, Windows AutoConfig (native), etc.):

WiFi adapter model(s):

WiFi device driver version:

Number of systems affected:

Wireless security method

Encryption Type (Open, RC4, TKIP, AES):

802.1X authentication type (WEP, TKIP, CCMP):

Key Management Type (PEAP, EAP-FAST):

WiFi network environment

Access Point manufacturer, model, & SW version:

Wireless Frequencies in use (2.4 and/or 5 GHz):

802.11n or 802.11ac enabled (None/HT(11n)/VHT(11ac)):

Channel Width (20 MHz vs. 40 MHz) for 2.4 GHz?

Channel Width (20 MHz vs. 40 MHz vs. 80MHz) for 5 GHz?

SSID stealth mode (hidden or broadcast):

Enterprise Customers:

WLAN Controller manufacturer, model, and SW version:

RADIUS Server Make/Version:

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[GrahamWharton]

Problem details

Problem description: Intel 8265AC Wireless card connected to Local LAN on Windows 10 Business. Upload and download speeds to speedtest.net show I am able to max out my internet connection 70MB Down 20MB Up under normal operation. If I go into HyperV Manager and create an External Virtual Switch linked to my Wifi adapter and set it to share connection with management PC (this is the key part), i.e to create a network bridge, then the download speeds are reduced to sub 1Mbit. Upload speeds are unaffected. As soon as I remove the Virtual Switch, original speeds are resumed.

Frequency of occurrence (once an hour, day, always): Always. 100% reproducable on this machine.

Computer power source (plugged in or battery): Plugged in

Steps to reproduce (provide links to forums, online help, screen shots): https://youtu.be/LD2J0FfVXj4

Attempted workaround (turn off settings, change power settings, etc.): At the moment Instead of creating an external switch with my wifi adapter, I create an external switch with my LAN card and do not set it to shared. Therefore my Virtual Machine has direct access to the LAN via wired adapter, instead of via shared Wifi adapter. This means I have a temporary cable run setup which I would like to remove.

Environment (office, school, hospital, factory, home): Office environment at home.

Client computer details

Computer manufacturer(s): HP

Computer model(s): EliteDesk 800 G3 Tower

Windows OS (provide Version number if Win10, and 32- or 64-bit): Edition Windows 10 Business Version 20H2 Installed on ‎28/‎04/‎2020 OS build 19042.572 Experience Windows Feature Experience Pack 120.2212.31.0

WiFi configuration manager (e.g. Intel PROSet, Windows AutoConfig (native), etc.): Settings via standard windows control panel.

WiFi adapter model(s): Intel 8265AC M2

WiFi device driver version: Intel, 15/09/2020 20.70.19.1 (I have also tried with latest HP driver)

Number of systems affected: 1 (I only have 1)

Wireless security method

Encryption Type (Open, RC4, TKIP, AES): AES

802.1X authentication type (WEP, TKIP, CCMP): WPA2

Key Management Type (PEAP, EAP-FAST): N/A

WiFi network environment

Access Point manufacturer, model, & SW version: Draytek Vigor 2862ac v3.9.4.1

Wireless Frequencies in use (2.4 and/or 5 GHz): 5Ghz. (2.4Ghz is disabled on AP)

802.11n or 802.11ac enabled (None/HT(11n)/VHT(11ac)): 802.11ac

Channel Width (20 MHz vs. 40 MHz) for 2.4 GHz? N/A

Channel Width (20 MHz vs. 40 MHz vs. 80MHz) for 5 GHz? 80Mhz

SSID stealth mode (hidden or broadcast): Broadcast

Enterprise Customers:

WLAN Controller manufacturer, model, and SW version: N/A

RADIUS Server Make/Version: N/A

[Alberto_Sykes]

GrahamWharton, Thank you very much for filling the form.

We will continue with our research on this matter, I will post all the updates on this thread as soon as I get them.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[Alberto_Sykes · Accepted solution]

Hello GrahamWharton, I just received an update on this matter.

After reviewing the case, we suggest that the following workaround may help optimize Hyper-V performance for you to take it under consideration:

Step 1. Go to Device Manager and right-click on “Microsoft Network Adapter multiplexor Driver” and select 'Properties'

Step 2. Disable LSO settings 'Large Send Offload Version 2 (IPv4)' and 'Large Send Offload Version 2 (IPv6)', as shown in the attached screenshot

This is based on one of the Microsoft articles about the recommendation to improve throughput by disabling TCP Offloading (including LSO), Disable TCP Offloading for the Virtual Machine Network Cards:

https://docs.microsoft.com/en-us/biztalk/technical-guides/network-optimizations

The content on the above site is not controlled by Intel®. This information is offered for your convenience and should not be viewed as an endorsement by Intel® for the merchants or services offered there

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[GrahamWharton]

Thanks for that Albert. That setting worked a treat

Best wishes, Keep safe.

[Alberto_Sykes]

GrahamWharton, You are very welcome, thank you very much for letting us know those results.

Perfect, excellent, it is great to hear that the problem got fixed after following the troubleshooting steps provided previously and now the  

Hyper-V feature is working properly.

Be safe as well, Best Wishes.

Any other inquiries, do not hesitate to contact us again.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel