Windows sets virtual network adapter down

[cpebble]

Windows Version

Microsoft Windows [Version 10.0.26100.7392]

WSL Version

2.6.2.0

Are you using WSL 1 or WSL 2?

• WSL 2
• WSL 1

Kernel Version

6.6.87.2-microsoft-standard-WSL2

Distro Version

Arch Linux

Other Software

Vagrant: 2.4.9
With provider:
Oracle VirtualBox: 7.2.4

Repro Steps

Using mirrored networking
Starting a VM, using virtualbox "Host-Only Adapter" which assigns addresses on 192.168.56.1/24

By default this adapter is mirrored but not assigned an ip or enabled. Looking through ipconfig.exe /all the physical address can be found. Looking in ip link the interface can be determined.
Assume eth3 is the interface, enable the interface like so:

sudo ip addr add dev eth3 192.168.56.1/24
sudo ip link set eth3 up

Then connectivity works between vms and wsl.

Expected Behavior

1. That this adapter is enabled automatically. At least i expect this is what "mirrored" implies
2. That the adapter stays up

Actual Behavior

The adapter goes down at random intervals(seconds or minutes). In linux, with the errors:

systemd-networkd[93]: eth3: Link DOWN
systemd-networkd[93]: eth3: Lost carrier

From what i see in logs this seems to be as a result of some dns change reapplying the network state before adapter is set up

Diagnostic Logs

I managed to catch a pretty clean log file
WslLogs-2025-12-22_08-39-43.zip

[github-actions]

Diagnostic information

.wslconfig found
Detected appx version: 2.6.2.0

[cpebble]

Hello again, and happy new years.

I am still experiencing this issue; I can see it has been tagged correctly, but no further comments. Do i need to provide further information?

For reference, i am running this script, using the daemon function to run it in a loop in the background. This works for shorter jobs but is not reliable enough for persistent ssh connections etc.

#!/usr/bin/env bash
IP="192.168.56.1/24"

daemon () {
    IF=$1
    if [[ -z "$IF" ]]; then
        exit 1
    fi
    while sleep 10s; do
        if ip link show "$IF" | grep -q DOWN; then
            sudo ip link set "$IF" up
        fi
    done
}

# Gather info
IPINFO=$(ipconfig.exe /all | grep "192.168.56.1" -B 4)
PHYS=$(echo $IPINFO | grep -oE "([A-F0-9]{2}-?){6}" \
    | tr -d "-" | tr '[:upper:]' '[:lower:]')
echo "Found Physical Address: $PHYS"

# Pick interface
INTERFACE=$(ip addr | grep "$PHYS" -B 2 | grep -Eo "(eth[0-9])")
echo "Found Interface: $INTERFACE"
echo "$(ip addr show $INTERFACE)"

# Decide if we need IP
if ! ( ip addr show "$INTERFACE" | grep -q "192.168.56"); then
    echo -n "Add IP $IP?[y/N] "; read -n 1 prompt
    echo ""
    if [[ "${prompt,,}" == "y" ]]; then
        sudo ip addr add dev "$INTERFACE" "$IP"
    fi
fi

# Decide if we need UP
if ( ip link show "$INTERFACE" | head -n 1 | grep -q "DOWN"); then
    echo -n "Set UP?[y/N] "; read -n 1 prompt
    echo ""
    if [[ "${prompt,,}" == "y" ]]; then
        sudo ip link set "$INTERFACE" up
    fi
else
    echo "Link is already up"
fi

if [[ "$1" == "loop" ]]; then
    echo "Running loop"
    daemon "$INTERFACE"
fi