BSOD windows server 2025 vmswitch.sys

Hello Anthony LEROUX

I have suggestion as below:

Check Windows and Driver Updates

• Firmware/Driver Updates: Ensure all network card firmware and drivers are up to date. Dell provides updates for their Broadcom, Intel, or Mellanox NICs. Outdated drivers are a common cause of vmswitch.sys crashes.
• Windows Updates: Make sure Windows Server 2022 Datacenter is fully patched, especially for network and Hyper-V related updates. 

 Testing and Isolation

• Try reproducing the issue in a controlled way:
  • Unplug one NIC at a time.
  • Test with different teaming modes.
  • Test with the latest drivers.

Best regard

Alan Meng

Hi, I’m Henry, and I want to share some insights on this issue.

I am not sure if you're Using SET (Switch Embedded Teaming). Windows Server 2016+ recommends SET over traditional NIC Teaming (LBFO) for Hyper-V. If using LBFO:

• Consider switching to SET with the following command: New-VMSwitch -EnableEmbeddedTeaming $true
• LBFO is deprecated in favor of SET and may cause instability when used with VMSwitch.

Here are some potential causes I’ve identified

1. NIC Teaming Instability

Unplugging two NICs from a four-NIC team may cause instability in VMSwitch, leading to a crash.

Try disabling NIC teaming temporarily and testing if the issue persists.

1. Dell PowerEdge R650 and recent Broadcom/Intel NICs (e.g., QLogic, Intel X710, etc.) require updated drivers/firmware for Windows Server 2022/2025.
2. Some users report instability with logical switch settings in System Center Virtual Machine Manager (SCVMM). If using SCVMM, try managing NIC teaming locally instead of through SCVMM.
3. If possible, test the same setup on Windows Server 2022 to compare behavior.

I hope this helps point you in the right direction for your troubleshooting