Fix network problems after Check Point Endpoint Security VPN connect and disconnect

AutoFixVpn.cmd

@echo off
start "" /min "C:\Program Files\PowerShell\7\pwsh.exe" -WindowStyle Hidden -ExecutionPolicy Bypass -Command "& '~\AutoFixVpn.ps1'"

AutoFixVpn.ps1

Add-Type -AssemblyName System.Windows.Forms
Add-Type -AssemblyName System.Drawing

$mainAdapter = "Ethernet"
$vpnIpPrefix = "192.168.59."
$vpnWasConnected = $false
$logFile = "$PSScriptRoot\vpn-fix.log"
$vpnAdapterName = "Ethernet 2"  # Name of your VPN adapter (adjust accordingly)

# -- Define the monitoring action
$timer = New-Object System.Windows.Forms.Timer
$timer.Interval = 5000  # 5 seconds

# -- Function to check VPN status by looking for an IP address
function Is-VpnConnected {
    $vpnAdapter = Get-NetAdapter | Where-Object { $_.Name -eq $vpnAdapterName }

    if ($vpnAdapter.Status -eq 'Up') {
        # Check if the adapter has a specific VPN IP address
        $vpnIp = (Get-NetIPAddress -InterfaceAlias $vpnAdapterName | Where-Object { $_.IPAddress -like "$vpnIpPrefix*" }).IPAddress
        if ($vpnIp) {
            return $true
        }
    }
    return $false
}

function Get-IconFromShell32 {
    param(
        [int]$iconIndex = 0
    )
    $shell32 = "$env:SystemRoot\System32\SHELL32.dll"
    $icon = [System.Drawing.Icon]::ExtractAssociatedIcon($shell32)
    # Use ExtractIcon via Win32 API for indexed icons
    $signature = @'
    [DllImport("shell32.dll", CharSet = CharSet.Auto)]
    public static extern IntPtr ExtractIcon(IntPtr hInst, string lpszExeFileName, int nIconIndex);
'@
    Add-Type -MemberDefinition $signature -Name 'Win32Icon' -Namespace 'Win32'
    $hIcon = [Win32.Win32Icon]::ExtractIcon([IntPtr]::Zero, $shell32, $iconIndex)
    if ($hIcon -eq [IntPtr]::Zero) { return $null }
    return [System.Drawing.Icon]::FromHandle($hIcon)
}

function Log($msg) {
    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    "$timestamp $msg" | Out-File -Append $logFile
    Write-Host "$timestamp $msg"
}

# -- Create tray icon
$notifyIcon = New-Object System.Windows.Forms.NotifyIcon
$notifyIcon.Icon = Get-IconFromShell32 -iconIndex 15  # Default icon (VPN connected)
$notifyIcon.Text = "VPN Fix Monitor"
$notifyIcon.Visible = $true

$vpnNowConnected = Is-VpnConnected
# -- Use a global scope to ensure persistence across timer ticks
$global:vpnWasConnected = $vpnNowConnected
$global:timer = $timer

# -- Function to change tray icon based on VPN status
function UpdateTrayIcon($isVpnConnected) {
    # Overlay icon logic: base icon for VPN status, overlay for monitoring state
    $baseIconIndex = if ($isVpnConnected) { 14 } else { 15 }
    $baseIcon = Get-IconFromShell32 $baseIconIndex

    # Overlay: green dot for monitoring ON, red dot for OFF
    $overlayColor = if ($global:timer.Enabled) { 'LimeGreen' } else { 'Red' }
    $overlaySize = 12

    # Create a new bitmap and draw base icon + overlay
    $bmp = New-Object System.Drawing.Bitmap $baseIcon.Width, $baseIcon.Height
    $g = [System.Drawing.Graphics]::FromImage($bmp)
    $g.DrawIcon($baseIcon, 0, 0)

    # Draw overlay circle at bottom-right
    $overlayBrush = New-Object System.Drawing.SolidBrush ([System.Drawing.Color]::$overlayColor)
    $x = $bmp.Width - $overlaySize - 2
    $y = $bmp.Height - $overlaySize - 2
    $g.FillEllipse($overlayBrush, $x, $y, $overlaySize, $overlaySize)
    $g.Dispose()

    # Set the tray icon
    $iconWithOverlay = [System.Drawing.Icon]::FromHandle($bmp.GetHicon())
    $notifyIcon.Icon = $iconWithOverlay

    # Tooltip text
    $monitoringStatus = if ($global:timer.Enabled) { "Monitoring ON" } else { "Monitoring OFF" }
    $vpnStatus = if ($isVpnConnected) { "VPN Connected" } else { "VPN Disconnected" }
    $notifyIcon.Text = "$vpnStatus ($monitoringStatus)"
}

# -- Function to show tray notifications
function ShowTrayNotification($title, $message, $icon) {
    $notifyIcon.ShowBalloonTip(3000, $title, $message, $icon)
}

$timer.Add_Tick({
    $vpnNowConnected = Is-VpnConnected

    # Log the current VPN connection status
    # Log "VPN Adapter status: $($vpnNowConnected)"

    # Only restart if VPN connection has changed
    if ($vpnNowConnected -and -not $global:vpnWasConnected) {
        Log "🟢 VPN connected — restarting adapter..."
        Restart-NetAdapter -Name $mainAdapter -Confirm:$false
        $notifyIcon.ShowBalloonTip(5000, "VPN Connected", "VPN connection established. Restarting adapter...", [System.Windows.Forms.ToolTipIcon]::Info)
        Start-Sleep -Seconds 2  # Add a small delay before continuing
        $global:vpnWasConnected = $true
        UpdateTrayIcon $true  # Change tray icon to reflect VPN connection
    }
    elseif (-not $vpnNowConnected -and $global:vpnWasConnected) {
        Log "🔴 VPN disconnected — restarting adapter..."
        Restart-NetAdapter -Name $mainAdapter -Confirm:$false
        $notifyIcon.ShowBalloonTip(5000, "VPN Disconnected", "VPN disconnected. Restarting adapter...", [System.Windows.Forms.ToolTipIcon]::Warning)
        Start-Sleep -Seconds 2  # Add a small delay before continuing
        $global:vpnWasConnected = $false
        UpdateTrayIcon $false  # Change tray icon to reflect VPN disconnection
    }
})

# -- Menu items
$menu = New-Object System.Windows.Forms.ContextMenuStrip

$startItem = $menu.Items.Add("✅ Start Monitoring")
$stopItem = $menu.Items.Add("⏹️ Stop Monitoring")
$openLogItem = $menu.Items.Add("📝 Open Log File")
$restartNetwork = $menu.Items.Add("🔄 Restart Network Adapter")
$exitItem = $menu.Items.Add("Exit")

$startItem.Add_Click({ 
    $global:timer.Start(); 
    Log "✅ Monitoring started"
    UpdateTrayIcon $global:vpnWasConnected
})
$stopItem.Add_Click({ 
    $global:timer.Stop(); 
    Log "⏹️ Monitoring stopped"
    UpdateTrayIcon $global:vpnWasConnected
})
$restartNetwork.Add_Click({ 
    Log "🔄 Restarting network adapter..."
    Restart-NetAdapter -Name $mainAdapter -Confirm:$false
    $notifyIcon.ShowBalloonTip(5000, "Network Restart", "Netwoek adapter restarted.", [System.Windows.Forms.ToolTipIcon]::Info)
})
$openLogItem.Add_Click({ 
    Invoke-Item $logFile 
})
$exitItem.Add_Click({
    $global:timer.Stop()
    $notifyIcon.Dispose()
    Log "🛑 Script exited"
    [System.Windows.Forms.Application]::Exit()
})

$notifyIcon.ContextMenuStrip = $menu

$timer.Start();

# -- Check VPN status when script starts
if ($vpnNowConnected) {
    Log "🟢 VPN connected on startup — no restart needed."
    UpdateTrayIcon $true
} else {
    Log "🔴 VPN not connected on startup"
    UpdateTrayIcon $false
}

Log "✅ Monitoring started" 

# -- Keep the tray app running
Log "🟢 VPN Fix tray app started"
[System.Windows.Forms.Application]::Run()

I am running Windows 11 as a virtual machine using VirtualBox with custom NAT networking configured. When connecting to and disconnecting form a VPN endpoint using Check Point Endpoint Security VPN, network connection is lost.

The purpose of this script is to run in the background and detect whenever VPN has connected or disconnected. When it detects changes it restarts the network adapter to restore the lost network connection.

Use AutFixVpn.cmd to run hidden in the background