Test-Port

Test if a port on a remote computer is open or not.

Param(
[Parameter(Position=0, Mandatory=$true, ValueFromPipeline=$true, HelpMessage="A servername or IP address must be specified")]
[string]$srv,
[Parameter(Position=1, Mandatory=$true, ValueFromPipeline=$true, HelpMessage="A port number must be specified")]
[string]$port,
[Parameter(Position=2)]
[string]$timeout=1000
)
$ErrorActionPreference = "SilentlyContinue"
$tcpclient = New-Object system.Net.Sockets.TcpClient
$iar = $tcpclient.BeginConnect($srv, $port, $null, $null)
$wait = $iar.AsyncWaitHandle.WaitOne($timeout, $false)
if (!$wait)
{
$tcpclient.Close()
Write-Host "Connection Timeout" -ForegroundColor DarkYellow
$failed = $true
}
else
{
$Error.Clear()
$tcpclient.EndConnect($iar) | Out-Null
if ($Error[0]) {
Write-Host $Error[0] -ForegroundColor DarkYellow
$failed = $true
}
$tcpclient.Close()
}
if ($failed) {Write-Host "TCP Port $port on server $srv is closed!" -ForegroundColor DarkRed} else {Write-Host "TCP Port $port on server $srv is open!" -ForegroundColor DarkGreen}