Send-UDPDatagram.ps1

1. <#  
2. .SYNOPSIS 
3.     Sends a UDP datagram to a port 
4. .DESCRIPTION 
5.     This script used system.net.socckets to send a UDP 
6.     datagram to a particular port. Being UDP, there's 
7.     no way to determine if the UDP datagram actually 
8.     was received.  
9.     for this sample, a port was chosen (20000). 
10. .NOTES 
11.     File Name  : Send-UDPDatagram 
12.     Author     : Thomas Lee - tfl@psp.co.uk 
13.     Requires   : PowerShell V2 CTP3 
14. .LINK 
15.     http://www.pshscripts.blogspot.com 
16. .EXAMPLE 
17. #> 
18.  
19. ### 
20. #  Start of Script 
21. ## 
22.  
23. # Define port and target IP address 
24. # Random here! 
25. [int] $Port = 20000 
26. $IP = "10.10.1.100" 
27. $Address = [system.net.IPAddress]::Parse($IP) 
28.  
29. # Create IP Endpoint 
30. $End = New-Object System.Net.IPEndPoint $address, $port 
31.  
32. # Create Socket 
33. $Saddrf   = [System.Net.Sockets.AddressFamily]::InterNetwork 
34. $Stype    = [System.Net.Sockets.SocketType]::Dgram 
35. $Ptype    = [System.Net.Sockets.ProtocolType]::UDP 
36. $Sock     = New-Object System.Net.Sockets.Socket $saddrf, $stype, $ptype 
37. $Sock.TTL = 26 
38.  
39. # Connect to socket 
40. $sock.Connect($end) 
41.  
42. # Create encoded buffer 
43. $Enc     = [System.Text.Encoding]::ASCII 
44. $Message = "Jerry Garcia Rocks`n"*10 
45. $Buffer  = $Enc.GetBytes($Message) 
46.  
47. # Send the buffer 
48. $Sent   = $Sock.Send($Buffer) 
49. "{0} characters sent to: {1} " -f $Sent,$IP 
50. "Message is:" 
51. $Message 
52. # End of Script 

 

If you run this script and are using WireShark to capture the network traffic, you might see something like this:

From this trace, you can see the UDP Datagram that was sent. And since the port does not exist on the target machine (10.10.1.100), that machine returns a Destination Port Unreachable as expected.

Technorati Tags: UDP,PowerShell,Scripts,System.Net.IPEndpoint,System.Net.Sockets