Monitor Cisco switch IGMP groups

cisco-igmp-monitor.ps1

function Get-CiscoIGMPGroups {
    return plink -ssh cisco@10.10.10.17 -pw cisco -batch "sh ip igmp snooping groups | include 224.0.1.129" 2>$null | ? {$_.Length -gt 0};
}

Write-Output "Starting IGMP group monitoring."
Write-Output "Press any key to exit..."
Write-Output "";

$prevEntry = "";
do {
    $entry = Get-CiscoIGMPGroups;
    if($entry -ne $prevEntry) {
        Write-Output "IGMP Group membership changed:"
        Write-Output $((Get-Date).ToString().Trim());
        if($entry.Length -gt 0) {
            Write-Output $entry;
        } else {
            Write-Output "(group empty)";
        }
    }
    $prevEntry = $entry;
    Start-Sleep -Seconds 2;
} until ([System.Console]::KeyAvailable);

Usage: .\igmplog.ps1 | Tee-Object -FilePath IGMPLog.txt