IP Addresses for network

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I have a project in VB, and i am trying to get all the IPv4 addresses of all other computers on the network. I have this code but it does not seem to work as it gets IPv6.

VB

Dim _IPHostEntry As Net.IPHostEntry = System.Net.Dns.GetHostEntry(System.Net.Dns.GetHostName)


        For Each ipadds As Net.IPAddress
        In _IPHostEntry.AddressList
            ListBox1.Items.Add(ipadds)
        Next

Please Help.

Posted 3-Feb-13 8:02am

TheTimer

Updated 3-Feb-13 8:16am

v2

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Comments

Zoltán Zörgő 3-Feb-13 14:41pm

And how do you know which are "all other computers on the network"? First of all what is the extent of the "network" in your situation?

TheTimer 3-Feb-13 15:02pm

All computers on the network = All computers connected to the same host a me.

Zoltán Zörgő 3-Feb-13 15:35pm

All computers connected to the same host as me is still underdefined. You are connected to codeproject host as me. Are we on the same network? Do you see the problem? Please try to define more precisely the extent, because the possible solution depends on it.

TheTimer 3-Feb-13 16:45pm

What ever IPv4s I would get if I type in "netstat" in cmd.exe.
I hope that is descriptive enough.

Mike Meinz 3-Feb-13 16:08pm

GetHostEntry gets the IP addresses of the specified host. It does not search for all IP addresses on the network. It returns both the IPv4 and the IPv6 address of the requested computer. The following code selects the IPv4 address:


Dim strIPAddress as String = "" ' This computer's IP Address
Dim strHostName as String = System.Net.Dns.GetHostName  ' This computer's name
Dim objAddressList() As System.Net.IPAddress = System.Net.Dns.GetHostEntry(strHostName).AddressList
For x = 0 To objAddressList.GetUpperBound(0)
    If objAddressList(x).AddressFamily = Net.Sockets.AddressFamily.InterNetwork then
        strIPAddress = objAddressList(x).ToString
        Exit For
    End If
Next

TheTimer 3-Feb-13 16:46pm

What is "strHostName" and "strIPAddress"?

Mike Meinz 3-Feb-13 18:32pm

Sorry. Thought that was obvious. I updated the solution to declare them and put in a comment for each of the declarations. This solution does not answer your question. It demonstrates the way to get the IPv4 address from the AddressList property of GetHostEntry.

TheTimer 3-Feb-13 20:47pm

Grate now no errors! Is there a variable that i can use to add them to a list box?

Mike Meinz 3-Feb-13 20:54pm

Yes there is. Lookup the ListBox control in the Help file and read about the ListBox methods.

TheTimer 3-Feb-13 21:06pm

That is not what I ment, let me reword that.
how do I get the list of IPs from that code?

PS: Thank you for helping

Mike Meinz 3-Feb-13 21:22pm

You don't. My comment said that this only demonstrated how to select the IPv4 address from an AddressList object. Furthermore, my comment said that this only returned the AddressList object for the requested computer. Solution 1 with the check for IPv4 type addresses look like what you need. Try reviewing information about these classes in the Help file.

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**Zoltán Zörgő** · Answer 1 · 2013-02-03T11:44:00

Quote:
What ever IPv4s I would get if I type in "netstat" in cmd.exe.

So netstat[^] used without parameters, displays active TCP connections.
Use IPGlobalProperties.GetActiveTcpConnections Method[^] to get all connections of your machine.

Imports System
Imports System.Net
Imports System.Net.NetworkInformation
 
Module Program
	Sub Main()
		Dim ipProperties As IPGlobalProperties = IPGlobalProperties.GetIPGlobalProperties()
			
			Dim tcpConnections As TcpConnectionInformation() = ipProperties.GetActiveTcpConnections()
 
			For Each info As TcpConnectionInformation In tcpConnections
				Console.WriteLine("Local : " & info.LocalEndPoint.Address.ToString() & ":" & info.LocalEndPoint.Port.ToString() & vbLf & "Remote : " & info.RemoteEndPoint.Address.ToString() & ":" & info.RemoteEndPoint.Port.ToString() & vbLf & "State : " & info.State.ToString() & vbLf & vbLf)
			Next
			Console.ReadLine()
	End Sub
End Module

You can use AddressFamily[^] property to filter connections for only IPv4 ones.