Every five minutes or so, my entire Windows machine would drop off the network for a few seconds — not just WSL, the whole host. Browser tabs would stall, calls would drop, and it only happened while WSL2 was running. This is the story of finding that, plus the WSL memory-tuning landmines I hit right alongside it.
The flapping
The symptom was a host-wide network blip on a short, regular interval, correlated tightly with WSL2 being up. The cause: WSL2's default networking mode creates a virtual NAT switch on the Windows side, and on this machine that virtual switch was intermittently conflicting with the real network adapter — enough to cause the whole host to briefly renegotiate its connection.
The fix was switching WSL2's networking mode entirely, via .wslconfig (on Windows, not inside the Linux filesystem):
[wsl2]
