Fix WSL2 internet connection while on VPN

Written by: Tushar Sharma

Featured image for Fix WSL2 internet connection while on VPN

Windows Subsystem for Linux (WSL2) provides native Linux environment for Windows. It's great alternative to cygwin which can't run native Linux apps. However WSL2 doesn't have out-of-box connectivity with internet once you connect with vpn.

Solution

Step 1

Open powershell and get the list of nameservers

Get-DnsClientServerAddress -AddressFamily IPv4 | Select-Object -ExpandProperty ServerAddresses

Step 2

Retrive search domains via powershell

Get-DnsClientGlobalSetting | Select-Object -ExpandProperty SuffixSearchList

Step 3

Open up wsl2, and run the following commands

# this will unlink the default wsl2 resolv.conf
sudo unlink /etc/resolv.conf 


# This config will prevent wsl2 from overwritting the resolve.conf file everytime you start wsl2
$ sudo bash -c 'echo "[network]" > /etc/wsl.conf'
$ sudo bash -c 'echo "generateResolvConf = false" >> /etc/wsl.conf'

$ sudo rm /etc/resolv.conf

# Add nameserver and search domain
$ sudo bash -c 'echo "nameserver 1.1.1.1" > /etc/resolv.conf'
$ sudo bash -c 'echo "nameserver 8.8.8.8" >> /etc/resolv.conf'
# Get following value from step 1
$ sudo bash -c 'echo "nameserver x.x.x.x" >> /etc/resolv.conf' 
# Get following value from step 2
$ sudo bash -c 'echo "search .com" >> /etc/resolv.conf'

# Make the new /etc/resolve.conf immutable
$ sudo chattr +i /etc/resolv.conf 

Remove any nameserver that starts with 172.* or 192.

Step 4

Restart wsl2 via powershell.

Restart-Service LxssManager

Finally you can connect to internet with vpn. To verify run the following command:

$ nslook www.google.com