1
Diagnostic step 1
Collect adapter state before and after suspend: run 'Get-NetAdapter | Format-Table -Auto' and save output to compare InterfaceIndex, GUID and ifAlias; this will document whether the driver re-created the adapter.
FULL AI ANALYSIS
Hyper‑V external virtual switch bound to Wi‑Fi stops forwarding traffic after Windows 11 host resumes from sleep
Generated Oct 3, 2026, 12:35:03 AM
Analysis summary
Wireless NIC drivers commonly reinitialize on suspend/resume and may present a new underlying adapter instance (new GUID/InterfaceIndex). Hyper‑V external switches are bound to the specific adapter instance; when the driver recreates the adapter, the binding becomes stale and the vSwitch no longer forwards traffic. Wired adapters tend to behave more stably across suspend/resume. This is a host-level binding issue rather than VM network stack fault.
Possible causes
Wi‑Fi driver reinitializes on resume, changing adapter identity and breaking Hyper‑V vSwitch binding.
90%Hyper‑V virtual switch binding code does not auto-rebind to a new adapter instance after driver reattachment.
90%Wireless adapters do not fully support NDIS features Hyper‑V expects across power cycles, causing vSwitch binding loss.
75%Power management/fast startup settings cause partial reinitialization that invalidates virtual switch mappings.
45%Suggested fixes
2
Diagnostic step 2
Workaround: create a small PowerShell resume script that rebinds the vSwitch to the physical adapter using 'Remove-VMSwitch -Name "External"' followed by 'New-VMSwitch -Name "External" -NetAdapterName "Wi‑Fi" -AllowManagementOS $true' (disruptive to VMs while rebind runs — test during maintenance).
3
Diagnostic step 3
Less disruptive: restart the 'Hyper‑V Virtual Machine Management' service after resume (reversible and faster than full reboot): 'Restart-Service vmms' (note that stopping this service may briefly stop VM management but usually preserves running VMs).
4
Diagnostic step 4
If possible, prefer a wired Ethernet connection for Hyper‑V external switches or use an internal/NAT switch setup with host ICS for wireless-only hosts to avoid binding to the flaky Wi‑Fi adapter.
5
Diagnostic step 5
Report the issue to the NIC vendor with collected adapter GUIDs and event timestamps; if reproducible on multiple hosts, escalate to Microsoft support with captured logs. Avoid disabling security features; test any script in a controlled window and back up VM states before applying changes.