WSL2 Cisco AnyConnect VPN Client Networking Connection Issue Workaround

README.md

How to use the above files?

Step 1: Copy files updateInterfaceMetric.ps1, updateDns.ps1, autodns.sh to your Windows path %HOMEPATH%\WSL2\scripts, if not exists, create this folder.

Step 2: Win+R Run taskschd.msc will open "Task Schedulder" application, import two tasks with files UpdateInterfaceMetric.xml, updateDns.xml one by one.

autodns.sh

#!/bin/bash

#Update DNS in file /etc/resolv.conf based on network connection status (up or down)

POWERSHELL_CMD='/mnt/c/Windows/System32/WindowsPowerShell/v1.0/powershell.exe'

# Get interface names of vpn,ethernet,wifi which are up status.
GET_INTERFACE_NAMES="Get-NetAdapter \
    | Where-Object -Property InterfaceDescription -Match \"Cisco AnyConnect|Gigabit|Wi.*Fi\" \
    | Where-Object -Property Status -eq \"Up\" \
    | Select-Object -ExpandProperty Name"

#echo "$GET_INTERFACE_NAMES"
INTERFACE_NAMES=$($POWERSHELL_CMD -Command "$GET_INTERFACE_NAMES")

COMBILED_NAMES=$(echo -e "$INTERFACE_NAMES" |tr -d '\r'|tr '\n' '|')
#echo "$COMBILED_NAMES"

# Get dns names by interface names
GET_DNS_NAMES="Get-DnsClientServerAddress -AddressFamily IPv4 \
    | Where-Object -Property InterfaceAlias -Match \"$COMBILED_NAMES\" \
    | Select-Object -ExpandProperty ServerAddresses"
#echo "$GET_DNS_NAMES"
DNS_NAMES=$($POWERSHELL_CMD -Command "$GET_DNS_NAMES")

echo -e "\n------------current /etc/resolv.conf------------"
if [ -L /etc/resolv.conf ]; then
    unlink /etc/resolv.conf
else
    cat /etc/resolv.conf
fi

#Update /etc/resolv.conf
{
    for i in $DNS_NAMES; do
        echo nameserver "$i"
    done
} | tr -d '\r' | tee /etc/resolv.conf > /dev/null

echo -e "\n------------updated /etc/resolv.conf------------"
cat /etc/resolv.conf

updateDns.ps1

# Update DNS of wsl based on networking status change(up or down)
# Event ids generated by Cisco AnyConnect when connection termination
#2039: VPN Established and Passing Data
#2061: Network Interface for the VPN has gone down
#2010: VPN Termination
#2041: The entire VPN connection has been re-established.

$distro="Ubuntu"
$user=((Get-WMIObject -ClassName Win32_ComputerSystem).Username).Split('\')[1]
wsl.exe -d $distro -u root /mnt/c/Users/$user/WSL2/scripts/autodns.sh

updateDns.xml

<?xml version="1.0" encoding="UTF-16"?>
<Task version="1.2" xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
  <RegistrationInfo>
    <Date>2021-10-14T10:35:06.9051925</Date>
    <Author>CCR\deyinche</Author>
    <Description>Update DNS of wsl based on networking status change(up or down)</Description>
    <URI>\WSL2\updateDns</URI>
  </RegistrationInfo>
  <Triggers>
    <EventTrigger>
      <Enabled>true</Enabled>
      <Subscription>&lt;QueryList&gt;&lt;Query Id="0" Path="Cisco AnyConnect Secure Mobility Client"&gt;&lt;Select Path="Cisco AnyConnect Secure Mobility Client"&gt;*[System[Provider[@Name='acvpnagent'] and (EventID=2039 or EventID=2010 or EventID=2061 or EventID=2041)]]&lt;/Select&gt;&lt;/Query&gt;&lt;/QueryList&gt;</Subscription>
    </EventTrigger>
  </Triggers>
  <Principals>
    <Principal id="Author">
      <UserId>S-1-5-21-1757981266-725345543-1404487317-531068</UserId>
      <LogonType>InteractiveToken</LogonType>
      <RunLevel>HighestAvailable</RunLevel>
    </Principal>
  </Principals>
  <Settings>
    <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
    <DisallowStartIfOnBatteries>false</DisallowStartIfOnBatteries>
    <StopIfGoingOnBatteries>true</StopIfGoingOnBatteries>
    <AllowHardTerminate>true</AllowHardTerminate>
    <StartWhenAvailable>false</StartWhenAvailable>
    <RunOnlyIfNetworkAvailable>false</RunOnlyIfNetworkAvailable>
    <IdleSettings>
      <StopOnIdleEnd>true</StopOnIdleEnd>
      <RestartOnIdle>false</RestartOnIdle>
    </IdleSettings>
    <AllowStartOnDemand>true</AllowStartOnDemand>
    <Enabled>true</Enabled>
    <Hidden>false</Hidden>
    <RunOnlyIfIdle>false</RunOnlyIfIdle>
    <WakeToRun>false</WakeToRun>
    <ExecutionTimeLimit>PT72H</ExecutionTimeLimit>
    <Priority>7</Priority>
  </Settings>
  <Actions Context="Author">
    <Exec>
      <Command>Powershell.exe</Command>
      <Arguments>-WindowStyle Hidden -NonInteractive -ExecutionPolicy Bypass -File %HOMEPATH%\WSL2\scripts\updateDns.ps1</Arguments>
    </Exec>
  </Actions>
</Task>

updateInterfaceMetric.ps1

# Update Cisco AnyConnect VPN Client InterfaceMetric to a higer value 6000
# Event ids generated by Cisco AnyConnect when connection established
# 2039: VPN Established and Passing Data
# 2041: The entire VPN connection has been re-established.

Get-NetAdapter | Where-Object {$_.InterfaceDescription -Match "Cisco AnyConnect"} | Set-NetIPInterface -InterfaceMetric 6000

UpdateInterfaceMetric.xml

<?xml version="1.0" encoding="UTF-16"?>
<Task version="1.2" xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
  <RegistrationInfo>
    <Date>2021-10-14T10:31:18.7113087</Date>
    <Author>CCR\deyinche</Author>
    <Description>Update Interface Metric of Cisco AnyConnect VPN Client to higer value 6000</Description>
    <URI>\WSL2\UpdateInterfaceMetric</URI>
  </RegistrationInfo>
  <Triggers>
    <EventTrigger>
      <Enabled>true</Enabled>
      <Subscription>&lt;QueryList&gt;&lt;Query Id="0" Path="Cisco AnyConnect Secure Mobility Client"&gt;&lt;Select Path="Cisco AnyConnect Secure Mobility Client"&gt;*[System[Provider[@Name='acvpnagent'] and (EventID=2039 or EventID=2041)]]&lt;/Select&gt;&lt;/Query&gt;&lt;/QueryList&gt;</Subscription>
    </EventTrigger>
  </Triggers>
  <Principals>
    <Principal id="Author">
      <UserId>S-1-5-21-1757981266-725345543-1404487317-531068</UserId>
      <LogonType>InteractiveToken</LogonType>
      <RunLevel>HighestAvailable</RunLevel>
    </Principal>
  </Principals>
  <Settings>
    <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
    <DisallowStartIfOnBatteries>false</DisallowStartIfOnBatteries>
    <StopIfGoingOnBatteries>true</StopIfGoingOnBatteries>
    <AllowHardTerminate>true</AllowHardTerminate>
    <StartWhenAvailable>false</StartWhenAvailable>
    <RunOnlyIfNetworkAvailable>false</RunOnlyIfNetworkAvailable>
    <IdleSettings>
      <StopOnIdleEnd>true</StopOnIdleEnd>
      <RestartOnIdle>false</RestartOnIdle>
    </IdleSettings>
    <AllowStartOnDemand>true</AllowStartOnDemand>
    <Enabled>true</Enabled>
    <Hidden>false</Hidden>
    <RunOnlyIfIdle>false</RunOnlyIfIdle>
    <WakeToRun>false</WakeToRun>
    <ExecutionTimeLimit>PT72H</ExecutionTimeLimit>
    <Priority>7</Priority>
  </Settings>
  <Actions Context="Author">
    <Exec>
      <Command>Powershell.exe</Command>
      <Arguments>-WindowStyle Hidden -NonInteractive -ExecutionPolicy Bypass -File %HOMEPATH%\WSL2\scripts\updateInterfaceMetric.ps1</Arguments>
    </Exec>
  </Actions>
</Task>

This worked perfectly. Huge thanks for sharing it.

P.S. Mine is and worked just fine as "Ubuntu", with no version number.