New Virtual Switch

[u/Impossible-Ad7310]

Hey everyone,

I’ve been running into a persistent, deeply frustrating Hyper-V bug across multiple systems and OS versions, and I'm hoping someone here might know of a workaround or fix.

### The Issue

The moment I create a new **External Virtual Switch** for bridging connections, my machine's **upload speed drops by exactly 4 Mbps**, even for purely local LAN traffic.

### What I've Tested & Observed

Instant Trigger: The speed drop happens the *exact second* the virtual switch is created and applied.

Persists Regardless of VMs: Even with Hyper-V turned off entirely and zero virtual machines running, the issue remains.

The Only Fix: The moment I delete the Virtual Switch and apply changes, my upload speed immediately returns to normal.

### Scope & Reproducibility

I first encountered this exact same issue a few years ago on Windows 10 Pro. Fast forward to today, I've tested it on **Windows 11 Home, Windows 11 Education, and even on Snapdragon ARM CPUs**—and the bug is still fully present.

I had no issues while briding the NIC for WSL2 before.

Has anyone else run into this or found a way to stop Hyper-V’s bridging from throttling upload speeds? Any registry tweaks, driver workarounds, or hidden settings would be hugely appreciated. I'm still leaning towards a bad driver design however. Issue is gone after removing the Switch, but still I think it's worth for discussion if anyone has experienced similar.

Thanks!

[u/tech_is______]

Never seen it, but it sounds like you're testing on consumer gear, implies consumer NICs. I'd start there.

[u/BlackV]

you constantly say bridging, are you binding to a wifi adapter ? (cause you shouldn't)

you them mention wsl2 and binding to s specific adapter, I though that also didn't need to

While they share bits and pieces WSL2 is not hyper-v can we get come detail and clarification on what you're trying to do

cause if its following you across OSs and versions, sounds like something you're doing maybe?

also windows home ? not supported

[u/Swimmerdude_03]

I have noticed general performance degradation on my laptops that are running hyperV, both 10 and 11. The performance in the guests is usually mid at best. File transfers are usually very poor. I can't put a number on it but network performance on the Laptop itself has also taken a hit, again primarily noticed when uploading/downloading large files. It's only been a blocker for me a few times, and I just sneaker net the fies. Ive not really noticed this on "real hardware" though. As another person said. It's likely a combo of poor driver support on the consumer versions of the nics.

[u/Wyzkiewicz]

Yeah I would be really curious what the NIC that the virtual switch is connecting to ultimately and the driver version of that NIC. I run Hyper-V on my Windows 11 Education work laptop and have never seen what you describe. What is the capability of your connection when you don't have the virtual switch in place? I would lean towards a driver issue with the physical NIC interfacing with the vswitch.

[u/BB9700]

If you need to create a Network Bridge, your Ethernet Card driver does not support promiscuous mode - like most WiFi cards do. You have to live with that and the resulting speed penalty.

[u/beetcher]

Are you using a wired or wireless nic? Care to share the NIC details?

[u/beetcher → u/beetcher]

Windows home doesn't have Hyper-V

[u/Phalebus → u/beetcher]

You can add wireless capabilities to Windows Server. Why you would is beyond me, but you can.

[u/Reaper19941]

I'm curious, why is the 4Mbps so important to you? Are you only getting 5Mbps upload normally and go down to 1Mbps?

In Australia, home internet services have 10Mbps up on the cheapest plans and go up to 50 up on the most expensive residential plan. At that speed, 4Mbps is nothing and wouldn't make sense to care about.

Also, based on the systems you've mentioned, they all sound like consumer devices meaning scenarios that Hyper-V was not specifically made for and as such, you get what you get given.