This article is contributed. See the original author and article here.

The Problem


So recently I was trying to run some kubectl commands using WSL2 to my home K8S cluster and encountered some strange events. Everything had worked fine when using WSL but for some reason I could now only ping external devices to my laptop (Router, Switch, Printer etc).


 


My Configuration


So just for clarification I have my configuration set like this.



  • My local network runs a 192.168.1.0/24 subnet.

  • My laptop runs as 192.168.1.10.

  • Hyper-V installed on the laptop.

  • WSL2 installed and running Ubuntu 18.04.

    • WSL vSwitch configured in Hyper-V Virtual Switch Manager as “Internal Network”.



  • Hyper-V configured with a dedicated vSwitch for Kubernetes (K8s-Switch).

    • Set as “Internal Network”.



  • 3 x Ubuntu 18.04 Kubernetes VMs configured below.

    • k8s-master-01 (10.10.10.101/24).

    • k8s-worker-01 (10.10.10.111/24).

    • k8s-worker-02 (10.10.10.112/24).




The worker and the nodes are all configured to route traffic correctly and can actively ping my host and resolve external domains.


 


The Investigation


After conducting some internet-based investigation, I found discovered I was not the only person seeing this, and an issue was already raised on GitHub under the Microsoft/WSL https://github.com/microsoft/WSL/issues/4288.


 


There are some great discussions around the subject on here, but for anyone who wants to know the resolution that worked for me, keep reading.


 


The Resolution


After trying a few different suggestions, the best resolution I have found is listed by jonaskuke.


Essentially, we needed to set Forwarding to be enabled across the two v-Switches. Using this command (with admin rights) based on my v-Switch names works.


 


 


 

Get-NetIPInterface | where {$_.InterfaceAlias -eq 'vEthernet (WSL)' -or $_.InterfaceAlias -eq 'vEthernet (K8s-Switch)'} | Set-NetIPInterface -Forwarding Enabled

 


 


 


There are some discussions around post reboot persistency as it appears the setting is discarded post reboot, which may be due to the WSL v-Switch taking a while to imitate. However, keep this command in a .ps1 file and all is good.


 

Brought to you by Dr. Ware, Microsoft Office 365 Silver Partner, Charleston SC.

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