WSL2 Mirrored Mode - No Interfaces except LOCALHOST

[joslinpr]

Windows Version

Windows 11 GAC 23H2 (cmd.exe /c ver reports Microsoft Windows [Version 10.0.22631.5335]?)

WSL Version

0.0.0.0

Are you using WSL 1 or WSL 2?

• WSL 2
• WSL 1

Kernel Version

5.15.167.4-1

Distro Version

Ubuntu 22.04.5 LTS; Red Hat Enterprise Linux release 9.5 (Plow)

Other Software

WSL version: 2.4.13.0
Kernel version: 5.15.167.4-1
WSLg version: 1.0.65
MSRDC version: 1.2.5716
Direct3D version: 1.611.1-81528511
DXCore version: 10.0.26100.1-240331-1435.ge-release
Windows version: 10.0.22631.5335

When I start WSL.exe with "networkMode=mirrored", only the loopback interface is created. (Running wsl-vpnkit, the wsltap interface is also created, but fails since it cannot reach the network.)

Per #10650, I have tried it with "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters" set to 0xFF (default on our laptops), and set to 0x20. After terminating the distros and shutting down and restarting WSL.exe, the problem recurs on both distros (Ubuntu, RHEL).

I have verified that "Windows Defender Firewall with Advanced Security" is off (corporate policy).

Per #12399, I ran a webserver on Windows. It is accessible from Windows at http://127.0.0.1:8100. It is not accessible from either distro at any of the addresses configured on loopback: 0.0.0.0, 127.0.0.1, or 10.255.255.254.

Per #12632, Does not seem to be relevant, but does mention wsl-vpnkit. I believe the wsl-vpnkit issue is a symptom, not a cause.

Repro Steps

From windows:
wsl.exe --terminate -D RHEL91
wsl.exe --shutdown
(make config changes)
wsl.exe -d RHEL91 date
Inside RHEL91:

$  ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet 10.255.255.254/32 brd 10.255.255.254 scope global lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
973: wsltap: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
$ ip route show
$

In addition, the linux NetworkManager tools (nmtui, nmcli) do not see any links, so you cannot "Activate A Connection".

Additionally, running with networkMode=nat is not fully working. That mode worked fine last week. Corporate installed updates in the last week, but I do not know which ones. (I tried mirrored mode since nat mode only shows eth0, does not set a default route, and has connectivity problems to some networks. That's an issue for another day!)

Expected Behavior

I expect ip link show to have 3 interfaces: loopback, eth0, and wsltap. I expect a subnet limited route on eth0, and a default route on eth0.

Actual Behavior

 $ ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet 10.255.255.254/32 brd 10.255.255.254 scope global lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
973: wsltap: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000

Diagnostic Logs

.wslconfig:

[wsl2]
autoProxy=false
guiApplications=true

[experimental]
autoMemoryReclaim=gradual
networkingMode=mirrored
``
Network logs will be incomplete.  WSL distros are not installed for my Admin account, and it does not have internet access.  I ran it as my ordinary user account.

[WslNetworkingLogs-2025-05-15_11-34-33.zip](https://github.com/user-attachments/files/20231014/WslNetworkingLogs-2025-05-15_11-34-33.zip)