How to check Network port access and display useful message?

Question

I was trying to check whether the port is opened or not using powershell like follows.

(new-object Net.Sockets.TcpClient).Connect("10.45.23.109", 443)

This method works , but the output is not user-friendly. It means if there are no errors then it has access. Is there any way to check for success and display some message like " Port 443 is operational"?

2

see here http://poshcode.org/85 – CB. Mar 05 '12 at 12:00

score 67 · Answer 1 · edited Mar 26 '19 at 09:13

67

If you're running Windows 8/Windows Server 2012 or newer, you can use the Test-NetConnection command in PowerShell.

Ex:

Test-NetConnection -Port 53 -ComputerName LON-DC1

edited Mar 26 '19 at 09:13

EvilDr

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answered Sep 18 '14 at 23:33

SimonOzturk

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Test-NetConnection only works on Windows 8.x and Server 2012R2 and newer. – dragon788 Jan 06 '17 at 18:03
Down vote as `Test-NetConnection` isn't available until PS 5. – Brettski Sep 08 '17 at 21:04
@Brettski Your comment is flat wrong. Just tested on a Windows Server 2012 machine with PS4. It is, however, part of the [NetTCPIP module](https://learn.microsoft.com/en-us/powershell/module/nettcpip/?view=win10-ps), which is not available on Windows 7 and Windows Server 2008 R2 and lower. – jpmc26 Nov 10 '17 at 23:45
@jpmc26 Ah you're right it's a PowerShell 4 cmdlet. Mistakes happen. Down-vote removed. – Brettski Nov 12 '17 at 14:12

mshutov · Answer 2 · 2014-03-25T05:38:40.313

I improved Salselvaprabu's answer in several ways:

It is now a function - you can put in your powershell profile and use anytime you need
It can accept host as hostname or as ip address
No more exceptions if host or port unavaible - just text

Call it like this:

Test-Port example.com 999
Test-Port 192.168.0.1 80

function Test-Port($hostname, $port)
{
    # This works no matter in which form we get $host - hostname or ip address
    try {
        $ip = [System.Net.Dns]::GetHostAddresses($hostname) | 
            select-object IPAddressToString -expandproperty  IPAddressToString
        if($ip.GetType().Name -eq "Object[]")
        {
            #If we have several ip's for that address, let's take first one
            $ip = $ip[0]
        }
    } catch {
        Write-Host "Possibly $hostname is wrong hostname or IP"
        return
    }
    $t = New-Object Net.Sockets.TcpClient
    # We use Try\Catch to remove exception info from console if we can't connect
    try
    {
        $t.Connect($ip,$port)
    } catch {}

    if($t.Connected)
    {
        $t.Close()
        $msg = "Port $port is operational"
    }
    else
    {
        $msg = "Port $port on $ip is closed, "
        $msg += "You may need to contact your IT team to open it. "                                 
    }
    Write-Host $msg
}

score 16 · Accepted Answer · answered Mar 08 '12 at 07:06

Actually Shay levy's answer is almost correct but i got an weird issue as i mentioned in his comment column. So i split the command into two lines and it works fine.

$Ipaddress= Read-Host "Enter the IP address:"
$Port= Read-host "Enter the port number to access:"

$t = New-Object Net.Sockets.TcpClient
$t.Connect($Ipaddress,$Port)
    if($t.Connected)
    {
        "Port $Port is operational"
    }
    else
    {
        "Port $Port is closed, You may need to contact your IT team to open it. "
    }

Shay Levy · Answer 4 · 2012-03-05T13:03:01.880

14

You can check if the Connected property is set to $true and display a friendly message:

    $t = New-Object Net.Sockets.TcpClient "10.45.23.109", 443 

    if($t.Connected)
    {
        "Port 443 is operational"
    }
    else
    {
        "..."
    }

edited Mar 05 '12 at 13:03

answered Mar 05 '12 at 12:54

Shay Levy

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Buddy , I am facing weird issue with above solution. For example. I first used port 443 , it failed and displayed else part string. then I gave the port number which has access ( 80 ). It displayed if part string. again i changed the port number to 443 and it displayed if part string. ( it should have displayed else string) – Samselvaprabu Mar 06 '12 at 07:03
And this is enough to get a true/false response `(New-Object Net.Sockets.TcpClient "10.45.23.109", 443).Connected` – ndemou Jun 27 '19 at 11:03

score 7 · Answer 5 · answered Jul 18 '17 at 19:41

With the latest versions of PowerShell, there is a new cmdlet, Test-NetConnection.

This cmdlet lets you, in effect, ping a port, like this:

Test-NetConnection -ComputerName <remote server> -Port nnnn

I know this is an old question, but if you hit this page (as I did) looking for this information, this addition may be helpful!

score 4 · Answer 6 · edited Jul 17 '15 at 16:10

I tried to improve the suggestion from mshutov. I added the option to use the output as an object.

 function Test-Port($hostname, $port)
    {
    # This works no matter in which form we get $host - hostname or ip address
    try {
        $ip = [System.Net.Dns]::GetHostAddresses($hostname) | 
            select-object IPAddressToString -expandproperty  IPAddressToString
        if($ip.GetType().Name -eq "Object[]")
        {
            #If we have several ip's for that address, let's take first one
            $ip = $ip[0]
        }
    } catch {
        Write-Host "Possibly $hostname is wrong hostname or IP"
        return
    }
    $t = New-Object Net.Sockets.TcpClient
    # We use Try\Catch to remove exception info from console if we can't connect
    try
    {
        $t.Connect($ip,$port)
    } catch {}

    if($t.Connected)
    {
        $t.Close()
        $object = [pscustomobject] @{
                        Hostname = $hostname
                        IP = $IP
                        TCPPort = $port
                        GetResponse = $True }
        Write-Output $object
    }
    else
    {
        $object = [pscustomobject] @{
                        Computername = $IP
                        TCPPort = $port
                        GetResponse = $False }
        Write-Output $object

    }
    Write-Host $msg
}

score 4 · Answer 7 · answered Oct 19 '17 at 21:54

If you are using older versions of Powershell where Test-NetConnection isn't available, here is a one-liner for hostname "my.hostname" and port "123":

$t = New-Object System.Net.Sockets.TcpClient 'my.hostname', 123; if($t.Connected) {"OK"}

Returns OK, or an error message.

score 0 · Answer 8 · answered Oct 25 '17 at 13:10

Great answer by mshutov & Salselvaprabu. I needed something a little bit more robust, and that checked all IPAddresses that was provided instead of checking only the first one.

I also wanted to replicate some of the parameter names and functionality than the Test-Connection function.

This new function allows you to set a Count for the number of retries, and the Delay between each try. Enjoy!

function Test-Port {

    [CmdletBinding()]
    Param (
        [string] $ComputerName,
        [int] $Port,
        [int] $Delay = 1,
        [int] $Count = 3
    )

    function Test-TcpClient ($IPAddress, $Port) {

        $TcpClient = New-Object Net.Sockets.TcpClient
        Try { $TcpClient.Connect($IPAddress, $Port) } Catch {}

        If ($TcpClient.Connected) { $TcpClient.Close(); Return $True }
        Return $False

    }

    function Invoke-Test ($ComputerName, $Port) {

        Try   { [array]$IPAddress = [System.Net.Dns]::GetHostAddresses($ComputerName) | Select-Object -Expand IPAddressToString } 
        Catch { Return $False }

        [array]$Results = $IPAddress | % { Test-TcpClient -IPAddress $_ -Port $Port }
        If ($Results -contains $True) { Return $True } Else { Return $False }

    }

    for ($i = 1; ((Invoke-Test -ComputerName $ComputerName -Port $Port) -ne $True); $i++)
    {
        if ($i -ge $Count) {
            Write-Warning "Timed out while waiting for port $Port to be open on $ComputerName!"
            Return $false
        }

        Write-Warning "Port $Port not open, retrying..."
        Sleep $Delay
    }

    Return $true

}

score 0 · Answer 9 · answered Apr 01 '18 at 21:49

boiled this down to a one liner sets the variable "$port389Open" to True or false - its fast and easy to replicate for a list of ports

try{$socket = New-Object Net.Sockets.TcpClient($ipAddress,389);if($socket -eq $null){$Port389Open = $false}else{Port389Open = $true;$socket.close()}}catch{Port389Open = $false}

If you want ot go really crazy you can return the an entire array-

Function StdPorts($ip){
    $rst = "" |  select IP,Port547Open,Port135Open,Port3389Open,Port389Open,Port53Open
    $rst.IP = $Ip
    try{$socket = New-Object Net.Sockets.TcpClient($ip,389);if($socket -eq $null){$rst.Port389Open = $false}else{$rst.Port389Open = $true;$socket.close();$ipscore++}}catch{$rst.Port389Open = $false}
    try{$socket = New-Object Net.Sockets.TcpClient($ip,53);if($socket -eq $null){$rst.Port53Open = $false}else{$rst.Port53Open = $true;$socket.close();$ipscore++}}catch{$rst.Port53Open = $false}
    try{$socket = New-Object Net.Sockets.TcpClient($ip,3389);if($socket -eq $null){$rst.Port3389Open = $false}else{$rst.Port3389Open = $true;$socket.close();$ipscore++}}catch{$rst.Port3389Open = $false}
    try{$socket = New-Object Net.Sockets.TcpClient($ip,547);if($socket -eq $null){$rst.Port547Open = $false}else{$rst.Port547Open = $true;$socket.close();$ipscore++}}catch{$rst.Port547Open = $false}
    try{$socket = New-Object Net.Sockets.TcpClient($ip,135);if($socket -eq $null){$rst.Port135Open = $false}else{$rst.Port135Open = $true;$socket.close();$SkipWMI = $False;$ipscore++}}catch{$rst.Port135Open = $false}
    Return $rst
}

score -1 · Answer 10 · edited Apr 18 '19 at 15:14

-1

When scanning closed port it becomes unresponsive for long time. It seems to be quicker when resolving fqdn to ip like:

[System.Net.Dns]::GetHostAddresses("www.msn.com").IPAddressToString

edited Apr 18 '19 at 15:14

Bhargav Rao

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answered Apr 17 '15 at 18:05

uzjsme

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How to check Network port access and display useful message?

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