Technical references: Powershell Network Tools

Few Powershell Network tools

This is when you are in an environment that won't let you install software. I've collected these from various sources. I use them often enough to keep it handy here.

Check for TCP Listener:

$socket = new-object net.sockets.tcpclient
$socket.connect("www.google.com",443)
$socket.connected
$socket = $null

Check for TCP Connections on your machine:

This is more than you really need, but it'll print a table of established connections every 5 seconds. If you just want the raw data and all the available connection state, just run lines 2 and 3.

do{
 $tcpproperties=[System.Net.NetworkInformation.IPGlobalProperties]::GetIPGlobalProperties()
 $connections=$tcpproperties.GetActiveTcpConnections()
 $output=@()
 foreach($conn in $connections){
   if($conn.State -eq 'Established'){
     $outputObj = New-Object -typename PSObject
     $outputObj | Add-Member -MemberType NoteProperty -Name "LocalAddress" -Value $conn.LocalEndPoint.Address 
     $outputObj | Add-Member -MemberType NoteProperty -Name "LocalPort" -Value $conn.LocalEndPoint.Port
     $outputObj | Add-Member -MemberType NoteProperty -Name "RemoteAddress" -Value $conn.RemoteEndPoint.Address
     $outputObj | Add-Member -MemberType NoteProperty -Name "RemotePort" -Value $conn.RemoteEndPoint.Port
     $outputObj | Add-Member -MemberType NoteProperty -Name "State" -Value $conn.State
     $output=$output + $outputObj
   }
 }
 $output | format-table
 sleep 5
}while($true)

Check for UDP Listener

For this one, I'm also illustrating a listener too. Good for troubleshooting firewall.

Receiver

Run this portion on your receive end and wait for traffic.

$udpObject = new-object system.net.sockets.udpclient(1433)
$udpObject.client.ReceiveTimeout = 10000
do{
  $remoteEndPoint = new-object System.Net.IPEndPoint([System.Net.IPAddress]::Any,0)
  $receiveBytes = $udpObject.Receive([ref]$remoteEndPoint)
  $a = New-Object System.Text.AsciiEncoding
  [String]$returnData = $a.GetString($receiveBytes)
  Write-host "Received: $($returnData.ToString())"
  Write-host "Sent from: $($remoteEndPoint.Address.ToString()) on their port: $($remoteEndPoint.port.ToString())"
  $ans = read-host "More (y/n)?"
}while($ans -ne 'n')
$udpObject.close()

Sender

Then run this from your remote machine to see the information show up on the remote end.

$udpObject = new-object system.net.sockets.udpclient(1433)
$udpObject.connect("10.10.10.1",1433)
$a = new-object System.Text.AsciiEncoding
$byte = $a.GetBytes("$(get-date)")
[void]$udpObject.send($byte,$byte.length)
$udpObject.close()

Check for UDP Connection

1 2	$udpProperties = [System.Net.NetworkInformation.IPGlobalProperties]::GetIPGlobalProperties() $udpProperties.GetActiveUDPListners()

Remote PowerShell Session

Again, more than you need, but incase you don't want to have to type in your password every time.

$servername = "mydesktop1"
$username = "domain\username"
$password = "password"
$secPassword = convertTo-SecureString $password -AsPlainText -Force
$mycred = New-Object System.Management.Automation.PSCredential($username,$secPassword)
enter-pssession -Credential $mycred -Computername $servername

Send Email

Good way to test your SMTP Server.

$SMTP = "mail.mycompany.net"
$Subject = "Test from $env:Computername"
$toaddress = "myemail@mycompany.net"
$fromaddress = $env:Computername + "@mycompany.net"
$body = "this message was sent via $SMTP at $(get-date)."
send-mailmessage -smtpserver $SMTP -to $toaddress -from $fromaddress -subject $subject -body $body

Technical references

Thursday, August 10, 2017

Powershell Network Tools