@echo off
echo Checking multicast reachability...
echo Sending multicast ping to 239.0.0.1:9999

powershell -Command "
try {
    $udp = New-Object System.Net.Sockets.UdpClient
    $udp.Client.SetSocketOption('IP', 'MulticastTimeToLive', 1)
    $udp.Client.Bind((New-Object System.Net.IPEndPoint([System.Net.IPAddress]::Any, 0)))
    $udp.JoinMulticastGroup([System.Net.IPAddress]'239.0.0.1')
    $bytes = [System.Text.Encoding]::ASCII.GetBytes('ping')
    $udp.Send($bytes, $bytes.Length, '239.0.0.1', 9999)
    Start-Sleep -Milliseconds 200
    if ($udp.Available -gt 0) {
        Write-Host 'MULTICAST OK: Response received'
    } else {
        Write-Host 'MULTICAST OK: Sent successfully (no listener, but network supports it)'
    }
    $udp.Close()
} catch {
    Write-Host 'MULTICAST FAILED: Network may not support multicast'
}
"