microsoft / microsoft/WSL

Microsoft Azure VFP Switch Filter Extension dropping packets from the external device (not the host)

Open
#41,345 4 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

emailed-logs network
Dominant language
C++
Stars
33.7k
Forks
1.8k
Avg merge
3d 17h
Merged PRs (30d)
116

Description

### Windows Version

Microsoft Windows 11 26200.8893

### WSL Version

2.7.11.0

### Are you using WSL 1 or WSL 2?

- [x] WSL 2
- [ ] WSL 1

### Kernel Version

6.18.33.2-2

### Distro Version

Ubuntu 22.04

### Other Software

_No response_

### Repro Steps

Here is my WSLConfig file.
[wsl2]
memory=8GB
processors=4
networkingMode=mirrored
dnsTunneling=true
firewall=true
autoProxy=true

[experimental]
hostAddressLoopback=true
sparseVhd=true

I am running Sql Server linux container inside wsl to host DB. Connection from the host to container on port 1433 works fine because of the hostAddressLoopback set to true to WSLConfig but when external machine tries to connect to same container using host ip it fails to connect. I have set True to DefaultInboundAction/DefaultOutboundAction for NetFirewallHyperVVMSetting. After analyzing the packets captured using pktmon I found that FSE switch adapter was dropping the packet with error code Invalid Packet. So I after few trials I found that when I disable Microsoft Azure VFP Switch Filter Extension everything works fine and it is turned on same error occurs.

### Expected Behavior

Since Microsoft Azure VFP Switch Filter Extension gets enabled by default mirrored mode networking to WSL should work fine with this filter extension on.

### Actual Behavior

When the Microsoft Azure VFP Switch Filter Extension is enabled on FSE Switch external connection to WSL does not work in mirrored mode.

### Diagnostic Logs

_No response_

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the failure with WSL 2 mirrored networking and the shown .wslconfig settings, then capture packets with pktmon while the Azure VFP Switch Filter Extension is enabled and disabled. Compare the external connection to the SQL Server container on port 1433; done means external hosts can connect with the filter enabled.

Written by the indexing model from the issue text.

Assessment

Tech stack
azure
Domain
networking, operating-systems
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.